Verify the ERPNext integration live and fix the defects it found (Phase F4)

Ran the push flow against ERPNext 15.121.6 on a plain site and on a site with India Compliance 15.32.0 (podman, scripts/erpnext-e2e). 15 ignored live tests pass on both.

Fixes, each covered by a mock-based test:
- load_options no longer fails on a plain site: the India Compliance-only gstin field is dropped on a 417 and retried.
- Code-less rows with fractional hours or minutes send stock_uom, since ERPNext defaults it to Nos.
- A created document whose total differs from Voiced's (ERPNext's default Banker's Rounding on half-paise ties) is recorded as a conflict, kept as a draft, not submitted and not given a PDF. The message names Commercial Rounding as the fix.
- An existing customer address is reused instead of creating a duplicate on every first push. A bare creation order-by is not used with a Dynamic Link filter.
- A re-adopted document no longer gets a second copy of the PDF.
- Reverse charge: India Compliance rejects is_reverse_charge unless tax rows are negative RCM amounts, so the flag is sent as 0 with a warning that the invoice lands as a normal taxed invoice.
- The 16-character name rule is checked locally in mirror mode under India Compliance, and a TDS-only payment is refused locally with the reason.

Payment Entry mapping verified: bank_account is the Account name (paid_to), paid and received amounts equal the cash received, allocated_amount is cash plus TDS, and TDS is one positive deductions row. The integration user needs the Accounts User and Sales User roles.

Not verified: ERPNext v14 and v16, other India Compliance versions, the Tauri commands and UI against a live site, SEZ and overseas customers, UTGST supplier states, TLS sites, e-invoicing.

docs/voiced-invoice-v1.md

@@ -0,0 +1,51 @@
+# voiced.invoice.v1
+
+A neutral export of issued invoices for software Voiced has no direct integration with. Choose invoices in the
+History list (checkboxes) or open one, then use "Export selected (voiced.invoice.v1 JSON)" or "(line items CSV)".
+The code is `src/lib/invoiceExportV1.ts`; `src/lib/__golden__/invoice-v1.golden.json` is a full example.
+
+## Rules
+
+- **Money is exact.** Every amount appears twice: `<name>_paise` (an integer) and `<name>` (a decimal string with two
+  places, e.g. `"7310.10"`). Nothing is a float. Rates (percent) are decimal strings such as `"9"` or `"6.25"`.
+- **Deterministic.** The same invoices give the same bytes: fixed key order, no timestamps, input order kept.
+- **JSON file** is an array with one object per invoice; each object carries `"schema": "voiced.invoice.v1"`.
+- Cancelled invoices are included with `"cancelled": true` (their figures are kept; filter them out of sums).
+- An unregistered supplier's plain "Invoice" has `document_type: "invoice"`, all tax heads zero and no supplier GSTIN.
+
+## Invoice object
+
+| Key | Meaning |
+| --- | --- |
+| `schema`, `number`, `issue_date`, `due_date` | `YYYY-MM-DD` dates; `due_date` is null when unset |
+| `document_type` | `tax_invoice` or `invoice` |
+| `status`, `cancelled`, `cancelled_at`, `cancel_reason` | `status` is `issued` or `cancelled` |
+| `currency`, `po_number` | always `INR` |
+| `supplier` | `name`, `address`, `gstin` (null if none), `pan`, `gst_registration`, `state {code, name}`; frozen at issue |
+| `client` | `name`, `gstin`, `gst_category`, `address {text, line1, line2, city, pincode, state}`, `place_of_supply {code, name}` |
+| `items[]` | `line`, `description`, `hsn_sac`, `quantity` (decimal string), `unit`, `rate`, `taxable_value` (each with `_paise`) |
+| `tax` | `cgst`, `sgst`, `utgst`, `igst`, each `{rate, amount_paise, amount}`; heads that do not apply are zero |
+| `totals` | `subtotal`, `discount`, `taxable_value`, `tax`, `total` (each with `_paise`), `amount_in_words` |
+| `reverse_charge`, `notes` | |
+| `payments[]` | `date`, `amount` (cash), `tds`, `mode`, `reference` (amounts with `_paise`) |
+
+Notes on the fields:
+
+- **Items.** `taxable_value` of a line is the line amount before the invoice-level discount. `totals.taxable_value` is
+  `subtotal - discount`, the base the tax is charged on. A fixed-amount line has `quantity "1"` and `unit null`.
+- **UTGST.** When the supplier is in a union territory without a legislature (state codes 04, 26, 31, 35, 38) the second
+  head is reported under `utgst` and `sgst` is zero.
+- **Client details.** The name, GSTIN, printed address and place of supply are frozen on the invoice. The structured
+  address parts and `gst_category` come from the client's saved record at export time (null or derived from the GSTIN
+  when the invoice has no saved client).
+- **Supplier snapshot.** Only name, address, GSTIN, PAN, registration and state are exported; logo paths, e-mail and
+  phone are not.
+
+## Line-items CSV
+
+One row per line item, UTF-8 with a byte order mark and CRLF line ends; text cells that a spreadsheet would read as a
+formula get a leading apostrophe. Columns: `invoice_number, issue_date, due_date, document_type, status, cancelled,
+currency, supplier_name, supplier_gstin, client_name, client_gstin, client_gst_category, place_of_supply_code,
+place_of_supply, reverse_charge, line, description, hsn_sac, quantity, unit, rate, taxable_value, invoice_discount,
+invoice_cgst, invoice_sgst, invoice_utgst, invoice_igst, invoice_total`. The `invoice_*` amounts are filled on the first
+row of each invoice only, so summing a column never counts an invoice twice.

scripts/erpnext-e2e/Containerfile.ic

@@ -0,0 +1,5 @@
+# frappe/erpnext v15 plus the india_compliance app (installed per site, not globally)
+FROM docker.io/frappe/erpnext:v15.121.6
+USER frappe
+RUN bench get-app --skip-assets --branch version-15 https://github.com/resilient-tech/india-compliance.git \
+ && ls -1 apps > sites/apps.txt || true

scripts/erpnext-e2e/README.md

@@ -0,0 +1,148 @@
+# ERPNext live end-to-end (podman)
+
+Runs Voiced's ERPNext integration against real ERPNext v15 sites: one plain site and one with India Compliance.
+Everything is rootless podman (`podman` and `podman-compose`, never docker). All names are prefixed `voiced-erp`.
+
+| File | Purpose |
+|---|---|
+| `compose.yml` | Lean stack: MariaDB, one Redis, backend (gunicorn on `127.0.0.1:8088`), one worker. Project name `voiced-erp`. |
+| `Containerfile.ic` | `frappe/erpnext:v15.121.6` plus the `india_compliance` app files (`version-15` branch). |
+| `setup.sh` | Builds the image, starts the stack, creates both sites, prepares them, writes `.env.a` and `.env.b`. |
+| `setup_site.py` | Runs inside the container: company, accounts, address, items, integration user and keys. |
+| `../../src-tauri/src/integrations/erpnext/live_tests.rs` | The `#[ignore]` Rust tests. |
+
+## Reproduce
+
+```bash
+cd scripts/erpnext-e2e
+./setup.sh            # first run pulls ~2 GB of images and takes about 10 minutes
+```
+
+`setup.sh` creates two sites that one backend serves by Host header:
+
+| Site | URL | Contents | Env file |
+|---|---|---|---|
+| `127.0.0.1` | `http://127.0.0.1:8088` | ERPNext only | `.env.a` |
+| `localhost` | `http://localhost:8088` | ERPNext + India Compliance | `.env.b` |
+
+Both get the company "Voiced Test Co" (abbreviation `VTC`, INR, India, fiscal year 2026-27), the output tax accounts
+`Output Tax CGST|SGST|UTGST|IGST - VTC` (India Compliance creates its own with the same names), `TDS Receivable - VTC`,
+the bank account `HDFC - VTC`, a company address, the UOMs Hour/Minute/Second, the items `VOICED-SERVICE` (stock UOM Nos)
+and `VOICED-HOURLY` (stock UOM Hour), and an integration user with a fresh API key and secret.
+`.env.*` files hold those keys; they are git-ignored (`.env.*` in the root `.gitignore`) and must never be committed.
+
+Run the Rust tests (they only touch the site named by the sourced env file):
+
+```bash
+set -a; . scripts/erpnext-e2e/.env.a; set +a      # or .env.b for the India Compliance site
+cargo test --manifest-path src-tauri/Cargo.toml live_ -- --ignored --test-threads=1
+```
+
+Environment variables the tests read:
+
+| Variable | Meaning |
+|---|---|
+| `ERPNEXT_URL`, `ERPNEXT_KEY`, `ERPNEXT_SECRET` | Site address and the integration user's API key and secret. |
+| `ERPNEXT_COMPANY` (`Voiced Test Co`), `ERPNEXT_ABBR` (`VTC`) | Company; account names derive from the abbreviation. |
+| `ERPNEXT_IC` | `1` on the India Compliance site; the `live_ic_*` tests skip themselves otherwise. |
+| `ERPNEXT_ROUNDING` | `banker` (ERPNext default) or `commercial`; decides what the half-paise test expects. |
+| `ERPNEXT_BANK_ACCOUNT` (`HDFC - VTC`) | Account that receives payments. |
+
+Each test builds its own in-memory Voiced database and a fresh invoice series (`L<time><n>/001`), so reruns never collide
+with documents from earlier runs. Switch the rounding method of a site with
+`podman exec -i voiced-erp-backend bash -c "cd /home/frappe/frappe-bench/sites && /home/frappe/frappe-bench/env/bin/python - 127.0.0.1 rounding=commercial" < setup_site.py`
+(re-run `setup.sh` or copy the printed `ERPNEXT_*` lines if you need the new key; the key is regenerated on every run).
+
+Tear down (touches only the `voiced-erp` project; the cached images stay):
+
+```bash
+podman-compose -p voiced-erp -f compose.yml down -v
+podman volume rm voiced-erp_voiced-erp-db voiced-erp_voiced-erp-sites voiced-erp_voiced-erp-logs   # only if `down -v` left them
+```
+
+Notes on rootless podman: the compose file has no healthchecks (podman's healthcheck timers need systemd), and the
+backend and worker are started by `setup.sh` after the configurator has exited.
+
+## Integration user (feeds the main README)
+
+Create a dedicated user in ERPNext (User list, type System User) with **the roles "Accounts User" and "Sales User"**.
+Then open the user, "Settings" tab, "API Access", "Generate Keys", and copy the secret once.
+
+Why both (verified live on plain ERPNext and with India Compliance; `setup_site.py` creates exactly this user):
+
+- "Accounts User": create and submit Sales Invoices (draft, insert-and-submit, submit-later) and Payment Entries; read
+  Accounts, Items, UOMs, Cost Centers, Price Lists, Item Groups, Company, the Sales Invoice naming series and (with
+  India Compliance) GST Settings; attach a private PDF to the invoice.
+- "Sales User": look up and create Customers and Addresses, read Customer Groups, Territories and the tax templates.
+  With "Accounts User" alone a fresh site answers HTTP 403 on Customer.
+
+No tax template is used (Voiced always sends explicit tax rows), so the tax-template list is only a convenience.
+Do not use Administrator or System Manager keys. Roles on a user are cached by Frappe: after changing them run
+`bench clear-cache` or the next request may still use the old set.
+
+## Results (what was verified live)
+
+Versions: Frappe 15.121.3, ERPNext 15.121.6, India Compliance 15.32.0 (the `version-15` branch; commit `db73b3e` at the time of this run, so a later image build may differ), MariaDB 11.8,
+Redis 8.6, API v2 naming available (Frappe 15.73 or newer).
+
+Verified on both sites unless marked IC (India Compliance site only):
+
+- Connection test: user, frappe/erpnext/india_compliance versions, India Compliance detection, no warnings when the
+  accounts match. Option lists load (companies, addresses, accounts, UOMs, cost centers, groups, series).
+- Sales Invoice push in mirror mode (API v2, `name` = Voiced number): CGST+SGST, IGST, discount (`apply_discount_on:
+  Net Total`), fractional hours, repeated descriptions on code-less rows, item-code rows from a preset, remarks. The
+  grand total, the tax amounts per head and the posting date equal Voiced's; `disable_rounded_total` works.
+- PDF attachment: uploaded through `upload_file`, `is_private` is 1.
+- Idempotency: a second push is a no-op; with the local sync row deleted, the 409 path adopts the existing document
+  (no duplicate, no second PDF).
+- Submit: insert then submit in a second push (v2 `method/submit`), and series mode through the v1 `run_method` route.
+- Series mode: ERPNext names the document, the Voiced number is in `remarks`, and a lost sync row is recovered by the
+  remarks lookup.
+- Payments: `get_payment_entry` plus overrides. `bank_account` is the Account name and lands in `paid_to`;
+  `paid_amount = received_amount = cash`; the reference's `allocated_amount = cash + TDS`; TDS is one `deductions` row
+  `{account, cost_center, amount: +TDS}`; the invoice's outstanding falls by cash + TDS; partial payments leave the rest.
+- Customer and Address shape (IC: `gstin`, `gst_category` on both; state exact name; link to the Customer).
+- IC: `place_of_supply` as `29-Karnataka`; Voiced's 38 state names equal India Compliance's `gst_state` list; HSN/SAC
+  must be 6 or 8 digits (GST Settings `min_hsn_digits` was 6) and is enforced at submit; the 16-character name rule;
+  GST-account warnings (mismatching CGST account, company without GST accounts, a too-long next number).
+
+Defects found and fixed (each has a mock-based test in the normal suite):
+
+1. `load_options`: the company-address list asked for the India Compliance-only `gstin` field and failed with HTTP 417
+   on a plain site. It now retries without it.
+2. Code-less rows with a fractional quantity of hours/minutes failed ("Quantity cannot be a fraction ... UOM Nos"):
+   ERPNext defaults the row's stock UOM to Nos without an item. Such rows now also send `stock_uom` = the row UOM.
+3. Rounding: ERPNext's default Rounding Method is Banker's Rounding; Voiced rounds half-paise up. On ties (for example
+   9% of 10.50) the totals differ by 1 paise. A created document whose total differs is now a `conflict`: kept as a
+   draft, never submitted, no PDF, with a message naming the fix (System Settings, Rounding Method, "Commercial
+   Rounding"). The existing-document conflict message carries the same hint. With Commercial Rounding every case matched.
+4. A lost link to a client's address created a new address on every first push. The customer's matching address (same
+   first line and PIN) is reused. (`creation` in the order-by is ambiguous with a Dynamic Link filter and gives HTTP 500.)
+5. A re-adopted document got a second copy of the PDF. A file of the same name is now looked up first.
+6. IC refuses `is_reverse_charge = 1` unless the tax rows are negative amounts on separate "RCM" accounts, which would
+   make ERPNext's total differ from Voiced's. It is sent as 0 and the push warns.
+7. IC's 16-character rule is now checked before the POST in mirror mode (a readable, local refusal that points to series
+   naming); ERPNext's own message is "Transaction Name must be 16 characters or fewer to meet GST requirements".
+8. A TDS-only payment (no cash) got ERPNext's bare "Paid Amount is mandatory"; it is refused locally with the reason.
+9. A fractional quantity on a whole-number UOM is refused by ERPNext with a readable message; Voiced appends what to
+   change (unit mapping). No local pre-check: whether "Nos" is whole-number is a site setting.
+
+Limits and notes:
+
+- Rounding setting cannot be read by a restricted user, so it is detected by comparing the totals after creating the
+  draft, not in the connection test.
+- With India Compliance, an invoice with a missing or short HSN/SAC is created as a draft and fails at submit; the
+  readable ERPNext message ("HSN/SAC must exist and should be 6 or 8 digits long for the following row numbers") is
+  shown.
+- A mirrored item row with an item code whose stock UOM differs from the row UOM works for whole quantities
+  (`conversion_factor` 1); a fractional quantity needs the item's stock UOM to allow fractions.
+- One intermittent failure was seen once in the half-paise test on the India Compliance site (the push of a non-tie
+  case failed; three later full runs and a single-test run passed). The cause was not captured.
+
+Not verified:
+
+- ERPNext v14 and v16 (the v16 images that exist on some machines were not used), other India Compliance versions.
+- Windows and WebView2; the Tauri commands and UI (the tests call the Rust push/payment functions directly).
+- Overseas/SEZ customers, UTGST supplier states, multi-currency, GST Settings with "Round Off GST Values" on,
+  reverse charge booked on RCM accounts, e-invoice/e-waybill (India Compliance API features), a TLS or reverse-proxied
+  site (only plain `http://` on a loopback address), Frappe Cloud or any site with `allow_cors` or rate limits.

scripts/erpnext-e2e/compose.yml

@@ -0,0 +1,66 @@
+# Lean ERPNext v15 stack for Voiced's live integration tests (project name: voiced-erp).
+# db + redis + backend (gunicorn, published on 127.0.0.1:8088) + one worker. No nginx/websocket/scheduler.
+# setup.sh starts it in order (db, redis, configurator, then backend and worker); do not `up` it blindly.
+# Image: voiced-erp-ic:v15 = frappe/erpnext v15 + the india_compliance app files (see Containerfile.ic).
+name: voiced-erp
+services:
+  db:
+    image: docker.io/library/mariadb:11.8
+    container_name: voiced-erp-db
+    command:
+      - --character-set-server=utf8mb4
+      - --collation-server=utf8mb4_unicode_ci
+      - --skip-character-set-client-handshake
+      - --innodb-buffer-pool-size=256M
+    environment:
+      MARIADB_ROOT_PASSWORD: admin
+    volumes:
+      - voiced-erp-db:/var/lib/mysql
+
+  redis:
+    image: docker.io/library/redis:8.6-alpine
+    container_name: voiced-erp-redis
+
+  configurator:
+    image: localhost/voiced-erp-ic:v15
+    container_name: voiced-erp-configurator
+    restart: "no"
+    entrypoint: ["bash", "-c"]
+    command:
+      - >
+        wait-for-it -t 120 db:3306;
+        ls -1 apps > sites/apps.txt;
+        bench set-config -g db_host db;
+        bench set-config -gp db_port 3306;
+        bench set-config -g redis_cache redis://redis:6379;
+        bench set-config -g redis_queue redis://redis:6379;
+        bench set-config -g redis_socketio redis://redis:6379;
+        bench set-config -gp socketio_port 9000;
+    volumes:
+      - voiced-erp-sites:/home/frappe/frappe-bench/sites
+      - voiced-erp-logs:/home/frappe/frappe-bench/logs
+    depends_on:
+      - db
+      - redis
+
+  backend:
+    image: localhost/voiced-erp-ic:v15
+    container_name: voiced-erp-backend
+    ports:
+      - "127.0.0.1:8088:8000"
+    volumes:
+      - voiced-erp-sites:/home/frappe/frappe-bench/sites
+      - voiced-erp-logs:/home/frappe/frappe-bench/logs
+
+  worker:
+    image: localhost/voiced-erp-ic:v15
+    container_name: voiced-erp-worker
+    command: ["bench", "worker", "--queue", "short,default,long"]
+    volumes:
+      - voiced-erp-sites:/home/frappe/frappe-bench/sites
+      - voiced-erp-logs:/home/frappe/frappe-bench/logs
+
+volumes:
+  voiced-erp-db:
+  voiced-erp-sites:
+  voiced-erp-logs:

scripts/erpnext-e2e/setup.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+# Brings up the voiced-erp podman project and prepares two ERPNext v15 sites for the live tests:
+#   127.0.0.1  plain ERPNext            -> .env.a   (URL http://127.0.0.1:8088)
+#   localhost  ERPNext + India Compliance -> .env.b (URL http://localhost:8088)
+# Both are served by the same backend; Frappe picks the site from the Host header.
+# Safe to re-run: existing sites are kept and the integration user's key is regenerated.
+set -euo pipefail
+cd "$(dirname "$0")"
+
+COMPOSE=(podman-compose -p voiced-erp -f compose.yml)
+IMAGE=localhost/voiced-erp-ic:v15
+BENCH_SITES=/home/frappe/frappe-bench/sites
+
+podman image exists "$IMAGE" || podman build -t "$IMAGE" -f Containerfile.ic .
+
+"${COMPOSE[@]}" up -d db redis configurator
+until [ "$(podman inspect -f '{{.State.Status}}' voiced-erp-configurator)" = exited ]; do sleep 2; done
+[ "$(podman inspect -f '{{.State.ExitCode}}' voiced-erp-configurator)" = 0 ] || { echo "configurator failed: podman logs voiced-erp-configurator" >&2; exit 1; }
+"${COMPOSE[@]}" up -d backend worker
+
+in_backend() { podman exec -i voiced-erp-backend bash -c "$1"; }
+
+for site in 127.0.0.1 localhost; do
+  default=""; [ "$site" = 127.0.0.1 ] && default="--set-default"
+  in_backend "test -d $BENCH_SITES/$site || bench new-site $site --mariadb-user-host-login-scope='%' \
+    --admin-password=admin --db-root-username=root --db-root-password=admin --install-app erpnext $default" >/dev/null
+done
+
+until curl -fsS http://127.0.0.1:8088/api/method/ping >/dev/null 2>&1; do sleep 2; done
+
+# setup_site.py prints `ENV KEY=VALUE` lines; turn them into a sourceable env file (untracked: .env.* is ignored).
+write_env() { # site, url, file, extra args...
+  local site=$1 url=$2 file=$3; shift 3
+  in_backend "cd $BENCH_SITES && /home/frappe/frappe-bench/env/bin/python - $site $*" < setup_site.py \
+    | sed -n 's/^ENV \([A-Z_]*\)=\(.*\)$/export \1="\2"/p' > "$file"
+  echo "export ERPNEXT_URL=\"$url\"" >> "$file"
+  chmod 600 "$file"
+}
+write_env 127.0.0.1 http://127.0.0.1:8088 .env.a
+write_env localhost http://localhost:8088 .env.b ic
+
+echo "Ready. Source .env.a (plain) or .env.b (India Compliance), then run the live tests (see README.md)."

scripts/erpnext-e2e/setup_site.py

@@ -0,0 +1,197 @@
+"""Prepare one ERPNext site for Voiced's live integration tests.
+
+Run inside the backend container (see README.md):
+    podman exec -i voiced-erp-backend python - <site> [ic] [rounding=commercial] < setup_site.py
+
+Creates (idempotently): the Indian company "Voiced Test Co" (abbr VTC, INR), the fiscal year, GST output tax
+accounts, a bank account, a company address, an integration user with API keys, and a few Items/UOMs.
+Prints one line `ENV KEY=VALUE` per value the Rust live tests need. Never run against a real site.
+"""
+import json
+import sys
+import time
+
+import frappe
+
+SITE = sys.argv[1]
+IC = "ic" in sys.argv[2:]
+# `rounding=commercial` switches System Settings > Rounding Method (the ERPNext default is Banker's Rounding).
+ROUNDING = {"commercial": "Commercial Rounding", "banker": "Banker's Rounding"}.get(
+    next((a.split("=", 1)[1] for a in sys.argv[2:] if a.startswith("rounding=")), ""), None
+)
+ABBR = "VTC"
+COMPANY = "Voiced Test Co"
+
+frappe.init(site=SITE, sites_path="/home/frappe/frappe-bench/sites")
+frappe.connect()
+frappe.set_user("Administrator")
+
+
+def out(key, value):
+    print(f"ENV {key}={value}")
+
+
+def exists(doctype, name):
+    return bool(frappe.db.exists(doctype, name))
+
+
+def insert(doc):
+    d = frappe.get_doc(doc)
+    d.insert(ignore_permissions=True)
+    frappe.db.commit()
+    return d
+
+
+# ---- 1. site, optionally India Compliance (before the wizard so it can add its own accounts) ----
+if IC and "india_compliance" not in frappe.get_installed_apps():
+    from frappe.installer import install_app
+
+    install_app("india_compliance", verbose=False)
+    frappe.db.commit()
+
+# ---- 2. setup wizard ----
+if not frappe.db.get_single_value("System Settings", "setup_complete"):
+    from frappe.desk.page.setup_wizard.setup_wizard import setup_complete
+
+    setup_complete(
+        {
+            "language": "English",
+            "country": "India",
+            "timezone": "Asia/Kolkata",
+            "currency": "INR",
+            "full_name": "Voiced Admin",
+            "email": "admin@voiced.test",
+            "password": "admin",
+            "company_name": COMPANY,
+            "company_abbr": ABBR,
+            "domains": ["Services"],
+            "chart_of_accounts": "Standard",
+            "fy_start_date": "2026-04-01",
+            "fy_end_date": "2027-03-31",
+            "bank_account": "HDFC",
+            "setup_demo": 0,
+        }
+    )
+    # setup_complete may run its stages on a worker; wait for it.
+    for _ in range(120):
+        frappe.db.rollback()
+        if frappe.db.get_single_value("System Settings", "setup_complete") and exists("Company", COMPANY):
+            break
+        time.sleep(2)
+    frappe.clear_cache()
+    frappe.db.commit()
+assert exists("Company", COMPANY), "setup wizard did not create the company"
+
+# ---- 3. accounts ----
+duties = frappe.db.get_value("Account", {"company": COMPANY, "account_name": "Duties and Taxes", "is_group": 1}, "name")
+assert duties, "Duties and Taxes group not found"
+for head in ("CGST", "SGST", "UTGST", "IGST"):
+    name = f"Output Tax {head} - {ABBR}"
+    if not exists("Account", name):
+        insert(
+            {
+                "doctype": "Account",
+                "account_name": f"Output Tax {head}",
+                "parent_account": duties,
+                "company": COMPANY,
+                "account_type": "Tax",
+                "root_type": "Liability",
+                "is_group": 0,
+            }
+        )
+tds = f"TDS Receivable - {ABBR}"
+if not exists("Account", tds):
+    parent = frappe.db.get_value("Account", {"company": COMPANY, "account_name": "Current Assets", "is_group": 1}, "name")
+    insert(
+        {
+            "doctype": "Account",
+            "account_name": "TDS Receivable",
+            "parent_account": parent,
+            "company": COMPANY,
+            "account_type": "Tax",
+            "root_type": "Asset",
+            "is_group": 0,
+        }
+    )
+
+# ---- 4. company address (India Compliance needs one with a GSTIN-ish state) ----
+addr_name = f"{COMPANY}-Billing"
+if not exists("Address", addr_name):
+    d = {
+        "doctype": "Address",
+        "address_title": COMPANY,
+        "address_type": "Billing",
+        "address_line1": "1 Test Street",
+        "city": "Mumbai",
+        "state": "Maharashtra",
+        "pincode": "400001",
+        "country": "India",
+        "links": [{"link_doctype": "Company", "link_name": COMPANY}],
+    }
+    if IC:
+        d["gst_category"] = "Registered Regular"
+        d["gstin"] = "27AAPFU0939F1ZV"
+    insert(d)
+
+# ---- 5. items / UOMs ----
+for uom in ("Hour", "Minute", "Second"):
+    if not exists("UOM", uom):
+        insert({"doctype": "UOM", "uom_name": uom})
+for code, uom in (("VOICED-SERVICE", "Nos"), ("VOICED-HOURLY", "Hour")):
+    if not exists("Item", code):
+        d = {
+            "doctype": "Item",
+            "item_code": code,
+            "item_name": code,
+            "item_group": "Services",
+            "stock_uom": uom,
+            "is_stock_item": 0,
+        }
+        if IC:
+            d["gst_hsn_code"] = "998314"
+        insert(d)
+
+# ---- 5b. rounding method ----
+if ROUNDING:
+    frappe.db.set_single_value("System Settings", "rounding_method", ROUNDING)
+    frappe.db.commit()
+    frappe.clear_cache()
+
+# ---- 6. integration user ----
+USER = f"voiced-integration@{SITE.replace('.', '-')}.test"
+# The role set that was verified live (with and without India Compliance): "Accounts User" creates and submits Sales
+# Invoices and Payment Entries and reads the accounting masters; "Sales User" adds the Customer and Address rights
+# (look up, create) and the tax-template list. Accounts User alone gets HTTP 403 on Customer.
+ROLES = ["Accounts User", "Sales User"]
+if not exists("User", USER):
+    insert(
+        {
+            "doctype": "User",
+            "email": USER,
+            "first_name": "Voiced",
+            "last_name": "Integration",
+            "send_welcome_email": 0,
+            "user_type": "System User",
+            "roles": [{"role": r} for r in ROLES],
+        }
+    )
+user = frappe.get_doc("User", USER)
+user.set("roles", [{"role": r} for r in ROLES])
+secret = frappe.generate_hash(length=32)
+if not user.api_key:
+    user.api_key = frappe.generate_hash(length=15)
+user.api_secret = secret
+user.save(ignore_permissions=True)
+frappe.db.commit()
+frappe.clear_cache(user=USER)
+frappe.clear_cache()
+
+out("ERPNEXT_KEY", user.api_key)
+out("ERPNEXT_SECRET", secret)
+out("ERPNEXT_COMPANY", COMPANY)
+out("ERPNEXT_ABBR", ABBR)
+out("ERPNEXT_IC", "1" if IC else "0")
+out("ERPNEXT_USER", USER)
+out("ERPNEXT_ROUNDING", "commercial" if frappe.db.get_single_value("System Settings", "rounding_method") == "Commercial Rounding" else "banker")
+print(json.dumps({"roles": ROLES}))
+frappe.destroy()

src-tauri/Cargo.lock

@@ -509,6 +509,16 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "core-foundation"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91e195e091a93c46f7102ec7818a2aa394e1e1771c3ab4825963fa03e45afb8f"
+dependencies = [
+ "core-foundation-sys",
+ "libc",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.10.1"
@@ -532,7 +542,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "064badf302c3194842cf2c5d61f56cc88e54a759313879cdf03abdd27d0c3b97"
 dependencies = [
  "bitflags 2.13.2",
- "core-foundation",
+ "core-foundation 0.10.1",
  "core-graphics-types",
  "foreign-types",
  "libc",
@@ -545,10 +555,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d44a101f213f6c4cdc1853d4b78aef6db6bdfa3468798cc1d9912f4735013eb"
 dependencies = [
  "bitflags 2.13.2",
- "core-foundation",
+ "core-foundation 0.10.1",
  "libc",
 ]
 
+[[package]]
+name = "core_detect"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f8f80099a98041a3d1622845c271458a2d73e688351bf3cb999266764b81d48"
+
 [[package]]
 name = "cpufeatures"
 version = "0.2.17"
@@ -875,6 +891,20 @@ version = "1.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4ef6b89e5b37196644d8796de5268852ff179b44e96276cf4290264843743bb7"
 
+[[package]]
+name = "encoding_rs"
+version = "0.8.42"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e985e0451871ad22fb8d2b6b076e2028a502a0d3950998c2c5c0a4f9b5d9679"
+dependencies = [
+ "cfg-if",
+ "core_detect",
+ "multiversion_no_op",
+ "rustversion",
+ "scopeguard",
+ "simdutf8",
+]
+
 [[package]]
 name = "endi"
 version = "1.1.1"
@@ -1244,6 +1274,17 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff2abc00be7fca6ebc474524697ae276ad847ad0a6b3faa4bcb027e9a4614ad0"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.3.4"
@@ -1415,6 +1456,25 @@ dependencies = [
  "syn 2.0.119",
 ]
 
+[[package]]
+name = "h2"
+version = "0.4.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ef8e5e5a340588f4452631496976cf8636d4a7ecf600239fdc27615d2530bc16"
+dependencies = [
+ "atomic-waker",
+ "bytes",
+ "fnv",
+ "futures-core",
+ "futures-sink",
+ "http",
+ "indexmap 2.14.2",
+ "slab",
+ "tokio",
+ "tokio-util",
+ "tracing",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -1531,6 +1591,7 @@ dependencies = [
  "bytes",
  "futures-channel",
  "futures-core",
+ "h2",
  "http",
  "http-body",
  "httparse",
@@ -1541,6 +1602,21 @@ dependencies = [
  "want",
 ]
 
+[[package]]
+name = "hyper-rustls"
+version = "0.27.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfa8e654703247911e29c23fbeaa261834bd9bb74efba2f9acddc37bfb127f53"
+dependencies = [
+ "http",
+ "hyper",
+ "hyper-util",
+ "rustls",
+ "tokio",
+ "tokio-rustls",
+ "tower-service",
+]
+
 [[package]]
 name = "hyper-util"
 version = "0.1.21"
@@ -1560,9 +1636,11 @@ dependencies = [
  "percent-encoding",
  "pin-project-lite",
  "socket2",
+ "system-configuration",
  "tokio",
  "tower-service",
  "tracing",
+ "windows-registry",
 ]
 
 [[package]]
@@ -1891,6 +1969,36 @@ dependencies = [
  "windows-sys 0.45.0",
 ]
 
+[[package]]
+name = "jni"
+version = "0.22.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5efd9a482cf3a427f00d6b35f14332adc7902ce91efb778580e180ff90fa3498"
+dependencies = [
+ "cfg-if",
+ "combine",
+ "jni-macros",
+ "jni-sys 0.4.1",
+ "log",
+ "simd_cesu8",
+ "thiserror 2.0.21",
+ "walkdir",
+ "windows-link",
+]
+
+[[package]]
+name = "jni-macros"
+version = "0.22.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a00109accc170f0bdb141fed3e393c565b6f5e072365c3bd58f5b062591560a3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "rustc_version",
+ "simd_cesu8",
+ "syn 2.0.119",
+]
+
 [[package]]
 name = "jni-sys"
 version = "0.3.1"
@@ -2090,6 +2198,16 @@ version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
 
+[[package]]
+name = "mime_guess"
+version = "2.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7c44f8e672c00fe5308fa235f821cb4198414e1c77935c1ab6948d3fd78550e"
+dependencies = [
+ "mime",
+ "unicase",
+]
+
 [[package]]
 name = "miniz_oxide"
 version = "0.8.9"
@@ -2152,6 +2270,12 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "multiversion_no_op"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "743fb55ba31b18fb1ecef6bdc9aa2743314978ac084044301a7eee33fb99a20d"
+
 [[package]]
 name = "ndk"
 version = "0.9.0"
@@ -2439,6 +2563,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "openssl-probe"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c87def4c32ab89d880effc9e097653c8da5d6ef28e6b539d313baaacfbafcbe"
+
 [[package]]
 name = "option-ext"
 version = "0.2.0"
@@ -2866,21 +2996,31 @@ checksum = "16a1cfa75cc186dd73d5818e510e042e40927bccc9c236b061cea97e1eb08029"
 dependencies = [
  "base64 0.23.1",
  "bytes",
+ "encoding_rs",
  "futures-core",
  "futures-util",
+ "h2",
  "http",
  "http-body",
  "http-body-util",
  "hyper",
+ "hyper-rustls",
  "hyper-util",
  "js-sys",
  "log",
+ "mime",
+ "mime_guess",
  "percent-encoding",
  "pin-project-lite",
+ "rustls",
+ "rustls-pki-types",
+ "rustls-platform-verifier",
  "serde",
  "serde_json",
+ "serde_urlencoded",
  "sync_wrapper",
  "tokio",
+ "tokio-rustls",
  "tokio-util",
  "tower",
  "tower-http",
@@ -2916,6 +3056,20 @@ dependencies = [
  "windows-sys 0.60.2",
 ]
 
+[[package]]
+name = "ring"
+version = "0.17.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4689e6c2294d81e88dc6261c768b63bc4fcdb852be6d1352498b114f61383b7"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "getrandom 0.2.17",
+ "libc",
+ "untrusted",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "rsqlite-vfs"
 version = "0.1.1"
@@ -2979,12 +3133,91 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "rustls"
+version = "0.23.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d41d731c7d2f962d1ccc364cec258de3c0e93b38c2fb3ba97ac74513048d634"
+dependencies = [
+ "once_cell",
+ "ring",
+ "rustls-pki-types",
+ "rustls-webpki",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-native-certs"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dab5152771c58876a2146916e53e35057e1a4dfa2b9df0f0305b07f611fdea4d"
+dependencies = [
+ "openssl-probe",
+ "rustls-pki-types",
+ "schannel",
+ "security-framework",
+]
+
+[[package]]
+name = "rustls-pki-types"
+version = "1.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2f4925028c7eb5d1fcdaf196971378ed9d2c1c4efc7dc5d011256f76c99c0a96"
+dependencies = [
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-platform-verifier"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1167586491e2b18b8bfbb293e8180ec17c201c4f076d7cb3070ca964e7598f98"
+dependencies = [
+ "core-foundation 0.10.1",
+ "core-foundation-sys",
+ "jni 0.22.4",
+ "log",
+ "once_cell",
+ "rustls",
+ "rustls-native-certs",
+ "rustls-platform-verifier-android",
+ "rustls-webpki",
+ "security-framework",
+ "security-framework-sys",
+ "webpki-root-certs",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "rustls-platform-verifier-android"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eec689c0bc40ff2458a5977b6619cb718087084a18e02a131c599b62d05e1a5f"
+
+[[package]]
+name = "rustls-webpki"
+version = "0.103.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3c3cf1d8b1e7d4927e2d154c3fcb02979afb9939629c62cd9048d4f07b60ac2"
+dependencies = [
+ "ring",
+ "rustls-pki-types",
+ "untrusted",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf54715a573b99ac80df0bc206da022bcd442c974952c7b9720069370852e21f"
 
+[[package]]
+name = "ryu"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9774ba4a74de5f7b1c1451ed6cd5285a32eddb5cccb8cc655a4e50009e06477f"
+
 [[package]]
 name = "same-file"
 version = "1.0.6"
@@ -2994,6 +3227,15 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "schannel"
+version = "0.1.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91c1b7e4904c873ef0710c1f407dde2e6287de2bebc1bbbf7d430bb7cbffd939"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "schemars"
 version = "0.8.22"
@@ -3051,6 +3293,29 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
+[[package]]
+name = "security-framework"
+version = "3.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b7f4bc775c73d9a02cde8bf7b2ec4c9d12743edf609006c7facc23998404cd1d"
+dependencies = [
+ "bitflags 2.13.2",
+ "core-foundation 0.10.1",
+ "core-foundation-sys",
+ "libc",
+ "security-framework-sys",
+]
+
+[[package]]
+name = "security-framework-sys"
+version = "2.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ce2691df843ecc5d231c0b14ece2acc3efb62c0a398c7e1d875f3983ce020e3"
+dependencies = [
+ "core-foundation-sys",
+ "libc",
+]
+
 [[package]]
 name = "selectors"
 version = "0.38.0"
@@ -3175,6 +3440,18 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "serde_urlencoded"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3491c14715ca2294c4d6a88f15e84739788c1d030eed8c110436aafdaa2f3fd"
+dependencies = [
+ "form_urlencoded",
+ "itoa",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "serde_with"
 version = "3.24.0"
@@ -3272,6 +3549,22 @@ version = "0.3.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3a219298ac11a56ea9a6d2120044824d6f01aeb034955e7af7bc16858527deea"
 
+[[package]]
+name = "simd_cesu8"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "11031e251abf8611c80f460e19dbdeb54a66db918e49c65a7065b46ac7aec520"
+dependencies = [
+ "rustc_version",
+ "simdutf8",
+]
+
+[[package]]
+name = "simdutf8"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
+
 [[package]]
 name = "siphasher"
 version = "1.0.4"
@@ -3396,6 +3689,12 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
+[[package]]
+name = "subtle"
+version = "2.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
+
 [[package]]
 name = "swift-rs"
 version = "1.0.8"
@@ -3459,6 +3758,27 @@ dependencies = [
  "syn 3.0.6",
 ]
 
+[[package]]
+name = "system-configuration"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a13f3d0daba03132c0aa9767f98351b3488edc2c100cda2d2ec2b04f3d8d3c8b"
+dependencies = [
+ "bitflags 2.13.2",
+ "core-foundation 0.9.4",
+ "system-configuration-sys",
+]
+
+[[package]]
+name = "system-configuration-sys"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e1d1b10ced5ca923a1fcb8d03e96b8d3268065d724548c0211415ff6ac6bac4"
+dependencies = [
+ "core-foundation-sys",
+ "libc",
+]
+
 [[package]]
 name = "system-deps"
 version = "6.2.2"
@@ -3480,7 +3800,7 @@ checksum = "f37f381f4e048e6cdf038b5705f8cf14ad108279d46eb968140a7b291aba9400"
 dependencies = [
  "bitflags 2.13.2",
  "block2",
- "core-foundation",
+ "core-foundation 0.10.1",
  "core-graphics",
  "crossbeam-channel",
  "dbus",
@@ -3490,7 +3810,7 @@ dependencies = [
  "gdkwayland-sys",
  "gdkx11-sys",
  "gtk",
- "jni",
+ "jni 0.21.1",
  "libc",
  "log",
  "ndk",
@@ -3546,7 +3866,7 @@ dependencies = [
  "gtk",
  "heck 0.5.0",
  "http",
- "jni",
+ "jni 0.21.1",
  "libc",
  "log",
  "mime",
@@ -3763,7 +4083,7 @@ dependencies = [
  "dpi",
  "gtk",
  "http",
- "jni",
+ "jni 0.21.1",
  "objc2",
  "objc2-ui-kit",
  "objc2-web-kit",
@@ -3786,7 +4106,7 @@ checksum = "7f9e7e0c9f80a5130773cfabb6df4dc924518fb1b2c923726966804634b57d22"
 dependencies = [
  "gtk",
  "http",
- "jni",
+ "jni 0.21.1",
  "log",
  "objc2",
  "objc2-app-kit",
@@ -3972,9 +4292,31 @@ dependencies = [
  "mio",
  "pin-project-lite",
  "socket2",
+ "tokio-macros",
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "tokio-macros"
+version = "2.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78773a2a397f451582ce068015985c33193cf6dea8b74d2a639fe457b2f07b0e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 3.0.6",
+]
+
+[[package]]
+name = "tokio-rustls"
+version = "0.26.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9cc2678c2cdd569ef8215e2afd7954ada2ae20b4fdd2c5fe6139a3b02d105db"
+dependencies = [
+ "rustls",
+ "tokio",
+]
+
 [[package]]
 name = "tokio-util"
 version = "0.7.19"
@@ -3984,6 +4326,7 @@ dependencies = [
  "bytes",
  "futures-core",
  "futures-sink",
+ "libc",
  "pin-project-lite",
  "tokio",
 ]
@@ -4217,6 +4560,12 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "unicase"
+version = "2.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbc4bc3a9f746d862c45cb89d705aa10f187bb96c76001afab07a0d35ce60142"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.26"
@@ -4229,6 +4578,12 @@ version = "1.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6f5d3c3b1bf09027a88a6bc961fc00497d651009560b5463668dc81b0fa87a8"
 
+[[package]]
+name = "untrusted"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
+
 [[package]]
 name = "url"
 version = "2.5.8"
@@ -4299,8 +4654,10 @@ dependencies = [
  "flate2",
  "image",
  "percent-encoding",
+ "reqwest",
  "rusqlite",
  "rusqlite_migration",
+ "rustls",
  "serde",
  "serde_json",
  "sha2",
@@ -4312,6 +4669,7 @@ dependencies = [
  "tauri-plugin-window-state",
  "tempfile",
  "thiserror 2.0.21",
+ "tokio",
  "uuid",
  "zip",
 ]
@@ -4515,6 +4873,15 @@ dependencies = [
  "system-deps",
 ]
 
+[[package]]
+name = "webpki-root-certs"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b96554aa2acc8ccdb7e1c9a58a7a68dd5d13bccc69cd124cb09406db612a1c9b"
+dependencies = [
+ "rustls-pki-types",
+]
+
 [[package]]
 name = "webview2-com"
 version = "0.39.1"
@@ -4679,6 +5046,17 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-registry"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02752bf7fbdcce7f2a27a742f798510f3e5ad88dbe84871e5168e2120c3d5720"
+dependencies = [
+ "windows-link",
+ "windows-result",
+ "windows-strings",
+]
+
 [[package]]
 name = "windows-result"
 version = "0.4.1"
@@ -4706,6 +5084,15 @@ dependencies = [
  "windows-targets 0.42.2",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.6",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.59.0"
@@ -4995,7 +5382,7 @@ dependencies = [
  "gtk",
  "http",
  "javascriptcore-rs",
- "jni",
+ "jni 0.21.1",
  "libc",
  "ndk",
  "objc2",
@@ -5156,6 +5543,12 @@ dependencies = [
  "synstructure",
 ]
 
+[[package]]
+name = "zeroize"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e13c156562582aa81c60cb29407084cdb54c4164760106ab78e6c5b0858cf64e"
+
 [[package]]
 name = "zerotrie"
 version = "0.2.5"

src-tauri/Cargo.toml

@@ -31,6 +31,11 @@ flate2 = "1"
 zip = { version = "8", default-features = false, features = ["deflate-flate2"] }
 percent-encoding = "2"
 image = { version = "0.25.10", default-features = false, features = ["png", "jpeg", "webp"] }
+# ERPNext integration: all HTTP runs in Rust. TLS is rustls with the `ring` provider only (no aws-lc,
+# which does not cross-compile cleanly under cargo-xwin); roots come from the OS via rustls-platform-verifier.
+reqwest = { version = "0.13.5", default-features = false, features = ["rustls-no-provider", "http2", "charset", "system-proxy", "json", "multipart", "query"] }
+rustls = { version = "0.23", default-features = false, features = ["ring", "std", "tls12"] }
+tokio = { version = "1", features = ["time"] }
 
 # Desktop-only plugins (not available on mobile targets).
 [target.'cfg(not(any(target_os = "android", target_os = "ios")))'.dependencies]
@@ -39,6 +44,7 @@ tauri-plugin-window-state = "2"
 
 [dev-dependencies]
 tempfile = "3"
+tokio = { version = "1", features = ["rt", "macros", "net", "io-util", "time"] }
 
 [features]
 # Production builds embed the frontend and serve it over the custom asset

src-tauri/src/commands/erpnext.rs

@@ -0,0 +1,217 @@
+//! Tauri commands for the ERPNext settings: read/save the configuration, test a connection and load the
+//! lists the settings dropdowns need. The API secret never leaves this module: `erpnext_get_config` returns
+//! `apiSecretSet` only, and every command resolves a blank secret to the stored one on the Rust side.
+//! The push commands send issued invoices and payments (see `integrations::erpnext::push`); the database lock is
+//! never held across a network call.
+
+use crate::integrations::erpnext::client::ErpClient;
+use crate::integrations::erpnext::config::{self, ErpnextConfig, ErpnextConfigInput, ErpnextConfigView};
+use crate::integrations::erpnext::discovery::{self, ic_number_ok, ConnectionTest, ErpnextOptions, LocalFacts};
+use crate::integrations::erpnext::push::{self, PaymentPushResult, PushResult};
+use crate::integrations::SyncStatus;
+use crate::AppState;
+use rusqlite::Connection;
+use tauri::State;
+
+pub fn get_config_impl(conn: &Connection) -> Result<ErpnextConfigView, String> {
+    Ok(config::load(conn)?.view())
+}
+
+/// Merges the form with the stored row (blank secret keeps the stored one) without saving.
+pub fn resolve_config(conn: &Connection, input: ErpnextConfigInput) -> Result<ErpnextConfig, String> {
+    let stored = config::load(conn)?;
+    input.resolve(&stored)
+}
+
+pub fn save_config_impl(conn: &Connection, input: ErpnextConfigInput) -> Result<ErpnextConfigView, String> {
+    let cfg = resolve_config(conn, input)?;
+    config::save(conn, &cfg)?;
+    Ok(cfg.view())
+}
+
+/// What the connection test needs from the local database.
+pub fn local_facts(conn: &Connection) -> Result<LocalFacts, String> {
+    let registration: String = conn
+        .query_row("SELECT gst_registration FROM app_settings WHERE id = 1", [], |r| r.get(0))
+        .map_err(|e| e.to_string())?;
+    let mut stmt = conn
+        .prepare("SELECT number FROM invoices ORDER BY id")
+        .map_err(|e| e.to_string())?;
+    let invalid_numbers = stmt
+        .query_map([], |r| r.get::<_, String>(0))
+        .map_err(|e| e.to_string())?
+        .collect::<rusqlite::Result<Vec<_>>>()
+        .map_err(|e| e.to_string())?
+        .into_iter()
+        .filter(|n| !ic_number_ok(n))
+        .take(5)
+        .collect();
+    let next_number = conn
+        .query_row(
+            "SELECT prefix, padding, next_number FROM invoice_series WHERE is_active = 1 ORDER BY id DESC LIMIT 1",
+            [],
+            |r| Ok((r.get::<_, String>(0)?, r.get::<_, i64>(1)?, r.get::<_, i64>(2)?)),
+        )
+        .ok()
+        .map(|(prefix, padding, next)| crate::db::format_number(&prefix, padding, next));
+    Ok(LocalFacts { vendor_registered: registration != "unregistered", invalid_numbers, next_number })
+}
+
+#[tauri::command]
+pub fn erpnext_get_config(state: State<AppState>) -> Result<ErpnextConfigView, String> {
+    let conn = state.db.lock().map_err(|e| e.to_string())?;
+    get_config_impl(&conn)
+}
+
+/// A blank `apiSecret` keeps the stored secret; a value replaces it; `clearSecret` removes it.
+#[tauri::command]
+pub fn erpnext_save_config(state: State<AppState>, config: ErpnextConfigInput) -> Result<ErpnextConfigView, String> {
+    let conn = state.db.lock().map_err(|e| e.to_string())?;
+    save_config_impl(&conn, config)
+}
+
+/// Tests the form values as typed (saved or not). The database lock is released before any network call.
+#[tauri::command]
+pub async fn erpnext_test_connection(
+    state: State<'_, AppState>,
+    config: ErpnextConfigInput,
+) -> Result<ConnectionTest, String> {
+    let (cfg, local) = {
+        let conn = state.db.lock().map_err(|e| e.to_string())?;
+        (resolve_config(&conn, config)?, local_facts(&conn)?)
+    };
+    let client = ErpClient::from_config(&cfg)?;
+    Ok(discovery::test_connection(&client, &cfg, &local).await?)
+}
+
+/// Loads the dropdown lists. Company-scoped lists use `config.company`.
+#[tauri::command]
+pub async fn erpnext_load_options(
+    state: State<'_, AppState>,
+    config: ErpnextConfigInput,
+) -> Result<ErpnextOptions, String> {
+    let cfg = {
+        let conn = state.db.lock().map_err(|e| e.to_string())?;
+        resolve_config(&conn, config)?
+    };
+    let client = ErpClient::from_config(&cfg)?;
+    Ok(client.load_options(&cfg.company).await?)
+}
+
+/// A client for the saved settings, or a readable reason why there is none.
+fn saved_client(state: &AppState) -> Result<ErpClient, String> {
+    let cfg = {
+        let conn = state.db.lock().map_err(|e| e.to_string())?;
+        config::load(&conn)?
+    };
+    if cfg.base_url.trim().is_empty() || cfg.api_key.trim().is_empty() || !cfg.api_secret.is_set() {
+        return Err("ERPNext is not set up yet: enter the address, API key and API secret in Settings.".into());
+    }
+    Ok(ErpClient::from_config(&cfg)?)
+}
+
+/// Sends one issued invoice. `submit` omitted follows the "submit on push" setting. A failure comes back as a
+/// result with `ok: false` (and is recorded), not as an `Err`.
+#[tauri::command]
+pub async fn erpnext_push_invoice(
+    state: State<'_, AppState>,
+    id: i64,
+    submit: Option<bool>,
+) -> Result<PushResult, String> {
+    let http = saved_client(&state)?;
+    Ok(push::push_invoice(&state.db, &state.local_data_dir, &http, id, submit).await)
+}
+
+/// Sends several invoices one after another; one row's failure never stops the others.
+#[tauri::command]
+pub async fn erpnext_push_invoices(
+    state: State<'_, AppState>,
+    ids: Vec<i64>,
+    submit: Option<bool>,
+) -> Result<Vec<PushResult>, String> {
+    let http = saved_client(&state)?;
+    Ok(push::push_invoices(&state.db, &state.local_data_dir, &http, &ids, submit).await)
+}
+
+#[tauri::command]
+pub async fn erpnext_push_payment(state: State<'_, AppState>, payment_id: i64) -> Result<PaymentPushResult, String> {
+    let http = saved_client(&state)?;
+    Ok(push::push_payment(&state.db, &http, payment_id).await)
+}
+
+#[tauri::command]
+pub fn erpnext_sync_status(state: State<AppState>, id: i64) -> Result<SyncStatus, String> {
+    let conn = state.db.lock().map_err(|e| e.to_string())?;
+    push::sync_status(&conn, id)
+}
+
+/// The sync state of every invoice that has one, for the History list.
+#[tauri::command]
+pub fn erpnext_sync_statuses(state: State<AppState>) -> Result<Vec<SyncStatus>, String> {
+    let conn = state.db.lock().map_err(|e| e.to_string())?;
+    push::sync_statuses(&conn)
+}
+
+/// `<base>/app/sales-invoice/<name>` for an invoice that was sent.
+#[tauri::command]
+pub fn erpnext_open_url(state: State<AppState>, id: i64) -> Result<String, String> {
+    let conn = state.db.lock().map_err(|e| e.to_string())?;
+    push::open_url(&conn, id)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    fn input(extra: serde_json::Value) -> ErpnextConfigInput {
+        let mut base = json!({ "baseUrl": "https://erp.example.com", "apiKey": "key1", "company": "Test Co" });
+        base.as_object_mut().unwrap().extend(extra.as_object().unwrap().clone());
+        serde_json::from_value(base).unwrap()
+    }
+
+    #[test]
+    fn saved_config_is_returned_without_the_secret() {
+        let conn = crate::db::open_in_memory().unwrap();
+        let view = save_config_impl(&conn, input(json!({ "apiSecret": "super-secret-value", "submitOnPush": true }))).unwrap();
+        assert!(view.api_secret_set);
+        let shown = serde_json::to_string(&get_config_impl(&conn).unwrap()).unwrap();
+        assert!(!shown.contains("super-secret-value"));
+        assert!(shown.contains("\"apiSecretSet\":true"));
+        assert!(shown.contains("\"company\":\"Test Co\""));
+
+        // Saving again with a blank secret keeps it for the connection test too.
+        save_config_impl(&conn, input(json!({ "company": "Other Co" }))).unwrap();
+        let resolved = resolve_config(&conn, input(json!({}))).unwrap();
+        assert_eq!(resolved.api_secret.expose(), "super-secret-value");
+        assert_eq!(resolved.company, "Test Co");
+    }
+
+    #[test]
+    fn test_values_are_resolved_without_saving() {
+        let conn = crate::db::open_in_memory().unwrap();
+        let resolved = resolve_config(&conn, input(json!({ "apiSecret": "typed-not-saved" }))).unwrap();
+        assert_eq!(resolved.api_secret.expose(), "typed-not-saved");
+        assert!(!get_config_impl(&conn).unwrap().api_secret_set);
+    }
+
+    #[test]
+    fn local_facts_report_registration_numbers_and_the_next_number() {
+        let conn = crate::db::open_in_memory().unwrap();
+        let facts = local_facts(&conn).unwrap();
+        assert!(!facts.vendor_registered);
+        assert!(facts.invalid_numbers.is_empty());
+        assert!(facts.next_number.is_some());
+
+        conn.execute("UPDATE app_settings SET gst_registration = 'regular'", []).unwrap();
+        conn.execute(
+            "INSERT INTO invoices (number, invoice_date, created_at, updated_at)
+             VALUES ('INV/2026-001', '2026-04-01', 'n', 'n'), ('INVOICE/2026/000001', '2026-04-01', 'n', 'n')",
+            [],
+        )
+        .unwrap();
+        let facts = local_facts(&conn).unwrap();
+        assert!(facts.vendor_registered);
+        assert_eq!(facts.invalid_numbers, ["INVOICE/2026/000001"]);
+    }
+}

src-tauri/src/commands/mod.rs

@@ -2,6 +2,7 @@ pub mod archive;
 pub mod assets;
 pub mod backup;
 pub mod clients;
+pub mod erpnext;
 pub mod files;
 pub mod fonts;
 pub mod invoice;

src-tauri/src/commands/payments.rs

@@ -30,6 +30,9 @@ pub struct Payment {
     pub reference: String,
     pub notes: String,
     pub created_at: String,
+    /// Name of the Payment Entry on ERPNext once this payment was sent; `None` until then.
+    #[serde(default)]
+    pub erpnext_payment_entry: Option<String>,
 }
 
 #[derive(Debug, Clone, Deserialize)]
@@ -127,10 +130,11 @@ fn map_payment(r: &rusqlite::Row) -> rusqlite::Result<Payment> {
         reference: r.get(6)?,
         notes: r.get(7)?,
         created_at: r.get(8)?,
+        erpnext_payment_entry: r.get::<_, Option<String>>(9)?.filter(|e| !e.trim().is_empty()),
     })
 }
 
-const COLS: &str = "id, invoice_id, paid_on, amount_paise, tds_paise, mode, reference, notes, created_at";
+const COLS: &str = "id, invoice_id, paid_on, amount_paise, tds_paise, mode, reference, notes, created_at, erpnext_payment_entry";
 
 pub fn record_payment_impl(conn: &mut Connection, input: PaymentInput) -> Result<Payment, String> {
     let db = |e: rusqlite::Error| e.to_string();

src-tauri/src/db.rs

@@ -10,7 +10,7 @@ const MAX_BACKUPS: usize = 10;
 const BACKUP_PREFIX: &str = "voiced-pre-v";
 
 /// Highest schema version, i.e. the number of entries in `migrations()`.
-pub(crate) const LATEST_VERSION: i64 = 9;
+pub(crate) const LATEST_VERSION: i64 = 11;
 
 #[derive(Debug, thiserror::Error)]
 pub enum DbError {
@@ -270,6 +270,81 @@ const M9: &str = r#"
 ALTER TABLE app_settings ADD COLUMN auto_backup INTEGER NOT NULL DEFAULT 1;
 "#;
 
+/// Version 10: ERPNext integration. `erpnext_config` is a single row (inserted here, so reading it is a plain SELECT)
+/// holding the connection, the company/account/master mapping and the toggles. `api_secret` is stored here and is never
+/// returned to the webview. `erpnext_sync` tracks what was pushed per invoice; issued invoices themselves are untouched.
+/// The remote names on clients, payments and item presets are nullable: NULL means "not linked yet".
+const M10: &str = r#"
+CREATE TABLE erpnext_config (
+    id                       INTEGER PRIMARY KEY CHECK (id = 1),
+    base_url                 TEXT NOT NULL DEFAULT '',
+    api_key                  TEXT NOT NULL DEFAULT '',
+    api_secret               TEXT NOT NULL DEFAULT '',
+    extra_ca_pem             TEXT NOT NULL DEFAULT '',
+    company                  TEXT NOT NULL DEFAULT '',
+    company_address          TEXT NOT NULL DEFAULT '',
+    naming_mode              TEXT NOT NULL DEFAULT 'mirror' CHECK (naming_mode IN ('mirror', 'series')),
+    naming_series            TEXT NOT NULL DEFAULT '',
+    income_account           TEXT NOT NULL DEFAULT '',
+    cost_center              TEXT NOT NULL DEFAULT '',
+    cgst_account             TEXT NOT NULL DEFAULT '',
+    sgst_account             TEXT NOT NULL DEFAULT '',
+    utgst_account            TEXT NOT NULL DEFAULT '',
+    igst_account             TEXT NOT NULL DEFAULT '',
+    tax_template_intra       TEXT NOT NULL DEFAULT '',
+    tax_template_inter       TEXT NOT NULL DEFAULT '',
+    payment_bank_account     TEXT NOT NULL DEFAULT '',
+    tds_account              TEXT NOT NULL DEFAULT '',
+    default_item_code        TEXT NOT NULL DEFAULT '',
+    uom_map                  TEXT NOT NULL DEFAULT '{"second":"Second","minute":"Minute","hour":"Hour","session":"Nos","unit":"Nos"}',
+    customer_group           TEXT NOT NULL DEFAULT '',
+    territory                TEXT NOT NULL DEFAULT '',
+    selling_price_list       TEXT NOT NULL DEFAULT '',
+    submit_on_push           INTEGER NOT NULL DEFAULT 0,
+    attach_pdf               INTEGER NOT NULL DEFAULT 1,
+    auto_push_on_issue       INTEGER NOT NULL DEFAULT 0,
+    create_missing_customers INTEGER NOT NULL DEFAULT 1,
+    last_detect_result       TEXT NOT NULL DEFAULT '',
+    updated_at               TEXT
+);
+INSERT INTO erpnext_config (id) VALUES (1);
+
+CREATE TABLE erpnext_sync (
+    invoice_id       INTEGER PRIMARY KEY REFERENCES invoices(id),
+    remote_name      TEXT NOT NULL DEFAULT '',
+    remote_docstatus INTEGER NOT NULL DEFAULT 0,
+    status           TEXT NOT NULL DEFAULT 'pending' CHECK (status IN ('pending', 'synced', 'error')),
+    last_error       TEXT NOT NULL DEFAULT '',
+    payload_hash     TEXT NOT NULL DEFAULT '',
+    synced_at        TEXT
+);
+
+ALTER TABLE clients ADD COLUMN erpnext_customer TEXT;
+ALTER TABLE clients ADD COLUMN erpnext_address TEXT;
+ALTER TABLE payments ADD COLUMN erpnext_payment_entry TEXT;
+ALTER TABLE item_presets ADD COLUMN erpnext_item_code TEXT;
+"#;
+
+/// Version 11: ERPNext push state. `erpnext_sync.status` gains `conflict` (the remote document exists with a different
+/// total; we never overwrite it) and `attachment_sha256` records which archived PDF was uploaded so it is never attached
+/// twice. SQLite cannot alter a CHECK constraint, so the table is rebuilt; M10 rows are copied over.
+const M11: &str = r#"
+CREATE TABLE erpnext_sync_new (
+    invoice_id        INTEGER PRIMARY KEY REFERENCES invoices(id),
+    remote_name       TEXT NOT NULL DEFAULT '',
+    remote_docstatus  INTEGER NOT NULL DEFAULT 0,
+    status            TEXT NOT NULL DEFAULT 'pending' CHECK (status IN ('pending', 'synced', 'error', 'conflict')),
+    last_error        TEXT NOT NULL DEFAULT '',
+    payload_hash      TEXT NOT NULL DEFAULT '',
+    synced_at         TEXT,
+    attachment_sha256 TEXT NOT NULL DEFAULT ''
+);
+INSERT INTO erpnext_sync_new (invoice_id, remote_name, remote_docstatus, status, last_error, payload_hash, synced_at)
+    SELECT invoice_id, remote_name, remote_docstatus, status, last_error, payload_hash, synced_at FROM erpnext_sync;
+DROP TABLE erpnext_sync;
+ALTER TABLE erpnext_sync_new RENAME TO erpnext_sync;
+"#;
+
 fn migrations() -> Migrations<'static> {
     Migrations::new(vec![
         M::up(SCHEMA),
@@ -281,6 +356,8 @@ fn migrations() -> Migrations<'static> {
         M::up(M7),
         M::up(M8),
         M::up(M9),
+        M::up(M10),
+        M::up(M11),
     ])
 }
 
@@ -786,6 +863,121 @@ CREATE INDEX IF NOT EXISTS idx_invoices_created ON invoices(created_at DESC);
         assert_eq!(rows[2].5, "unregistered");
     }
 
+    #[test]
+    fn m10_fresh_database_has_the_erpnext_tables_and_a_default_config_row() {
+        let conn = open_in_memory().unwrap();
+        let (naming, submit, attach, auto_push, create_customers, secret, uom): (String, i64, i64, i64, i64, String, String) = conn
+            .query_row(
+                "SELECT naming_mode, submit_on_push, attach_pdf, auto_push_on_issue, create_missing_customers, api_secret, uom_map
+                 FROM erpnext_config WHERE id = 1",
+                [],
+                |r| Ok((r.get(0)?, r.get(1)?, r.get(2)?, r.get(3)?, r.get(4)?, r.get(5)?, r.get(6)?)),
+            )
+            .unwrap();
+        assert_eq!((naming.as_str(), submit, attach, auto_push, create_customers), ("mirror", 0, 1, 0, 1));
+        assert_eq!(secret, "");
+        assert!(serde_json::from_str::<serde_json::Value>(&uom).is_ok());
+        let rows: i64 = conn.query_row("SELECT COUNT(*) FROM erpnext_config", [], |r| r.get(0)).unwrap();
+        assert_eq!(rows, 1);
+        // Single row only.
+        assert!(conn.execute("INSERT INTO erpnext_config (id) VALUES (2)", []).is_err());
+        conn.prepare("SELECT invoice_id, remote_name, remote_docstatus, status, last_error, payload_hash, synced_at FROM erpnext_sync")
+            .unwrap();
+        conn.prepare("SELECT erpnext_customer, erpnext_address FROM clients").unwrap();
+        conn.prepare("SELECT erpnext_payment_entry FROM payments").unwrap();
+        conn.prepare("SELECT erpnext_item_code FROM item_presets").unwrap();
+    }
+
+    #[test]
+    fn m10_upgrade_from_v9_keeps_existing_data_and_new_columns_are_null() {
+        let mut conn = Connection::open_in_memory().unwrap();
+        let v9 = vec![
+            M::up(SCHEMA), M::up(M2), M::up(M3), M::up(M4), M::up(M5), M::up(M6), M::up(M7), M::up(M8), M::up(M9),
+        ];
+        Migrations::new(v9).to_latest(&mut conn).unwrap();
+        assert_eq!(user_version(&conn), 9);
+        conn.execute("INSERT INTO clients (name, gstin, created_at) VALUES ('Acme', '29ABCDE1234F1Z5', 'now')", []).unwrap();
+        conn.execute("INSERT INTO item_presets (description, rate_paise, created_at) VALUES ('Design', 500000, 'now')", []).unwrap();
+        conn.execute(
+            "INSERT INTO invoices (number, invoice_date, created_at, updated_at) VALUES ('INV/2026-001', '2026-04-01', 'now', 'now')",
+            [],
+        )
+        .unwrap();
+        conn.execute(
+            "INSERT INTO payments (invoice_id, paid_on, amount_paise, mode, created_at) VALUES (1, '2026-04-10', 12345, 'upi', 'now')",
+            [],
+        )
+        .unwrap();
+
+        migrations().to_latest(&mut conn).unwrap();
+        assert_eq!(user_version(&conn), LATEST_VERSION);
+
+        let (name, gstin, customer, address): (String, String, Option<String>, Option<String>) = conn
+            .query_row("SELECT name, gstin, erpnext_customer, erpnext_address FROM clients", [], |r| {
+                Ok((r.get(0)?, r.get(1)?, r.get(2)?, r.get(3)?))
+            })
+            .unwrap();
+        assert_eq!((name.as_str(), gstin.as_str(), customer, address), ("Acme", "29ABCDE1234F1Z5", None, None));
+        let (desc, rate, code): (String, i64, Option<String>) = conn
+            .query_row("SELECT description, rate_paise, erpnext_item_code FROM item_presets", [], |r| {
+                Ok((r.get(0)?, r.get(1)?, r.get(2)?))
+            })
+            .unwrap();
+        assert_eq!((desc.as_str(), rate, code), ("Design", 500000, None));
+        let (paid, entry): (i64, Option<String>) = conn
+            .query_row("SELECT amount_paise, erpnext_payment_entry FROM payments", [], |r| Ok((r.get(0)?, r.get(1)?)))
+            .unwrap();
+        assert_eq!((paid, entry), (12345, None));
+        let number: String = conn.query_row("SELECT number FROM invoices", [], |r| r.get(0)).unwrap();
+        assert_eq!(number, "INV/2026-001");
+
+        // The config row exists with defaults, and a sync row can reference the invoice.
+        let enabled: i64 = conn.query_row("SELECT COUNT(*) FROM erpnext_config WHERE id = 1", [], |r| r.get(0)).unwrap();
+        assert_eq!(enabled, 1);
+        conn.execute("INSERT INTO erpnext_sync (invoice_id, remote_name, status) VALUES (1, 'INV/2026-001', 'synced')", []).unwrap();
+        assert!(conn.execute("INSERT INTO erpnext_sync (invoice_id, status) VALUES (1, 'bogus')", []).is_err());
+    }
+
+    #[test]
+    fn m11_rebuilds_the_sync_table_keeping_rows_and_allowing_conflict() {
+        let mut conn = Connection::open_in_memory().unwrap();
+        let v10 = vec![
+            M::up(SCHEMA), M::up(M2), M::up(M3), M::up(M4), M::up(M5), M::up(M6), M::up(M7), M::up(M8), M::up(M9), M::up(M10),
+        ];
+        Migrations::new(v10).to_latest(&mut conn).unwrap();
+        assert_eq!(user_version(&conn), 10);
+        conn.execute(
+            "INSERT INTO invoices (number, invoice_date, created_at, updated_at) VALUES ('INV/2026-001', '2026-04-01', 'now', 'now')",
+            [],
+        )
+        .unwrap();
+        conn.execute(
+            "INSERT INTO erpnext_sync (invoice_id, remote_name, remote_docstatus, status, payload_hash, synced_at)
+             VALUES (1, 'INV/2026-001', 1, 'synced', 'abc', '2026-04-02T00:00:00Z')",
+            [],
+        )
+        .unwrap();
+        assert!(conn.execute("UPDATE erpnext_sync SET status = 'conflict'", []).is_err());
+
+        migrations().to_latest(&mut conn).unwrap();
+        assert_eq!(user_version(&conn), 11);
+        let row: (String, i64, String, String, String, Option<String>) = conn
+            .query_row(
+                "SELECT remote_name, remote_docstatus, status, payload_hash, attachment_sha256, synced_at FROM erpnext_sync WHERE invoice_id = 1",
+                [],
+                |r| Ok((r.get(0)?, r.get(1)?, r.get(2)?, r.get(3)?, r.get(4)?, r.get(5)?)),
+            )
+            .unwrap();
+        assert_eq!(
+            row,
+            ("INV/2026-001".into(), 1, "synced".into(), "abc".into(), String::new(), Some("2026-04-02T00:00:00Z".into()))
+        );
+        conn.execute("UPDATE erpnext_sync SET status = 'conflict'", []).unwrap();
+        assert!(conn.execute("UPDATE erpnext_sync SET status = 'bogus'", []).is_err());
+        // The unique key still guards one row per invoice.
+        assert!(conn.execute("INSERT INTO erpnext_sync (invoice_id, status) VALUES (1, 'error')", []).is_err());
+    }
+
     fn build_v1_database(path: &Path) {
         let conn = Connection::open(path).unwrap();
         conn.execute_batch(V1_SCHEMA).unwrap();

src-tauri/src/integrations/erpnext/client.rs

@@ -0,0 +1,517 @@
+//! HTTP client for a Frappe/ERPNext site. All requests run here, in Rust: a webview `fetch` from
+//! `tauri://localhost` would be blocked by CORS.
+//!
+//! TLS is rustls with the `ring` provider (installed once, process-wide). Roots come from the OS through
+//! rustls-platform-verifier; an optional extra CA PEM is merged in for self-hosted sites.
+
+use super::config::{ErpnextConfig, Secret};
+use super::errors::{ErpError, ErrorKind};
+use reqwest::header::{HeaderMap, HeaderValue, ACCEPT, AUTHORIZATION, RETRY_AFTER};
+use reqwest::{Method, Url};
+use serde_json::Value;
+use std::sync::Once;
+use std::time::Duration;
+
+static CRYPTO_PROVIDER: Once = Once::new();
+
+/// Installs the ring crypto provider for rustls. Idempotent; must run before the first client is built.
+pub fn ensure_crypto_provider() {
+    CRYPTO_PROVIDER.call_once(|| {
+        // Err means another provider is already installed, which is fine for our purposes.
+        let _ = rustls::crypto::ring::default_provider().install_default();
+    });
+}
+
+#[derive(Debug, Clone)]
+pub struct ClientOptions {
+    pub connect_timeout: Duration,
+    pub read_timeout: Duration,
+    pub total_timeout: Duration,
+    /// Retries after the first attempt.
+    pub max_retries: u32,
+    pub backoff_base: Duration,
+    pub max_backoff: Duration,
+}
+
+impl Default for ClientOptions {
+    fn default() -> Self {
+        ClientOptions {
+            connect_timeout: Duration::from_secs(10),
+            read_timeout: Duration::from_secs(30),
+            total_timeout: Duration::from_secs(60),
+            max_retries: 3,
+            backoff_base: Duration::from_millis(500),
+            max_backoff: Duration::from_secs(8),
+        }
+    }
+}
+
+/// Plain http is only for a local development site; anything else must use https.
+pub fn is_local_dev_host(host: &str) -> bool {
+    let host = host.trim_end_matches('.').to_ascii_lowercase();
+    host == "localhost" || host == "127.0.0.1" || host.ends_with(".localhost") || host.ends_with(".test")
+}
+
+/// Normalises what the user typed into `scheme://host[:port][/prefix]` without a trailing slash.
+/// A missing scheme means https, except for local development hosts, which get http.
+pub fn normalize_base_url(raw: &str) -> Result<String, ErpError> {
+    let raw = raw.trim();
+    if raw.is_empty() {
+        return Err(ErpError::config("The ERPNext address is empty."));
+    }
+    let with_scheme = if raw.contains("://") {
+        raw.to_string()
+    } else {
+        let host = raw.split(['/', ':']).next().unwrap_or("");
+        let scheme = if is_local_dev_host(host) { "http" } else { "https" };
+        format!("{scheme}://{raw}")
+    };
+    let mut url = Url::parse(&with_scheme).map_err(|e| ErpError::config(format!("The ERPNext address is not valid: {e}")))?;
+    let host = url
+        .host_str()
+        .ok_or_else(|| ErpError::config("The ERPNext address has no host name."))?
+        .to_string();
+    match url.scheme() {
+        "https" => {}
+        "http" => {
+            if !is_local_dev_host(&host) {
+                return Err(ErpError::config(
+                    "Use an https:// address. Plain http is only allowed for localhost, 127.0.0.1, *.localhost and *.test.",
+                ));
+            }
+        }
+        other => return Err(ErpError::config(format!("Unsupported address scheme \"{other}\"; use https://."))),
+    }
+    if !url.username().is_empty() || url.password().is_some() {
+        return Err(ErpError::config("Do not put credentials in the address; use the API key and secret fields."));
+    }
+    url.set_query(None);
+    url.set_fragment(None);
+    Ok(url.as_str().trim_end_matches('/').to_string())
+}
+
+/// A file to upload through a multipart POST.
+pub struct Upload<'a> {
+    pub file_name: &'a str,
+    pub mime: &'a str,
+    pub bytes: &'a [u8],
+    pub fields: &'a [(&'a str, String)],
+}
+
+enum Payload<'a> {
+    None,
+    Json(&'a Value),
+    Upload(&'a Upload<'a>),
+}
+
+pub struct ErpClient {
+    http: reqwest::Client,
+    base: Url,
+    opts: ClientOptions,
+    /// Strings scrubbed from every error message.
+    secrets: Vec<String>,
+}
+
+impl std::fmt::Debug for ErpClient {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ErpClient").field("base", &self.base.as_str()).finish_non_exhaustive()
+    }
+}
+
+impl ErpClient {
+    pub fn new(
+        base_url: &str,
+        api_key: &str,
+        api_secret: &Secret,
+        extra_ca_pem: &str,
+        opts: ClientOptions,
+    ) -> Result<Self, ErpError> {
+        ensure_crypto_provider();
+        let base = Url::parse(&normalize_base_url(base_url)?).map_err(|e| ErpError::config(e.to_string()))?;
+        if api_key.trim().is_empty() || !api_secret.is_set() {
+            return Err(ErpError::config("Enter the API key and API secret."));
+        }
+        let mut auth = HeaderValue::from_str(&format!("token {}:{}", api_key.trim(), api_secret.expose()))
+            .map_err(|_| ErpError::config("The API key or secret contains characters that cannot be sent."))?;
+        auth.set_sensitive(true);
+
+        let mut headers = HeaderMap::new();
+        headers.insert(AUTHORIZATION, auth);
+        // Frappe answers `Accept: text/*` with HTML; always ask for JSON.
+        headers.insert(ACCEPT, HeaderValue::from_static("application/json"));
+
+        let mut builder = reqwest::Client::builder()
+            .default_headers(headers)
+            .user_agent(concat!("Voiced/", env!("CARGO_PKG_VERSION")))
+            .connect_timeout(opts.connect_timeout)
+            .read_timeout(opts.read_timeout)
+            .timeout(opts.total_timeout)
+            // A redirect drops the body or the auth header; surface it instead of guessing.
+            .redirect(reqwest::redirect::Policy::none());
+        if !extra_ca_pem.trim().is_empty() {
+            let certs = reqwest::Certificate::from_pem_bundle(extra_ca_pem.trim().as_bytes())
+                .map_err(|_| ErpError::config("The extra CA certificate is not valid PEM."))?;
+            if certs.is_empty() {
+                return Err(ErpError::config("The extra CA certificate field holds no certificate."));
+            }
+            builder = builder.tls_certs_merge(certs);
+        }
+        let http = builder
+            .build()
+            .map_err(|e| ErpError::config(format!("Could not set up the HTTP client: {}", error_chain(&e))))?;
+        Ok(ErpClient {
+            http,
+            base,
+            opts,
+            secrets: vec![api_secret.expose().to_string(), api_key.trim().to_string()],
+        })
+    }
+
+    pub fn from_config(cfg: &ErpnextConfig) -> Result<Self, ErpError> {
+        Self::new(&cfg.base_url, &cfg.api_key, &cfg.api_secret, &cfg.extra_ca_pem, ClientOptions::default())
+    }
+
+    pub fn base_url(&self) -> &str {
+        self.base.as_str().trim_end_matches('/')
+    }
+
+    fn url(&self, segments: &[&str]) -> Url {
+        let mut url = self.base.clone();
+        if let Ok(mut path) = url.path_segments_mut() {
+            path.pop_if_empty().extend(segments);
+        }
+        url
+    }
+
+    /// GET, retried on 429, 5xx and timeouts.
+    pub async fn get(&self, segments: &[&str], query: &[(&str, String)]) -> Result<Value, ErpError> {
+        self.send(Method::GET, segments, query, Payload::None, true).await
+    }
+
+    /// POST with a JSON body. 429 is always retried (the server refused before doing anything). 5xx and
+    /// timeouts are retried only when `idempotent` is true, because the server may have processed the
+    /// request: a mirrored-name Sales Invoice is idempotent (a repeat is a 409), a series-named one is not.
+    pub async fn post(&self, segments: &[&str], body: &Value, idempotent: bool) -> Result<Value, ErpError> {
+        self.send(Method::POST, segments, &[], Payload::Json(body), idempotent).await
+    }
+
+    /// Multipart POST carrying one file part named `file` (the name Frappe's `upload_file` reads; the file
+    /// name travels in the part's Content-Disposition) plus plain text fields. Never retried after a 5xx or
+    /// timeout, because an upload that may have landed would attach the file twice.
+    pub async fn post_file(&self, segments: &[&str], upload: &Upload<'_>) -> Result<Value, ErpError> {
+        self.send(Method::POST, segments, &[], Payload::Upload(upload), false).await
+    }
+
+    async fn send(
+        &self,
+        method: Method,
+        segments: &[&str],
+        query: &[(&str, String)],
+        payload: Payload<'_>,
+        retry_ambiguous: bool,
+    ) -> Result<Value, ErpError> {
+        let mut attempt: u32 = 0;
+        loop {
+            let mut req = self.http.request(method.clone(), self.url(segments));
+            if !query.is_empty() {
+                req = req.query(query);
+            }
+            match &payload {
+                Payload::None => {}
+                Payload::Json(b) => req = req.json(*b),
+                Payload::Upload(u) => {
+                    let part = reqwest::multipart::Part::bytes(u.bytes.to_vec())
+                        .file_name(u.file_name.to_string())
+                        .mime_str(u.mime)
+                        .map_err(|e| ErpError::config(format!("Bad upload type: {e}")))?;
+                    let mut form = reqwest::multipart::Form::new();
+                    for (k, v) in u.fields {
+                        form = form.text(k.to_string(), v.clone());
+                    }
+                    req = req.multipart(form.part("file", part));
+                }
+            }
+            let can_retry = attempt < self.opts.max_retries;
+            match req.send().await {
+                Ok(resp) => {
+                    let status = resp.status();
+                    let retry_after = resp
+                        .headers()
+                        .get(RETRY_AFTER)
+                        .and_then(|v| v.to_str().ok())
+                        .and_then(|v| v.trim().parse::<u64>().ok())
+                        .map(Duration::from_secs);
+                    let location = resp
+                        .headers()
+                        .get(reqwest::header::LOCATION)
+                        .and_then(|v| v.to_str().ok())
+                        .map(str::to_string);
+                    let text = match resp.text().await {
+                        Ok(t) => t,
+                        Err(e) => {
+                            if e.is_timeout() && retry_ambiguous && can_retry {
+                                self.backoff(attempt, None).await;
+                                attempt += 1;
+                                continue;
+                            }
+                            return Err(self.map_transport(&e));
+                        }
+                    };
+                    if status.is_success() {
+                        return self.parse_success(&text);
+                    }
+                    let retryable = status.as_u16() == 429 || (status.is_server_error() && retry_ambiguous);
+                    if retryable && can_retry {
+                        self.backoff(attempt, retry_after).await;
+                        attempt += 1;
+                        continue;
+                    }
+                    if status.is_redirection() {
+                        let to = location.unwrap_or_else(|| "another address".to_string());
+                        return Err(self.scrub(ErpError::protocol(format!(
+                            "The server redirected the request to {to}. Use the final address (usually https://) in the ERPNext address field."
+                        ))));
+                    }
+                    return Err(self.scrub(ErpError::from_response(status.as_u16(), &text)));
+                }
+                Err(e) => {
+                    if e.is_timeout() && retry_ambiguous && can_retry {
+                        self.backoff(attempt, None).await;
+                        attempt += 1;
+                        continue;
+                    }
+                    return Err(self.map_transport(&e));
+                }
+            }
+        }
+    }
+
+    async fn backoff(&self, attempt: u32, retry_after: Option<Duration>) {
+        let exp = self.opts.backoff_base.saturating_mul(1u32 << attempt.min(10));
+        let delay = retry_after.unwrap_or(exp).min(self.opts.max_backoff);
+        tokio::time::sleep(delay).await;
+    }
+
+    fn parse_success(&self, text: &str) -> Result<Value, ErpError> {
+        if text.trim().is_empty() {
+            return Ok(Value::Null);
+        }
+        serde_json::from_str(text).map_err(|_| {
+            ErpError::protocol(
+                "The server did not return JSON. Check the address: it should be the root of your ERPNext site.",
+            )
+        })
+    }
+
+    fn scrub(&self, err: ErpError) -> ErpError {
+        let secrets: Vec<&str> = self.secrets.iter().map(String::as_str).collect();
+        err.redacted(&secrets)
+    }
+
+    fn map_transport(&self, e: &reqwest::Error) -> ErpError {
+        let chain = error_chain(e);
+        let err = if e.is_timeout() {
+            ErpError::new(ErrorKind::Timeout, "The ERPNext server did not answer in time.")
+        } else if e.is_connect() {
+            let lower = chain.to_ascii_lowercase();
+            let hint = if lower.contains("certificate") || lower.contains("unknownissuer") {
+                " The certificate is not trusted: paste the site's CA certificate into the extra CA field."
+            } else {
+                ""
+            };
+            ErpError::new(ErrorKind::Network, format!("Could not connect to the ERPNext server ({chain}).{hint}"))
+        } else {
+            ErpError::new(ErrorKind::Network, format!("The request to ERPNext failed ({chain})."))
+        };
+        self.scrub(err)
+    }
+}
+
+/// `a: b: c` for an error and its sources.
+fn error_chain(e: &dyn std::error::Error) -> String {
+    let mut parts = vec![e.to_string()];
+    let mut source = e.source();
+    while let Some(s) = source {
+        let text = s.to_string();
+        if parts.last() != Some(&text) {
+            parts.push(text);
+        }
+        source = s.source();
+    }
+    parts.join(": ")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::integrations::erpnext::testutil::{client, fast_opts, reply, serve, Reply};
+    use serde_json::json;
+    use std::sync::atomic::Ordering;
+
+    // ---- URL rules ----
+
+    #[test]
+    fn https_is_accepted_and_normalised() {
+        assert_eq!(normalize_base_url(" https://Erp.Example.com/ ").unwrap(), "https://erp.example.com");
+        assert_eq!(normalize_base_url("erp.example.com").unwrap(), "https://erp.example.com");
+        assert_eq!(normalize_base_url("https://erp.example.com:8443/sub/?a=1#x").unwrap(), "https://erp.example.com:8443/sub");
+    }
+
+    #[test]
+    fn http_is_only_for_local_development_hosts() {
+        for ok in [
+            "http://localhost:8000",
+            "http://127.0.0.1:8080",
+            "http://mysite.localhost:8000",
+            "http://erp.test",
+            "localhost:8000",
+            "127.0.0.1:8000",
+        ] {
+            let url = normalize_base_url(ok).unwrap_or_else(|e| panic!("{ok}: {e}"));
+            assert!(url.starts_with("http://"), "{ok} -> {url}");
+        }
+        for bad in ["http://erp.example.com", "http://192.168.1.10:8000", "http://localhost.evil.com", "http://notlocalhost"] {
+            assert!(normalize_base_url(bad).is_err(), "{bad} must be refused");
+        }
+    }
+
+    #[test]
+    fn other_schemes_credentials_and_blanks_are_refused() {
+        for bad in ["ftp://erp.example.com", "file:///etc/passwd", "https://user:pw@erp.example.com", "", "   ", "https://"] {
+            assert!(normalize_base_url(bad).is_err(), "{bad:?} must be refused");
+        }
+    }
+
+    #[tokio::test]
+    async fn sends_token_auth_and_a_json_accept_header() {
+        let mock = serve(vec![reply(200, json!({ "message": "Sample@example.com" }))]).await;
+        let value = client(&mock)
+            .get(&["api", "method", "frappe.auth.get_logged_user"], &[])
+            .await
+            .unwrap();
+        assert_eq!(value["message"], "Sample@example.com");
+        let raw = mock.requests.lock().unwrap()[0].to_ascii_lowercase();
+        assert!(raw.starts_with("get /api/method/frappe.auth.get_logged_user "), "{raw}");
+        assert!(raw.contains("authorization: token thekey:thesecret"), "{raw}");
+        assert!(raw.contains("accept: application/json"), "{raw}");
+    }
+
+    #[tokio::test]
+    async fn path_segments_are_percent_encoded_once() {
+        let mock = serve(vec![reply(200, json!({ "data": [] }))]).await;
+        client(&mock)
+            .get(&["api", "resource", "Sales Invoice", "INV/2026-001"], &[("limit_page_length", "0".into())])
+            .await
+            .unwrap();
+        let raw = mock.requests.lock().unwrap()[0].clone();
+        assert!(raw.starts_with("GET /api/resource/Sales%20Invoice/AP%2F2026-001?limit_page_length=0 "), "{raw}");
+    }
+
+    #[tokio::test]
+    async fn retries_429_then_succeeds() {
+        let mut limited = reply(429, json!({ "message": "slow down" }));
+        limited.headers.push(("Retry-After", "0".into()));
+        let mock = serve(vec![limited, reply(200, json!({ "message": "ok" }))]).await;
+        let value = client(&mock).get(&["api", "method", "ping"], &[]).await.unwrap();
+        assert_eq!(value["message"], "ok");
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 2);
+    }
+
+    #[tokio::test]
+    async fn persistent_500_exhausts_the_retries() {
+        let mock = serve(vec![reply(500, json!({ "exception": "frappe.exceptions.ValidationError: boom" }))]).await;
+        let err = client(&mock).get(&["api", "method", "ping"], &[]).await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Server);
+        assert_eq!(err.message, "boom");
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 4, "1 attempt + 3 retries");
+    }
+
+    #[tokio::test]
+    async fn validation_errors_are_not_retried() {
+        let mock = serve(vec![reply(417, json!({ "_error_message": "Rate is required" }))]).await;
+        let err = client(&mock)
+            .post(&["api", "resource", "Sales Invoice"], &json!({ "a": 1 }), true)
+            .await
+            .unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Validation);
+        assert_eq!(err.message, "Rate is required");
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 1);
+    }
+
+    #[tokio::test]
+    async fn timeouts_are_retried_for_reads_but_not_for_ambiguous_writes() {
+        let slow = Reply { delay_ms: 2_000, ..reply(200, json!({})) };
+        let mock = serve(vec![slow]).await;
+        let err = client(&mock).get(&["api", "method", "ping"], &[]).await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Timeout);
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 4);
+
+        let slow = Reply { delay_ms: 2_000, ..reply(200, json!({})) };
+        let mock = serve(vec![slow]).await;
+        let err = client(&mock)
+            .post(&["api", "resource", "Sales Invoice"], &json!({}), false)
+            .await
+            .unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Timeout);
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 1, "a write that may have landed is not repeated");
+    }
+
+    #[tokio::test]
+    async fn non_idempotent_write_retries_429_but_not_500() {
+        let mock = serve(vec![reply(429, json!({})), reply(200, json!({ "data": { "name": "X" } }))]).await;
+        let value = client(&mock)
+            .post(&["api", "resource", "Sales Invoice"], &json!({}), false)
+            .await
+            .unwrap();
+        assert_eq!(value["data"]["name"], "X");
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 2);
+
+        let mock = serve(vec![reply(500, json!({}))]).await;
+        let err = client(&mock)
+            .post(&["api", "resource", "Sales Invoice"], &json!({}), false)
+            .await
+            .unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Server);
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 1);
+    }
+
+    #[tokio::test]
+    async fn redirects_are_reported_not_followed() {
+        let mut moved = reply(301, json!({}));
+        moved.headers.push(("Location", "https://erp.example.com/".into()));
+        let mock = serve(vec![moved]).await;
+        let err = client(&mock).get(&["api", "method", "ping"], &[]).await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Protocol);
+        assert!(err.message.contains("https://erp.example.com/"), "{}", err.message);
+        assert_eq!(mock.hits.load(Ordering::SeqCst), 1);
+    }
+
+    #[tokio::test]
+    async fn html_success_page_is_a_protocol_error() {
+        let mut page = reply(200, json!({}));
+        page.body = "<html>login</html>".into();
+        let mock = serve(vec![page]).await;
+        let err = client(&mock).get(&["api", "method", "ping"], &[]).await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Protocol);
+    }
+
+    #[tokio::test]
+    async fn refused_connection_is_a_network_error_without_the_secret() {
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+        let port = listener.local_addr().unwrap().port();
+        drop(listener);
+        let c = ErpClient::new(&format!("http://127.0.0.1:{port}"), "thekey", &Secret::new("thesecret"), "", fast_opts()).unwrap();
+        let err = c.get(&["api", "method", "ping"], &[]).await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Network);
+        assert!(!err.to_string().contains("thesecret"));
+        assert!(!format!("{c:?}").contains("thesecret"));
+    }
+
+    #[test]
+    fn credentials_are_required_and_a_bad_ca_is_refused() {
+        assert!(ErpClient::new("https://erp.example.com", "", &Secret::new("s"), "", fast_opts()).is_err());
+        assert!(ErpClient::new("https://erp.example.com", "k", &Secret::default(), "", fast_opts()).is_err());
+        let err = ErpClient::new("https://erp.example.com", "k", &Secret::new("s"), "not a certificate", fast_opts()).unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Config);
+    }
+}

src-tauri/src/integrations/erpnext/config.rs

@@ -0,0 +1,562 @@
+//! ERPNext connection and mapping settings (the single `erpnext_config` row).
+//!
+//! The API secret lives in the SQLite DB and is never handed back to the webview: `ErpnextConfigView`
+//! carries only `api_secret_set`. `Secret` redacts itself in `Debug`, so a stray `{:?}` cannot leak it.
+
+use super::client::normalize_base_url;
+use rusqlite::{params, Connection};
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use std::collections::BTreeMap;
+
+/// A credential that never prints itself.
+#[derive(Clone, Default, PartialEq, Eq)]
+pub struct Secret(String);
+
+impl Secret {
+    pub fn new(value: impl Into<String>) -> Self {
+        Secret(value.into())
+    }
+
+    pub fn expose(&self) -> &str {
+        &self.0
+    }
+
+    pub fn is_set(&self) -> bool {
+        !self.0.is_empty()
+    }
+}
+
+impl std::fmt::Debug for Secret {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(if self.is_set() { "Secret([redacted])" } else { "Secret(unset)" })
+    }
+}
+
+/// How the Sales Invoice gets its name in ERPNext.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum NamingMode {
+    /// The Voiced number becomes the document name (API v2, Frappe >= 15.73).
+    Mirror,
+    /// ERPNext assigns its own series number; the Voiced number goes into `remarks`.
+    Series,
+}
+
+impl NamingMode {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            NamingMode::Mirror => "mirror",
+            NamingMode::Series => "series",
+        }
+    }
+
+    pub fn parse(s: &str) -> Result<Self, String> {
+        match s {
+            "mirror" => Ok(NamingMode::Mirror),
+            "series" => Ok(NamingMode::Series),
+            other => Err(format!("Unknown naming mode \"{other}\"")),
+        }
+    }
+}
+
+/// Voiced line unit to ERPNext UOM. Whole-number UOMs such as "Nos" reject fractional quantities,
+/// which is why hours and minutes map to their own UOMs.
+pub fn default_uom_map() -> BTreeMap<String, String> {
+    [
+        ("second", "Second"),
+        ("minute", "Minute"),
+        ("hour", "Hour"),
+        ("session", "Nos"),
+        ("unit", "Nos"),
+    ]
+    .iter()
+    .map(|(k, v)| (k.to_string(), v.to_string()))
+    .collect()
+}
+
+/// Everything stored for the integration, secret included. Backend-only.
+#[derive(Debug, Clone)]
+pub struct ErpnextConfig {
+    pub base_url: String,
+    pub api_key: String,
+    pub api_secret: Secret,
+    pub extra_ca_pem: String,
+    pub company: String,
+    pub company_address: String,
+    pub naming_mode: NamingMode,
+    pub naming_series: String,
+    pub income_account: String,
+    pub cost_center: String,
+    pub cgst_account: String,
+    pub sgst_account: String,
+    pub utgst_account: String,
+    pub igst_account: String,
+    pub tax_template_intra: String,
+    pub tax_template_inter: String,
+    pub payment_bank_account: String,
+    pub tds_account: String,
+    pub default_item_code: String,
+    pub uom_map: BTreeMap<String, String>,
+    pub customer_group: String,
+    pub territory: String,
+    pub selling_price_list: String,
+    pub submit_on_push: bool,
+    pub attach_pdf: bool,
+    pub auto_push_on_issue: bool,
+    pub create_missing_customers: bool,
+    /// JSON of the last connection test (versions, IC flag, warnings); empty if never run. Never holds secrets.
+    pub last_detect_result: String,
+}
+
+impl Default for ErpnextConfig {
+    fn default() -> Self {
+        ErpnextConfig {
+            base_url: String::new(),
+            api_key: String::new(),
+            api_secret: Secret::default(),
+            extra_ca_pem: String::new(),
+            company: String::new(),
+            company_address: String::new(),
+            naming_mode: NamingMode::Mirror,
+            naming_series: String::new(),
+            income_account: String::new(),
+            cost_center: String::new(),
+            cgst_account: String::new(),
+            sgst_account: String::new(),
+            utgst_account: String::new(),
+            igst_account: String::new(),
+            tax_template_intra: String::new(),
+            tax_template_inter: String::new(),
+            payment_bank_account: String::new(),
+            tds_account: String::new(),
+            default_item_code: String::new(),
+            uom_map: default_uom_map(),
+            customer_group: String::new(),
+            territory: String::new(),
+            selling_price_list: String::new(),
+            submit_on_push: false,
+            attach_pdf: true,
+            auto_push_on_issue: false,
+            create_missing_customers: true,
+            last_detect_result: String::new(),
+        }
+    }
+}
+
+impl ErpnextConfig {
+    /// ERPNext UOM for a Voiced unit; falls back to the built-in default, then to "Nos".
+    pub fn uom_for(&self, unit: &str) -> String {
+        if let Some(u) = self.uom_map.get(unit).filter(|u| !u.trim().is_empty()) {
+            return u.trim().to_string();
+        }
+        default_uom_map().remove(unit).unwrap_or_else(|| "Nos".to_string())
+    }
+
+    pub fn view(&self) -> ErpnextConfigView {
+        ErpnextConfigView {
+            base_url: self.base_url.clone(),
+            api_key: self.api_key.clone(),
+            api_secret_set: self.api_secret.is_set(),
+            extra_ca_pem: self.extra_ca_pem.clone(),
+            company: self.company.clone(),
+            company_address: self.company_address.clone(),
+            naming_mode: self.naming_mode,
+            naming_series: self.naming_series.clone(),
+            income_account: self.income_account.clone(),
+            cost_center: self.cost_center.clone(),
+            cgst_account: self.cgst_account.clone(),
+            sgst_account: self.sgst_account.clone(),
+            utgst_account: self.utgst_account.clone(),
+            igst_account: self.igst_account.clone(),
+            tax_template_intra: self.tax_template_intra.clone(),
+            tax_template_inter: self.tax_template_inter.clone(),
+            payment_bank_account: self.payment_bank_account.clone(),
+            tds_account: self.tds_account.clone(),
+            default_item_code: self.default_item_code.clone(),
+            uom_map: self.uom_map.clone(),
+            customer_group: self.customer_group.clone(),
+            territory: self.territory.clone(),
+            selling_price_list: self.selling_price_list.clone(),
+            submit_on_push: self.submit_on_push,
+            attach_pdf: self.attach_pdf,
+            auto_push_on_issue: self.auto_push_on_issue,
+            create_missing_customers: self.create_missing_customers,
+            last_detect_result: serde_json::from_str(&self.last_detect_result).unwrap_or(Value::Null),
+        }
+    }
+}
+
+/// What the webview sees: the same settings minus the secret.
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ErpnextConfigView {
+    pub base_url: String,
+    pub api_key: String,
+    pub api_secret_set: bool,
+    pub extra_ca_pem: String,
+    pub company: String,
+    pub company_address: String,
+    pub naming_mode: NamingMode,
+    pub naming_series: String,
+    pub income_account: String,
+    pub cost_center: String,
+    pub cgst_account: String,
+    pub sgst_account: String,
+    pub utgst_account: String,
+    pub igst_account: String,
+    pub tax_template_intra: String,
+    pub tax_template_inter: String,
+    pub payment_bank_account: String,
+    pub tds_account: String,
+    pub default_item_code: String,
+    pub uom_map: BTreeMap<String, String>,
+    pub customer_group: String,
+    pub territory: String,
+    pub selling_price_list: String,
+    pub submit_on_push: bool,
+    pub attach_pdf: bool,
+    pub auto_push_on_issue: bool,
+    pub create_missing_customers: bool,
+    pub last_detect_result: Value,
+}
+
+/// What the webview sends to save or test. `api_secret` blank keeps the stored secret; a non-blank
+/// value replaces it; `clear_secret` removes it.
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ErpnextConfigInput {
+    #[serde(default)]
+    pub base_url: String,
+    #[serde(default)]
+    pub api_key: String,
+    #[serde(default)]
+    pub api_secret: String,
+    #[serde(default)]
+    pub clear_secret: bool,
+    #[serde(default)]
+    pub extra_ca_pem: String,
+    #[serde(default)]
+    pub company: String,
+    #[serde(default)]
+    pub company_address: String,
+    #[serde(default = "default_naming_mode")]
+    pub naming_mode: String,
+    #[serde(default)]
+    pub naming_series: String,
+    #[serde(default)]
+    pub income_account: String,
+    #[serde(default)]
+    pub cost_center: String,
+    #[serde(default)]
+    pub cgst_account: String,
+    #[serde(default)]
+    pub sgst_account: String,
+    #[serde(default)]
+    pub utgst_account: String,
+    #[serde(default)]
+    pub igst_account: String,
+    #[serde(default)]
+    pub tax_template_intra: String,
+    #[serde(default)]
+    pub tax_template_inter: String,
+    #[serde(default)]
+    pub payment_bank_account: String,
+    #[serde(default)]
+    pub tds_account: String,
+    #[serde(default)]
+    pub default_item_code: String,
+    #[serde(default)]
+    pub uom_map: BTreeMap<String, String>,
+    #[serde(default)]
+    pub customer_group: String,
+    #[serde(default)]
+    pub territory: String,
+    #[serde(default)]
+    pub selling_price_list: String,
+    #[serde(default)]
+    pub submit_on_push: bool,
+    #[serde(default = "yes")]
+    pub attach_pdf: bool,
+    #[serde(default)]
+    pub auto_push_on_issue: bool,
+    #[serde(default = "yes")]
+    pub create_missing_customers: bool,
+    /// None keeps the stored value.
+    #[serde(default)]
+    pub last_detect_result: Option<Value>,
+}
+
+fn default_naming_mode() -> String {
+    "mirror".to_string()
+}
+
+fn yes() -> bool {
+    true
+}
+
+fn origin_of(url: &str) -> String {
+    url.split('/').take(3).collect::<Vec<_>>().join("/").to_ascii_lowercase()
+}
+
+impl ErpnextConfigInput {
+    /// Merges the form values with what is stored: trims, normalises the address, and decides which
+    /// secret applies. The stored secret is never sent to a different server than it was saved for.
+    pub fn resolve(self, stored: &ErpnextConfig) -> Result<ErpnextConfig, String> {
+        let t = |s: &str| s.trim().to_string();
+        let raw_url = self.base_url.trim();
+        let base_url = if raw_url.is_empty() {
+            String::new()
+        } else {
+            normalize_base_url(raw_url).map_err(|e| e.to_string())?
+        };
+        let typed_secret = self.api_secret.trim();
+        let api_secret = if self.clear_secret {
+            Secret::default()
+        } else if !typed_secret.is_empty() {
+            Secret::new(typed_secret)
+        } else {
+            if stored.api_secret.is_set()
+                && !stored.base_url.is_empty()
+                && !base_url.is_empty()
+                && origin_of(&stored.base_url) != origin_of(&base_url)
+            {
+                return Err("The server address changed: enter the API secret again.".into());
+            }
+            stored.api_secret.clone()
+        };
+        let mut uom_map = default_uom_map();
+        for (unit, uom) in &self.uom_map {
+            if !uom.trim().is_empty() {
+                uom_map.insert(unit.trim().to_string(), uom.trim().to_string());
+            }
+        }
+        let last_detect_result = match &self.last_detect_result {
+            Some(Value::Null) => String::new(),
+            Some(v) => v.to_string(),
+            None => stored.last_detect_result.clone(),
+        };
+        Ok(ErpnextConfig {
+            base_url,
+            api_key: t(&self.api_key),
+            api_secret,
+            extra_ca_pem: self.extra_ca_pem.trim().to_string(),
+            company: t(&self.company),
+            company_address: t(&self.company_address),
+            naming_mode: NamingMode::parse(self.naming_mode.trim())?,
+            naming_series: t(&self.naming_series),
+            income_account: t(&self.income_account),
+            cost_center: t(&self.cost_center),
+            cgst_account: t(&self.cgst_account),
+            sgst_account: t(&self.sgst_account),
+            utgst_account: t(&self.utgst_account),
+            igst_account: t(&self.igst_account),
+            tax_template_intra: t(&self.tax_template_intra),
+            tax_template_inter: t(&self.tax_template_inter),
+            payment_bank_account: t(&self.payment_bank_account),
+            tds_account: t(&self.tds_account),
+            default_item_code: t(&self.default_item_code),
+            uom_map,
+            customer_group: t(&self.customer_group),
+            territory: t(&self.territory),
+            selling_price_list: t(&self.selling_price_list),
+            submit_on_push: self.submit_on_push,
+            attach_pdf: self.attach_pdf,
+            auto_push_on_issue: self.auto_push_on_issue,
+            create_missing_customers: self.create_missing_customers,
+            last_detect_result,
+        })
+    }
+}
+
+const SELECT: &str = "SELECT base_url, api_key, api_secret, extra_ca_pem, company, company_address, naming_mode,
+    naming_series, income_account, cost_center, cgst_account, sgst_account, utgst_account, igst_account,
+    tax_template_intra, tax_template_inter, payment_bank_account, tds_account, default_item_code, uom_map,
+    customer_group, territory, selling_price_list, submit_on_push, attach_pdf, auto_push_on_issue,
+    create_missing_customers, last_detect_result FROM erpnext_config WHERE id = 1";
+
+pub fn load(conn: &Connection) -> Result<ErpnextConfig, String> {
+    conn.query_row(SELECT, [], |r| {
+        let naming: String = r.get(6)?;
+        let uom_json: String = r.get(19)?;
+        let mut uom_map = default_uom_map();
+        if let Ok(stored) = serde_json::from_str::<BTreeMap<String, String>>(&uom_json) {
+            uom_map.extend(stored.into_iter().filter(|(_, v)| !v.trim().is_empty()));
+        }
+        Ok(ErpnextConfig {
+            base_url: r.get(0)?,
+            api_key: r.get(1)?,
+            api_secret: Secret::new(r.get::<_, String>(2)?),
+            extra_ca_pem: r.get(3)?,
+            company: r.get(4)?,
+            company_address: r.get(5)?,
+            naming_mode: NamingMode::parse(&naming).unwrap_or(NamingMode::Mirror),
+            naming_series: r.get(7)?,
+            income_account: r.get(8)?,
+            cost_center: r.get(9)?,
+            cgst_account: r.get(10)?,
+            sgst_account: r.get(11)?,
+            utgst_account: r.get(12)?,
+            igst_account: r.get(13)?,
+            tax_template_intra: r.get(14)?,
+            tax_template_inter: r.get(15)?,
+            payment_bank_account: r.get(16)?,
+            tds_account: r.get(17)?,
+            default_item_code: r.get(18)?,
+            uom_map,
+            customer_group: r.get(20)?,
+            territory: r.get(21)?,
+            selling_price_list: r.get(22)?,
+            submit_on_push: r.get::<_, i64>(23)? != 0,
+            attach_pdf: r.get::<_, i64>(24)? != 0,
+            auto_push_on_issue: r.get::<_, i64>(25)? != 0,
+            create_missing_customers: r.get::<_, i64>(26)? != 0,
+            last_detect_result: r.get(27)?,
+        })
+    })
+    .map_err(|e| e.to_string())
+}
+
+pub fn save(conn: &Connection, c: &ErpnextConfig) -> Result<(), String> {
+    let uom_json = serde_json::to_string(&c.uom_map).map_err(|e| e.to_string())?;
+    conn.execute(
+        "UPDATE erpnext_config SET base_url = ?1, api_key = ?2, api_secret = ?3, extra_ca_pem = ?4,
+            company = ?5, company_address = ?6, naming_mode = ?7, naming_series = ?8, income_account = ?9,
+            cost_center = ?10, cgst_account = ?11, sgst_account = ?12, utgst_account = ?13, igst_account = ?14,
+            tax_template_intra = ?15, tax_template_inter = ?16, payment_bank_account = ?17, tds_account = ?18,
+            default_item_code = ?19, uom_map = ?20, customer_group = ?21, territory = ?22,
+            selling_price_list = ?23, submit_on_push = ?24, attach_pdf = ?25, auto_push_on_issue = ?26,
+            create_missing_customers = ?27, last_detect_result = ?28,
+            updated_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
+         WHERE id = 1",
+        params![
+            c.base_url,
+            c.api_key,
+            c.api_secret.expose(),
+            c.extra_ca_pem,
+            c.company,
+            c.company_address,
+            c.naming_mode.as_str(),
+            c.naming_series,
+            c.income_account,
+            c.cost_center,
+            c.cgst_account,
+            c.sgst_account,
+            c.utgst_account,
+            c.igst_account,
+            c.tax_template_intra,
+            c.tax_template_inter,
+            c.payment_bank_account,
+            c.tds_account,
+            c.default_item_code,
+            uom_json,
+            c.customer_group,
+            c.territory,
+            c.selling_price_list,
+            c.submit_on_push as i64,
+            c.attach_pdf as i64,
+            c.auto_push_on_issue as i64,
+            c.create_missing_customers as i64,
+            c.last_detect_result,
+        ],
+    )
+    .map_err(|e| e.to_string())?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn input(extra: serde_json::Value) -> ErpnextConfigInput {
+        let mut base = serde_json::json!({ "baseUrl": "https://erp.example.com/", "apiKey": "key1" });
+        base.as_object_mut().unwrap().extend(extra.as_object().unwrap().clone());
+        serde_json::from_value(base).unwrap()
+    }
+
+    fn db() -> Connection {
+        crate::db::open_in_memory().unwrap()
+    }
+
+    #[test]
+    fn debug_never_prints_the_secret() {
+        let cfg = ErpnextConfig { api_secret: Secret::new("s3cr3t-value"), ..Default::default() };
+        assert!(!format!("{cfg:?}").contains("s3cr3t-value"));
+        assert!(!format!("{:?}", Secret::new("s3cr3t-value")).contains("s3cr3t-value"));
+    }
+
+    #[test]
+    fn defaults_load_from_the_migration_row() {
+        let cfg = load(&db()).unwrap();
+        assert_eq!(cfg.naming_mode, NamingMode::Mirror);
+        assert!(!cfg.submit_on_push && cfg.attach_pdf && !cfg.auto_push_on_issue && cfg.create_missing_customers);
+        assert_eq!(cfg.uom_for("hour"), "Hour");
+        assert_eq!(cfg.uom_for("session"), "Nos");
+        assert!(!cfg.api_secret.is_set());
+    }
+
+    #[test]
+    fn round_trip_keeps_secret_server_side_only() {
+        let conn = db();
+        let stored = load(&conn).unwrap();
+        let cfg = input(serde_json::json!({ "apiSecret": "topsecret", "company": "Test Co", "submitOnPush": true }))
+            .resolve(&stored)
+            .unwrap();
+        save(&conn, &cfg).unwrap();
+
+        let back = load(&conn).unwrap();
+        assert_eq!(back.api_secret.expose(), "topsecret");
+        assert_eq!(back.base_url, "https://erp.example.com");
+        assert_eq!(back.company, "Test Co");
+        assert!(back.submit_on_push);
+
+        let view = serde_json::to_value(back.view()).unwrap();
+        assert_eq!(view["apiSecretSet"], true);
+        assert!(!view.to_string().contains("topsecret"));
+        assert!(view.get("apiSecret").is_none());
+    }
+
+    #[test]
+    fn blank_secret_keeps_and_explicit_values_replace_or_clear() {
+        let conn = db();
+        let first = input(serde_json::json!({ "apiSecret": "one" })).resolve(&load(&conn).unwrap()).unwrap();
+        save(&conn, &first).unwrap();
+
+        let keep = input(serde_json::json!({ "apiSecret": "  " })).resolve(&load(&conn).unwrap()).unwrap();
+        assert_eq!(keep.api_secret.expose(), "one");
+        let replace = input(serde_json::json!({ "apiSecret": "two" })).resolve(&load(&conn).unwrap()).unwrap();
+        assert_eq!(replace.api_secret.expose(), "two");
+        let clear = input(serde_json::json!({ "clearSecret": true })).resolve(&load(&conn).unwrap()).unwrap();
+        assert!(!clear.api_secret.is_set());
+    }
+
+    #[test]
+    fn stored_secret_is_not_reused_for_another_server() {
+        let conn = db();
+        let first = input(serde_json::json!({ "apiSecret": "one" })).resolve(&load(&conn).unwrap()).unwrap();
+        save(&conn, &first).unwrap();
+        let moved = input(serde_json::json!({ "baseUrl": "https://other.example.org" })).resolve(&load(&conn).unwrap());
+        assert!(moved.unwrap_err().contains("API secret"));
+        // The same server with a different path or case is still the same origin.
+        let same = input(serde_json::json!({ "baseUrl": "HTTPS://ERP.example.com" })).resolve(&load(&conn).unwrap());
+        assert!(same.is_ok());
+    }
+
+    #[test]
+    fn invalid_address_or_naming_mode_is_rejected() {
+        let stored = ErpnextConfig::default();
+        assert!(input(serde_json::json!({ "baseUrl": "http://erp.example.com" })).resolve(&stored).is_err());
+        assert!(input(serde_json::json!({ "namingMode": "random" })).resolve(&stored).is_err());
+    }
+
+    #[test]
+    fn uom_map_merges_over_defaults() {
+        let cfg = input(serde_json::json!({ "uomMap": { "hour": "Hr", "unit": "" } }))
+            .resolve(&ErpnextConfig::default())
+            .unwrap();
+        assert_eq!(cfg.uom_for("hour"), "Hr");
+        assert_eq!(cfg.uom_for("unit"), "Nos");
+        assert_eq!(cfg.uom_for("minute"), "Minute");
+        assert_eq!(cfg.uom_for("unheard-of"), "Nos");
+    }
+}

src-tauri/src/integrations/erpnext/discovery.rs

@@ -0,0 +1,861 @@
+//! What the connected site is (versions, India Compliance), the lists the settings dropdowns need, and the
+//! connection test that turns all of it into warnings.
+
+use super::client::ErpClient;
+use super::config::{ErpnextConfig, NamingMode};
+use super::errors::{ErpError, ErrorKind};
+use serde::Serialize;
+use serde_json::{json, Value};
+
+// ---- versions and feature switches ----
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize)]
+pub struct Version {
+    pub major: u32,
+    pub minor: u32,
+    pub patch: u32,
+}
+
+impl Version {
+    /// Parses `15.73.2`, `v16.0.0-dev` or `15.1`; anything after the numeric part is ignored.
+    pub fn parse(s: &str) -> Option<Version> {
+        let s = s.trim().trim_start_matches(['v', 'V']);
+        let numeric: String = s.chars().take_while(|c| c.is_ascii_digit() || *c == '.').collect();
+        let mut parts = numeric.split('.').filter(|p| !p.is_empty());
+        let major = parts.next()?.parse().ok()?;
+        let minor = parts.next().and_then(|p| p.parse().ok()).unwrap_or(0);
+        let patch = parts.next().and_then(|p| p.parse().ok()).unwrap_or(0);
+        Some(Version { major, minor, patch })
+    }
+}
+
+#[derive(Debug, Clone, Default, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ServerVersions {
+    pub frappe: Option<String>,
+    pub erpnext: Option<String>,
+    pub india_compliance: Option<String>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct FeatureSwitches {
+    /// API v2 keeps a posted document name verbatim (Frappe >= 15.73, or 16+).
+    pub v2_naming: bool,
+    /// India Compliance is installed, so the GST header and item fields apply.
+    pub india_compliance: bool,
+}
+
+pub fn feature_switches(v: &ServerVersions) -> FeatureSwitches {
+    let frappe = v.frappe.as_deref().and_then(Version::parse);
+    FeatureSwitches {
+        v2_naming: frappe.is_some_and(|f| (f.major, f.minor) >= (15, 73)),
+        india_compliance: v.india_compliance.is_some(),
+    }
+}
+
+/// Reads `{"message": {"frappe": {"version": "15.73.0"}, ...}}`.
+pub fn parse_versions(value: &Value) -> ServerVersions {
+    let apps = value.get("message").unwrap_or(value);
+    let version_of = |app: &str| -> Option<String> {
+        let entry = apps.get(app)?;
+        let v = entry.get("version").and_then(Value::as_str).or_else(|| entry.as_str())?;
+        let v = v.trim();
+        (!v.is_empty()).then(|| v.to_string())
+    };
+    ServerVersions {
+        frappe: version_of("frappe"),
+        erpnext: version_of("erpnext"),
+        india_compliance: version_of("india_compliance"),
+    }
+}
+
+// ---- number rules (India Compliance) ----
+
+pub const IC_MAX_NUMBER_LEN: usize = 16;
+
+/// India Compliance: `^[^\W_][A-Za-z0-9\-\/]{0,15}$`.
+pub fn ic_number_ok(number: &str) -> bool {
+    let mut chars = number.chars();
+    let Some(first) = chars.next() else { return false };
+    first.is_alphanumeric()
+        && number.chars().count() <= IC_MAX_NUMBER_LEN
+        && chars.all(|c| c.is_ascii_alphanumeric() || c == '-' || c == '/')
+}
+
+/// Length of a number generated from a Frappe naming series such as `SINV-.YY.-.#####`. A series with no
+/// `#` run gets Frappe's default five digits.
+pub fn naming_series_expanded_len(series: &str) -> usize {
+    let mut len = 0;
+    let mut has_digits = false;
+    for part in series.split('.') {
+        if part.is_empty() {
+            continue;
+        }
+        if part.chars().all(|c| c == '#') {
+            len += part.len();
+            has_digits = true;
+            continue;
+        }
+        len += match part {
+            "YY" | "MM" | "DD" => 2,
+            "YYYY" => 4,
+            "FY" => 7,
+            literal => literal.chars().count(),
+        };
+    }
+    if !has_digits {
+        len += 5;
+    }
+    len
+}
+
+// ---- options for the settings dropdowns ----
+
+#[derive(Debug, Clone, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct OptionItem {
+    /// The value to store (the document name).
+    pub name: String,
+    pub label: String,
+    pub detail: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct OptionError {
+    pub list: String,
+    pub message: String,
+}
+
+#[derive(Debug, Clone, Default, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ErpnextOptions {
+    pub companies: Vec<OptionItem>,
+    pub company_addresses: Vec<OptionItem>,
+    pub income_accounts: Vec<OptionItem>,
+    pub tax_accounts: Vec<OptionItem>,
+    pub tax_templates: Vec<OptionItem>,
+    pub naming_series: Vec<OptionItem>,
+    pub item_groups: Vec<OptionItem>,
+    pub uoms: Vec<OptionItem>,
+    pub cost_centers: Vec<OptionItem>,
+    pub price_lists: Vec<OptionItem>,
+    pub customer_groups: Vec<OptionItem>,
+    pub territories: Vec<OptionItem>,
+    /// Lists that could not be loaded (one failing list does not hide the rest).
+    pub errors: Vec<OptionError>,
+}
+
+fn text<'a>(row: &'a Value, key: &str) -> &'a str {
+    row.get(key).and_then(Value::as_str).unwrap_or("").trim()
+}
+
+fn item(row: &Value, label_key: &str, detail: String) -> Option<OptionItem> {
+    let name = text(row, "name");
+    if name.is_empty() {
+        return None;
+    }
+    let label = text(row, label_key);
+    Some(OptionItem {
+        name: name.to_string(),
+        label: if label.is_empty() { name.to_string() } else { label.to_string() },
+        detail,
+    })
+}
+
+fn join(parts: &[&str]) -> String {
+    parts.iter().filter(|p| !p.is_empty()).cloned().collect::<Vec<_>>().join(" · ")
+}
+
+/// Parses the `naming_series` options out of a `getdoctype` response: newline-separated, first line blank.
+pub fn parse_naming_series(doctype_response: &Value) -> Vec<OptionItem> {
+    let docs = doctype_response
+        .get("docs")
+        .or_else(|| doctype_response.get("message").and_then(|m| m.get("docs")))
+        .and_then(Value::as_array);
+    let Some(doc) = docs.and_then(|d| d.first()) else { return Vec::new() };
+    let Some(fields) = doc.get("fields").and_then(Value::as_array) else { return Vec::new() };
+    let Some(field) = fields.iter().find(|f| text(f, "fieldname") == "naming_series") else {
+        return Vec::new();
+    };
+    text(field, "options")
+        .lines()
+        .map(str::trim)
+        .filter(|l| !l.is_empty())
+        .map(|l| OptionItem { name: l.to_string(), label: l.to_string(), detail: format!("e.g. {} digits", naming_series_expanded_len(l)) })
+        .collect()
+}
+
+impl ErpClient {
+    pub async fn get_logged_user(&self) -> Result<String, ErpError> {
+        let v = self.get(&["api", "method", "frappe.auth.get_logged_user"], &[]).await?;
+        let user = v.get("message").and_then(Value::as_str).unwrap_or("").trim().to_string();
+        if user.is_empty() || user.eq_ignore_ascii_case("guest") {
+            return Err(ErpError {
+                kind: ErrorKind::Auth,
+                status: None,
+                message: "The API key and secret were not accepted (the site treated the request as Guest).".into(),
+                exc_type: None,
+            });
+        }
+        Ok(user)
+    }
+
+    pub async fn get_versions(&self) -> Result<ServerVersions, ErpError> {
+        let v = self.get(&["api", "method", "frappe.utils.change_log.get_versions"], &[]).await?;
+        Ok(parse_versions(&v))
+    }
+
+    /// `GET /api/resource/<doctype>` with every row (`limit_page_length=0`).
+    pub async fn list_resource(
+        &self,
+        doctype: &str,
+        fields: &[&str],
+        filters: Value,
+        order_by: &str,
+    ) -> Result<Vec<Value>, ErpError> {
+        let mut query = vec![
+            ("fields", json!(fields).to_string()),
+            ("limit_page_length", "0".to_string()),
+            ("order_by", order_by.to_string()),
+        ];
+        if !filters.is_null() {
+            query.push(("filters", filters.to_string()));
+        }
+        let v = self.get(&["api", "resource", doctype], &query).await?;
+        Ok(v.get("data").and_then(Value::as_array).cloned().unwrap_or_default())
+    }
+
+    pub async fn load_options(&self, company: &str) -> Result<ErpnextOptions, ErpError> {
+        let mut out = ErpnextOptions::default();
+        let company = company.trim();
+
+        macro_rules! load {
+            ($list:literal, $target:expr, $call:expr) => {
+                match $call.await {
+                    Ok(rows) => $target = rows,
+                    Err(e) if matches!(e.kind, ErrorKind::Auth | ErrorKind::Network | ErrorKind::Timeout | ErrorKind::Config | ErrorKind::Protocol) => {
+                        return Err(e)
+                    }
+                    Err(e) => out.errors.push(OptionError { list: $list.to_string(), message: e.to_string() }),
+                }
+            };
+        }
+
+        load!("companies", out.companies, async {
+            self.list_resource("Company", &["name", "company_name", "abbr", "country", "default_currency"], Value::Null, "name asc")
+                .await
+                .map(|rows| {
+                    rows.iter()
+                        .filter_map(|r| item(r, "company_name", join(&[text(r, "abbr"), text(r, "default_currency")])))
+                        .collect()
+                })
+        });
+        load!("itemGroups", out.item_groups, async {
+            self.list_resource("Item Group", &["name"], Value::Null, "name asc")
+                .await
+                .map(|rows| rows.iter().filter_map(|r| item(r, "name", String::new())).collect())
+        });
+        load!("uoms", out.uoms, async {
+            self.list_resource("UOM", &["name"], json!([["enabled", "=", 1]]), "name asc")
+                .await
+                .map(|rows| rows.iter().filter_map(|r| item(r, "name", String::new())).collect())
+        });
+        load!("priceLists", out.price_lists, async {
+            self.list_resource("Price List", &["name"], json!([["enabled", "=", 1], ["selling", "=", 1]]), "name asc")
+                .await
+                .map(|rows| rows.iter().filter_map(|r| item(r, "name", String::new())).collect())
+        });
+        load!("customerGroups", out.customer_groups, async {
+            self.list_resource("Customer Group", &["name"], json!([["is_group", "=", 0]]), "name asc")
+                .await
+                .map(|rows| rows.iter().filter_map(|r| item(r, "name", String::new())).collect())
+        });
+        load!("territories", out.territories, async {
+            self.list_resource("Territory", &["name"], json!([["is_group", "=", 0]]), "name asc")
+                .await
+                .map(|rows| rows.iter().filter_map(|r| item(r, "name", String::new())).collect())
+        });
+        load!("namingSeries", out.naming_series, async {
+            self.get(&["api", "method", "frappe.desk.form.load.getdoctype"], &[("doctype", "Sales Invoice".to_string())])
+                .await
+                .map(|v| parse_naming_series(&v))
+        });
+
+        if company.is_empty() {
+            return Ok(out);
+        }
+        load!("companyAddresses", out.company_addresses, async {
+            let filters = json!([
+                ["Dynamic Link", "link_doctype", "=", "Company"],
+                ["Dynamic Link", "link_name", "=", company],
+                ["disabled", "=", 0]
+            ]);
+            let base = ["name", "address_title", "address_line1", "city", "state", "pincode"];
+            let with_gstin = ["name", "address_title", "address_line1", "city", "state", "pincode", "gstin"];
+            // `gstin` is a custom field added by India Compliance; a plain site rejects it ("Field not permitted").
+            let rows = match self.list_resource("Address", &with_gstin, filters.clone(), "name asc").await {
+                Err(e) if e.kind == ErrorKind::Validation => self.list_resource("Address", &base, filters, "name asc").await?,
+                other => other?,
+            };
+            Ok::<_, ErpError>(
+                rows.iter()
+                    .filter_map(|r| {
+                        item(
+                            r,
+                            "address_title",
+                            join(&[text(r, "address_line1"), text(r, "city"), text(r, "state"), text(r, "pincode"), text(r, "gstin")]),
+                        )
+                    })
+                    .collect(),
+            )
+        });
+        load!("incomeAccounts", out.income_accounts, async {
+            self.list_resource(
+                "Account",
+                &["name", "account_name", "account_type"],
+                json!([["company", "=", company], ["root_type", "=", "Income"], ["is_group", "=", 0], ["disabled", "=", 0]]),
+                "name asc",
+            )
+            .await
+            .map(|rows| rows.iter().filter_map(|r| item(r, "account_name", text(r, "account_type").to_string())).collect())
+        });
+        load!("taxAccounts", out.tax_accounts, async {
+            self.list_resource(
+                "Account",
+                &["name", "account_name", "account_type"],
+                json!([["company", "=", company], ["account_type", "=", "Tax"], ["is_group", "=", 0], ["disabled", "=", 0]]),
+                "name asc",
+            )
+            .await
+            .map(|rows| rows.iter().filter_map(|r| item(r, "account_name", text(r, "account_type").to_string())).collect())
+        });
+        load!("taxTemplates", out.tax_templates, async {
+            self.list_resource(
+                "Sales Taxes and Charges Template",
+                &["name", "title", "is_default"],
+                json!([["company", "=", company], ["disabled", "=", 0]]),
+                "name asc",
+            )
+            .await
+            .map(|rows| rows.iter().filter_map(|r| item(r, "title", String::new())).collect())
+        });
+        load!("costCenters", out.cost_centers, async {
+            self.list_resource(
+                "Cost Center",
+                &["name", "cost_center_name"],
+                json!([["company", "=", company], ["is_group", "=", 0], ["disabled", "=", 0]]),
+                "name asc",
+            )
+            .await
+            .map(|rows| rows.iter().filter_map(|r| item(r, "cost_center_name", String::new())).collect())
+        });
+        Ok(out)
+    }
+}
+
+// ---- connection test and warnings ----
+
+#[derive(Debug, Clone, Serialize, PartialEq, Eq)]
+pub struct Warning {
+    pub code: String,
+    pub message: String,
+}
+
+fn warn(code: &str, message: impl Into<String>) -> Warning {
+    Warning { code: code.to_string(), message: message.into() }
+}
+
+/// Facts from the local database that the warnings need.
+#[derive(Debug, Clone, Default)]
+pub struct LocalFacts {
+    pub vendor_registered: bool,
+    /// Numbers of issued/cancelled invoices that India Compliance would refuse (at most a few examples).
+    pub invalid_numbers: Vec<String>,
+    /// The number the next invoice would get, if a series is active.
+    pub next_number: Option<String>,
+}
+
+/// What was learned from the site. `None` means the check could not run.
+#[derive(Debug, Clone, Default)]
+pub struct RemoteFacts {
+    pub versions: Option<ServerVersions>,
+    pub company_address_count: Option<usize>,
+    /// Rows of GST Settings -> gst_accounts, or the reason they could not be read.
+    pub gst_accounts: Option<Result<Vec<Value>, String>>,
+}
+
+/// Checks that the configured tax accounts appear as Output accounts for the company in GST Settings.
+/// Otherwise India Compliance silently files the items as Nil-Rated.
+pub fn check_gst_accounts(rows: &[Value], cfg: &ErpnextConfig) -> Vec<Warning> {
+    let for_company: Vec<&Value> = rows
+        .iter()
+        .filter(|r| text(r, "company") == cfg.company && matches!(text(r, "account_type"), "" | "Output"))
+        .collect();
+    if for_company.is_empty() {
+        return vec![warn(
+            "gst_accounts_not_configured",
+            format!(
+                "GST accounts are not configured for \"{}\" in GST Settings. India Compliance will file these invoices as Nil-Rated.",
+                cfg.company
+            ),
+        )];
+    }
+    let has = |field: &str, account: &str| for_company.iter().any(|r| text(r, field) == account);
+    let mut out = Vec::new();
+    for (field, label, account) in [
+        ("cgst_account", "CGST", cfg.cgst_account.as_str()),
+        ("sgst_account", "SGST", cfg.sgst_account.as_str()),
+        ("igst_account", "IGST", cfg.igst_account.as_str()),
+    ] {
+        if !account.is_empty() && !has(field, account) {
+            out.push(warn(
+                "gst_account_mismatch",
+                format!("The {label} account \"{account}\" is not the {label} output account in GST Settings; GST returns would not pick the tax up."),
+            ));
+        }
+    }
+    out
+}
+
+/// Pure: turns the configuration and the facts gathered into the list shown after a connection test.
+pub fn build_warnings(cfg: &ErpnextConfig, local: &LocalFacts, remote: &RemoteFacts) -> Vec<Warning> {
+    let mut w = Vec::new();
+    let features = remote.versions.as_ref().map(feature_switches);
+    let ic = features.is_some_and(|f| f.india_compliance);
+
+    if remote.versions.is_none() {
+        w.push(warn(
+            "versions_unknown",
+            "The site's versions could not be read, so India Compliance and API v2 naming were not detected.",
+        ));
+    }
+    if cfg.company.is_empty() {
+        w.push(warn("company_missing", "No company is selected."));
+    }
+    if cfg.income_account.is_empty() {
+        w.push(warn(
+            "income_account_missing",
+            "No income account is set. Rows without an item code need one, and ERPNext has no fallback for them.",
+        ));
+    }
+    if cfg.naming_mode == NamingMode::Mirror {
+        if let Some(f) = features {
+            if !f.v2_naming {
+                w.push(warn(
+                    "mirror_unsupported",
+                    "Mirroring the Voiced number needs Frappe 15.73 or newer. Use the ERPNext series naming mode instead.",
+                ));
+            }
+        }
+    } else if cfg.naming_series.is_empty() {
+        w.push(warn("naming_series_missing", "ERPNext series naming is selected but no naming series is chosen."));
+    }
+
+    if local.vendor_registered {
+        if cfg.cgst_account.is_empty() || cfg.sgst_account.is_empty() || cfg.igst_account.is_empty() {
+            w.push(warn(
+                "tax_accounts_missing",
+                "The supplier is GST-registered but the CGST, SGST and IGST accounts are not all set.",
+            ));
+        }
+        if remote.versions.is_some() && !ic {
+            w.push(warn(
+                "ic_not_detected",
+                "India Compliance is not installed on the site, so the GST fields (place of supply, HSN, GSTIN) will not be sent.",
+            ));
+        }
+    }
+
+    if ic {
+        if local.vendor_registered {
+            match &remote.gst_accounts {
+                Some(Ok(rows)) => w.extend(check_gst_accounts(rows, cfg)),
+                Some(Err(why)) => w.push(warn(
+                    "gst_settings_unreadable",
+                    format!("GST Settings could not be read ({why}), so the GST accounts were not checked."),
+                )),
+                None => {}
+            }
+        }
+        if cfg.company_address.is_empty() {
+            w.push(warn("company_address_missing", "India Compliance needs a company address on every invoice; none is selected."));
+        } else if remote.company_address_count == Some(0) {
+            w.push(warn("company_address_missing", "No address is linked to the company on the site."));
+        }
+        match cfg.naming_mode {
+            NamingMode::Mirror => {
+                if !local.invalid_numbers.is_empty() {
+                    w.push(warn(
+                        "number_invalid",
+                        format!(
+                            "India Compliance allows at most {IC_MAX_NUMBER_LEN} characters (letters, digits, - and /). These numbers do not qualify: {}.",
+                            local.invalid_numbers.join(", ")
+                        ),
+                    ));
+                }
+                if let Some(next) = &local.next_number {
+                    if !ic_number_ok(next) {
+                        w.push(warn(
+                            "number_invalid",
+                            format!("The next invoice number {next} is longer than {IC_MAX_NUMBER_LEN} characters or has characters India Compliance refuses."),
+                        ));
+                    }
+                }
+            }
+            NamingMode::Series => {
+                let len = naming_series_expanded_len(&cfg.naming_series);
+                if !cfg.naming_series.is_empty() && len > IC_MAX_NUMBER_LEN {
+                    w.push(warn(
+                        "naming_series_too_long",
+                        format!(
+                            "The naming series \"{}\" produces numbers of about {len} characters; India Compliance allows {IC_MAX_NUMBER_LEN}.",
+                            cfg.naming_series
+                        ),
+                    ));
+                }
+            }
+        }
+    }
+    w
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ConnectionTest {
+    pub user: String,
+    pub versions: ServerVersions,
+    pub features: FeatureSwitches,
+    /// Same as `features.india_compliance`, for the UI.
+    pub india_compliance: bool,
+    pub warnings: Vec<Warning>,
+}
+
+/// Runs the connection test: identity (a failure here fails the test), versions, then the checks that only
+/// produce warnings.
+pub async fn test_connection(client: &ErpClient, cfg: &ErpnextConfig, local: &LocalFacts) -> Result<ConnectionTest, ErpError> {
+    let user = client.get_logged_user().await?;
+    let versions = match client.get_versions().await {
+        Ok(v) => Some(v),
+        Err(e) if e.kind == ErrorKind::Auth => return Err(e),
+        Err(_) => None,
+    };
+    let mut remote = RemoteFacts { versions, ..Default::default() };
+    let features = remote.versions.as_ref().map(feature_switches);
+    if features.is_some_and(|f| f.india_compliance) {
+        if !cfg.company.is_empty() {
+            remote.company_address_count = client
+                .list_resource(
+                    "Address",
+                    &["name"],
+                    json!([["Dynamic Link", "link_doctype", "=", "Company"], ["Dynamic Link", "link_name", "=", cfg.company], ["disabled", "=", 0]]),
+                    "name asc",
+                )
+                .await
+                .ok()
+                .map(|rows| rows.len());
+        }
+        if local.vendor_registered {
+            remote.gst_accounts = Some(
+                client
+                    .get(&["api", "resource", "GST Settings", "GST Settings"], &[])
+                    .await
+                    .map(|v| v.get("data").and_then(|d| d.get("gst_accounts")).and_then(Value::as_array).cloned().unwrap_or_default())
+                    .map_err(|e| e.to_string()),
+            );
+        }
+    }
+    let warnings = build_warnings(cfg, local, &remote);
+    let versions = remote.versions.unwrap_or_default();
+    let features = feature_switches(&versions);
+    Ok(ConnectionTest { user, india_compliance: features.india_compliance, features, versions, warnings })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn cfg() -> ErpnextConfig {
+        ErpnextConfig {
+            company: "Test Co".into(),
+            company_address: "Test Co-Billing".into(),
+            income_account: "Sales - AC".into(),
+            cgst_account: "Output CGST - AC".into(),
+            sgst_account: "Output SGST - AC".into(),
+            igst_account: "Output IGST - AC".into(),
+            ..Default::default()
+        }
+    }
+
+    fn ic_versions(frappe: &str) -> RemoteFacts {
+        RemoteFacts {
+            versions: Some(ServerVersions {
+                frappe: Some(frappe.into()),
+                erpnext: Some("15.121.6".into()),
+                india_compliance: Some("15.0.0".into()),
+            }),
+            company_address_count: Some(1),
+            gst_accounts: Some(Ok(vec![json!({
+                "company": "Test Co", "account_type": "Output",
+                "cgst_account": "Output CGST - AC", "sgst_account": "Output SGST - AC", "igst_account": "Output IGST - AC"
+            })])),
+        }
+    }
+
+    fn codes(w: &[Warning]) -> Vec<&str> {
+        w.iter().map(|w| w.code.as_str()).collect()
+    }
+
+    #[test]
+    fn versions_parse_leniently() {
+        assert_eq!(Version::parse("15.73.2"), Some(Version { major: 15, minor: 73, patch: 2 }));
+        assert_eq!(Version::parse("v16.0.0-dev"), Some(Version { major: 16, minor: 0, patch: 0 }));
+        assert_eq!(Version::parse("15.1"), Some(Version { major: 15, minor: 1, patch: 0 }));
+        assert_eq!(Version::parse("15.73.0-beta.2"), Some(Version { major: 15, minor: 73, patch: 0 }));
+        assert_eq!(Version::parse("unknown"), None);
+    }
+
+    #[test]
+    fn feature_switches_follow_the_frappe_version_and_ic_presence() {
+        let v = |frappe: &str, ic: bool| ServerVersions {
+            frappe: Some(frappe.into()),
+            erpnext: None,
+            india_compliance: ic.then(|| "15.0.0".into()),
+        };
+        assert!(!feature_switches(&v("15.72.9", false)).v2_naming);
+        assert!(feature_switches(&v("15.73.0", false)).v2_naming);
+        assert!(feature_switches(&v("16.0.0-dev", true)).v2_naming);
+        assert!(feature_switches(&v("16.0.0-dev", true)).india_compliance);
+        assert!(!feature_switches(&ServerVersions::default()).v2_naming);
+    }
+
+    #[test]
+    fn get_versions_response_is_parsed() {
+        let v = parse_versions(&json!({ "message": {
+            "frappe": { "title": "Frappe Framework", "version": "15.73.0" },
+            "erpnext": { "version": "15.121.6" },
+            "india_compliance": { "version": "15.9.0" },
+            "hrms": { "version": "15.0.0" },
+        }}));
+        assert_eq!(v.frappe.as_deref(), Some("15.73.0"));
+        assert_eq!(v.erpnext.as_deref(), Some("15.121.6"));
+        assert_eq!(v.india_compliance.as_deref(), Some("15.9.0"));
+        assert!(parse_versions(&json!({ "message": { "frappe": { "version": "15.0.0" } } })).india_compliance.is_none());
+    }
+
+    #[test]
+    fn india_compliance_number_rule() {
+        for ok in ["INV/2026-001", "A", "1234567890123456", "AP-24-25/0001"] {
+            assert!(ic_number_ok(ok), "{ok}");
+        }
+        for bad in ["", "12345678901234567", "_AB", "AB 01", "AB_01", "-AB", "/AB", "AB#1"] {
+            assert!(!ic_number_ok(bad), "{bad}");
+        }
+    }
+
+    #[test]
+    fn naming_series_is_expanded_before_measuring() {
+        assert_eq!(naming_series_expanded_len("SINV-.YY.-"), 5 + 2 + 1 + 5);
+        assert_eq!(naming_series_expanded_len("ACC-SINV-.YYYY.-.#####"), 9 + 4 + 1 + 5);
+        assert_eq!(naming_series_expanded_len("INV-.MM.-.DD.-.####"), 4 + 2 + 1 + 2 + 1 + 4);
+        assert_eq!(naming_series_expanded_len("LONGPREFIX-ABC-.YYYY.-.#####"), 15 + 4 + 1 + 5);
+    }
+
+    #[test]
+    fn naming_series_options_come_from_getdoctype() {
+        let resp = json!({ "docs": [{ "fields": [
+            { "fieldname": "customer", "options": "Customer" },
+            { "fieldname": "naming_series", "options": "\nSINV-.YY.-\nACC-SINV-.YYYY.-" }
+        ]}]});
+        let items = parse_naming_series(&resp);
+        assert_eq!(items.iter().map(|i| i.name.as_str()).collect::<Vec<_>>(), ["SINV-.YY.-", "ACC-SINV-.YYYY.-"]);
+        assert!(parse_naming_series(&json!({})).is_empty());
+    }
+
+    #[test]
+    fn a_healthy_ic_setup_has_no_warnings() {
+        let local = LocalFacts { vendor_registered: true, invalid_numbers: vec![], next_number: Some("INV/2026-001".into()) };
+        assert_eq!(build_warnings(&cfg(), &local, &ic_versions("15.73.0")), vec![]);
+    }
+
+    #[test]
+    fn gst_accounts_not_configured_or_mismatched_are_flagged() {
+        let local = LocalFacts { vendor_registered: true, ..Default::default() };
+        let mut remote = ic_versions("15.73.0");
+        remote.gst_accounts = Some(Ok(vec![]));
+        assert_eq!(codes(&build_warnings(&cfg(), &local, &remote)), ["gst_accounts_not_configured"]);
+
+        let mut remote = ic_versions("15.73.0");
+        remote.gst_accounts = Some(Ok(vec![json!({ "company": "Test Co", "account_type": "Output",
+            "cgst_account": "Output CGST - AC", "sgst_account": "Other SGST - AC", "igst_account": "Output IGST - AC" })]));
+        let w = build_warnings(&cfg(), &local, &remote);
+        assert_eq!(codes(&w), ["gst_account_mismatch"]);
+        assert!(w[0].message.contains("SGST"));
+
+        let mut remote = ic_versions("15.73.0");
+        remote.gst_accounts = Some(Err("HTTP 403".into()));
+        assert_eq!(codes(&build_warnings(&cfg(), &local, &remote)), ["gst_settings_unreadable"]);
+    }
+
+    #[test]
+    fn long_numbers_and_series_are_flagged_under_ic_only() {
+        let local = LocalFacts {
+            vendor_registered: false,
+            invalid_numbers: vec!["INVOICE/2026/000001".into()],
+            next_number: Some("INVOICE/2026/000002".into()),
+        };
+        let w = build_warnings(&cfg(), &local, &ic_versions("15.73.0"));
+        assert_eq!(codes(&w), ["number_invalid", "number_invalid"]);
+        // Plain ERPNext has no such rule.
+        let mut plain = ic_versions("15.73.0");
+        plain.versions.as_mut().unwrap().india_compliance = None;
+        assert!(build_warnings(&cfg(), &local, &plain).is_empty());
+
+        let mut series = cfg();
+        series.naming_mode = NamingMode::Series;
+        series.naming_series = "LONGPREFIX-ABC-.YYYY.-.#####".into();
+        let w = build_warnings(&series, &LocalFacts::default(), &ic_versions("15.73.0"));
+        assert_eq!(codes(&w), ["naming_series_too_long"]);
+    }
+
+    #[test]
+    fn missing_company_address_and_old_frappe_are_flagged() {
+        let mut c = cfg();
+        c.company_address.clear();
+        let w = build_warnings(&c, &LocalFacts::default(), &ic_versions("15.60.0"));
+        assert_eq!(codes(&w), ["mirror_unsupported", "company_address_missing"]);
+
+        let mut remote = ic_versions("15.73.0");
+        remote.company_address_count = Some(0);
+        assert_eq!(codes(&build_warnings(&cfg(), &LocalFacts::default(), &remote)), ["company_address_missing"]);
+    }
+
+    #[test]
+    fn required_settings_and_unknown_versions_are_flagged() {
+        let w = build_warnings(&ErpnextConfig::default(), &LocalFacts { vendor_registered: true, ..Default::default() }, &RemoteFacts::default());
+        assert_eq!(codes(&w), ["versions_unknown", "company_missing", "income_account_missing", "tax_accounts_missing"]);
+    }
+
+    #[test]
+    fn registered_vendor_without_ic_gets_a_notice() {
+        let mut remote = ic_versions("15.73.0");
+        remote.versions.as_mut().unwrap().india_compliance = None;
+        let w = build_warnings(&cfg(), &LocalFacts { vendor_registered: true, ..Default::default() }, &remote);
+        assert_eq!(codes(&w), ["ic_not_detected"]);
+    }
+
+    // ---- against the mock server ----
+
+    use crate::integrations::erpnext::testutil::{client, reply, serve_fn, Reply};
+
+    fn site(line: &str) -> Reply {
+        let path = line.split_whitespace().nth(1).unwrap_or("");
+        if path.contains("get_logged_user") {
+            reply(200, json!({ "message": "integration@example.com" }))
+        } else if path.contains("get_versions") {
+            reply(200, json!({ "message": {
+                "frappe": { "version": "15.73.0" }, "erpnext": { "version": "15.121.6" }, "india_compliance": { "version": "15.9.0" }
+            }}))
+        } else if path.starts_with("/api/resource/GST%20Settings/GST%20Settings") {
+            reply(200, json!({ "data": { "gst_accounts": [] } }))
+        } else if path.starts_with("/api/resource/Address?") {
+            reply(200, json!({ "data": [
+                { "name": "Test Co-Billing", "address_title": "Test Co", "address_line1": "1 Main Rd", "city": "Mumbai", "state": "Maharashtra", "pincode": "400001", "gstin": "27AAPFU0939F1ZV" }
+            ]}))
+        } else if path.starts_with("/api/resource/Company?") {
+            reply(200, json!({ "data": [{ "name": "Test Co", "company_name": "Test Co", "abbr": "AC", "default_currency": "INR" }] }))
+        } else if path.starts_with("/api/resource/Account?") && path.contains("Income") {
+            reply(200, json!({ "data": [{ "name": "Sales - AC", "account_name": "Sales", "account_type": "" }] }))
+        } else if path.starts_with("/api/resource/Account?") && path.contains("Tax") {
+            reply(200, json!({ "data": [{ "name": "Output CGST - AC", "account_name": "Output CGST", "account_type": "Tax" }] }))
+        } else if path.starts_with("/api/resource/Price%20List?") {
+            reply(403, json!({ "exc_type": "PermissionError", "_error_message": "No permission for Price List" }))
+        } else if path.contains("getdoctype") {
+            reply(200, json!({ "docs": [{ "fields": [{ "fieldname": "naming_series", "options": "\nSINV-.YY.-" }] }] }))
+        } else if path.starts_with("/api/resource/UOM?") {
+            reply(200, json!({ "data": [{ "name": "Nos" }, { "name": "Hour" }, { "name": "" }] }))
+        } else {
+            reply(200, json!({ "data": [] }))
+        }
+    }
+
+    #[tokio::test]
+    async fn connection_test_reports_user_versions_ic_and_warnings() {
+        let mock = serve_fn(|_, line| site(line)).await;
+        let local = LocalFacts { vendor_registered: true, next_number: Some("INV/2026-001".into()), ..Default::default() };
+        let result = test_connection(&client(&mock), &cfg(), &local).await.unwrap();
+        assert_eq!(result.user, "integration@example.com");
+        assert_eq!(result.versions.frappe.as_deref(), Some("15.73.0"));
+        assert!(result.india_compliance && result.features.v2_naming);
+        assert_eq!(codes(&result.warnings), ["gst_accounts_not_configured"]);
+        let json = serde_json::to_value(&result).unwrap();
+        assert_eq!(json["indiaCompliance"], true);
+        assert_eq!(json["features"]["v2Naming"], true);
+    }
+
+    #[tokio::test]
+    async fn company_addresses_fall_back_when_the_site_has_no_gstin_field() {
+        // A plain ERPNext (no India Compliance) rejects the custom `gstin` field with a 417.
+        let mock = serve_fn(|_, line| {
+            let path = line.split_whitespace().nth(1).unwrap_or("");
+            if path.starts_with("/api/resource/Address?") && path.contains("gstin") {
+                reply(417, json!({ "exc_type": "ValidationError", "_error_message": "Field not permitted in query: gstin" }))
+            } else if path.starts_with("/api/resource/Address?") {
+                reply(200, json!({ "data": [{ "name": "Test Co-Billing", "address_title": "Test Co", "address_line1": "1 Main Rd", "city": "Mumbai", "state": "Maharashtra", "pincode": "400001" }] }))
+            } else {
+                reply(200, json!({ "data": [] }))
+            }
+        })
+        .await;
+        let options = client(&mock).load_options("Test Co").await.unwrap();
+        assert_eq!(options.company_addresses.len(), 1);
+        assert_eq!(options.company_addresses[0].name, "Test Co-Billing");
+        assert!(options.errors.iter().all(|e| e.list != "companyAddresses"), "{:?}", options.errors);
+    }
+
+    #[tokio::test]
+    async fn connection_test_fails_for_the_guest_user_and_bad_credentials() {
+        let mock = serve_fn(|_, _| reply(200, json!({ "message": "Guest" }))).await;
+        let err = test_connection(&client(&mock), &cfg(), &LocalFacts::default()).await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Auth);
+
+        let mock = serve_fn(|_, _| reply(401, json!({ "message": "Invalid Authorization" }))).await;
+        let err = test_connection(&client(&mock), &cfg(), &LocalFacts::default()).await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Auth);
+        assert!(!err.to_string().contains("thesecret"));
+    }
+
+    #[tokio::test]
+    async fn options_load_per_list_and_one_failure_does_not_hide_the_rest() {
+        let mock = serve_fn(|_, line| site(line)).await;
+        let options = client(&mock).load_options("Test Co").await.unwrap();
+        assert_eq!(options.companies.len(), 1);
+        assert_eq!(options.companies[0].name, "Test Co");
+        assert_eq!(options.companies[0].detail, "AC · INR");
+        assert_eq!(options.company_addresses[0].name, "Test Co-Billing");
+        assert!(options.company_addresses[0].detail.contains("Mumbai"));
+        assert_eq!(options.income_accounts[0].name, "Sales - AC");
+        assert_eq!(options.tax_accounts[0].name, "Output CGST - AC");
+        assert_eq!(options.naming_series[0].name, "SINV-.YY.-");
+        assert_eq!(options.uoms.iter().map(|u| u.name.as_str()).collect::<Vec<_>>(), ["Nos", "Hour"]);
+        assert!(options.price_lists.is_empty());
+        assert_eq!(options.errors.len(), 1);
+        assert_eq!(options.errors[0].list, "priceLists");
+        assert!(options.errors[0].message.contains("No permission for Price List"));
+
+        // Company-scoped lists are skipped until a company is chosen.
+        let none = client(&mock).load_options("  ").await.unwrap();
+        assert!(none.income_accounts.is_empty() && none.company_addresses.is_empty());
+        let requests = mock.requests.lock().unwrap().join("\n");
+        assert!(requests.contains("root_type"), "income accounts are filtered by root type");
+        assert!(requests.contains("limit_page_length=0"));
+    }
+
+    #[tokio::test]
+    async fn options_abort_on_authentication_failure() {
+        let mock = serve_fn(|_, _| reply(401, json!({ "message": "bad" }))).await;
+        let err = client(&mock).load_options("Test Co").await.unwrap_err();
+        assert_eq!(err.kind, ErrorKind::Auth);
+        assert_eq!(mock.hits.load(std::sync::atomic::Ordering::SeqCst), 1, "stops at the first auth failure");
+    }
+}

src-tauri/src/integrations/erpnext/errors.rs

@@ -0,0 +1,427 @@
+//! Turning Frappe/ERPNext error responses into one readable message plus a machine-usable kind.
+
+use serde::Serialize;
+use serde_json::Value;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "snake_case")]
+pub enum ErrorKind {
+    /// 401: wrong key/secret.
+    Auth,
+    /// 403: the user lacks a role or permission.
+    Permission,
+    NotFound,
+    /// 409 (or a `DuplicateEntryError`): the document already exists.
+    Duplicate,
+    /// 417 and other 4xx data rejections.
+    Validation,
+    RateLimit,
+    Server,
+    Timeout,
+    Network,
+    /// A setting is missing or invalid; nothing was sent.
+    Config,
+    /// The server answered, but not like a Frappe site.
+    Protocol,
+    /// The remote document exists with different data; Voiced never overwrites it.
+    Conflict,
+    /// Voiced refused before sending anything (a draft or cancelled invoice, an unsubmitted parent, bad local data).
+    Precondition,
+    Other,
+}
+
+impl ErrorKind {
+    fn label(self) -> &'static str {
+        match self {
+            ErrorKind::Auth => "Authentication failed",
+            ErrorKind::Permission => "Permission denied",
+            ErrorKind::NotFound => "Not found",
+            ErrorKind::Duplicate => "Already exists",
+            ErrorKind::Validation => "ERPNext rejected the data",
+            ErrorKind::RateLimit => "Rate limited",
+            ErrorKind::Server => "ERPNext server error",
+            ErrorKind::Timeout
+            | ErrorKind::Network
+            | ErrorKind::Config
+            | ErrorKind::Protocol
+            | ErrorKind::Conflict
+            | ErrorKind::Precondition => "",
+            ErrorKind::Other => "Request failed",
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ErpError {
+    pub kind: ErrorKind,
+    pub status: Option<u16>,
+    pub message: String,
+    /// Frappe exception class (e.g. `DuplicateEntryError`) when the server named one.
+    pub exc_type: Option<String>,
+}
+
+impl std::fmt::Display for ErpError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let label = self.kind.label();
+        match (label.is_empty(), self.status) {
+            (true, _) => f.write_str(&self.message),
+            (false, Some(status)) => write!(f, "{label} (HTTP {status}): {}", self.message),
+            (false, None) => write!(f, "{label}: {}", self.message),
+        }
+    }
+}
+
+impl std::error::Error for ErpError {}
+
+impl From<ErpError> for String {
+    fn from(e: ErpError) -> String {
+        e.to_string()
+    }
+}
+
+impl ErpError {
+    pub fn new(kind: ErrorKind, message: impl Into<String>) -> Self {
+        ErpError { kind, status: None, message: message.into(), exc_type: None }
+    }
+
+    pub fn config(message: impl Into<String>) -> Self {
+        Self::new(ErrorKind::Config, message)
+    }
+
+    pub fn protocol(message: impl Into<String>) -> Self {
+        Self::new(ErrorKind::Protocol, message)
+    }
+
+    /// Builds the error for a non-2xx response.
+    pub fn from_response(status: u16, body: &str) -> Self {
+        let parsed = parse_error_body(body);
+        let mut kind = kind_for_status(status);
+        if parsed.exc_type.as_deref() == Some("DuplicateEntryError") {
+            kind = ErrorKind::Duplicate;
+        }
+        let message = parsed.message.unwrap_or_else(|| default_status_text(status));
+        ErpError { kind, status: Some(status), message, exc_type: parsed.exc_type }
+    }
+
+    /// Removes every occurrence of the given secrets from the message.
+    pub fn redacted(mut self, secrets: &[&str]) -> Self {
+        for s in secrets.iter().filter(|s| s.len() >= 4) {
+            self.message = self.message.replace(s, "[redacted]");
+        }
+        self
+    }
+}
+
+pub fn kind_for_status(status: u16) -> ErrorKind {
+    match status {
+        401 => ErrorKind::Auth,
+        403 => ErrorKind::Permission,
+        404 => ErrorKind::NotFound,
+        409 => ErrorKind::Duplicate,
+        429 => ErrorKind::RateLimit,
+        400 | 417 | 422 => ErrorKind::Validation,
+        500..=599 => ErrorKind::Server,
+        _ => ErrorKind::Other,
+    }
+}
+
+fn default_status_text(status: u16) -> String {
+    let reason = reqwest::StatusCode::from_u16(status)
+        .ok()
+        .and_then(|s| s.canonical_reason())
+        .unwrap_or("unexpected response");
+    format!("HTTP {status} {reason}")
+}
+
+#[derive(Debug, Default, PartialEq, Eq)]
+pub struct ParsedError {
+    pub message: Option<String>,
+    pub exc_type: Option<String>,
+}
+
+const MAX_MESSAGE_CHARS: usize = 600;
+
+/// Extracts the human message from a Frappe error body.
+///
+/// v2 puts `errors[]` first. v1 uses `_server_messages` (a JSON string holding a list of JSON strings,
+/// each usually an object with an HTML `message`), then `_error_message`, then `exception` (with the
+/// `frappe.exceptions.X: ` prefix dropped), then `exc_type`. A body that is not JSON (an nginx 502 page)
+/// yields its stripped text, or nothing when that is empty.
+pub fn parse_error_body(body: &str) -> ParsedError {
+    let Ok(json) = serde_json::from_str::<Value>(body) else {
+        let text = strip_html(body);
+        let first = text.lines().find(|l| !l.trim().is_empty()).unwrap_or("").trim();
+        return ParsedError { message: non_empty(truncate(first)), exc_type: None };
+    };
+    let Some(obj) = json.as_object() else {
+        return ParsedError::default();
+    };
+
+    let mut exc_type = obj.get("exc_type").and_then(Value::as_str).map(str::to_string);
+    let mut messages: Vec<String> = Vec::new();
+
+    if let Some(errors) = obj.get("errors").and_then(Value::as_array) {
+        for e in errors {
+            match e {
+                Value::String(s) => push_unique(&mut messages, strip_html(s)),
+                Value::Object(o) => {
+                    let text = o.get("message").and_then(Value::as_str).map(strip_html).filter(|m| !m.is_empty());
+                    let exception = o.get("exception").and_then(Value::as_str).map(split_exception);
+                    if exc_type.is_none() {
+                        exc_type = o
+                            .get("type")
+                            .and_then(Value::as_str)
+                            .map(str::to_string)
+                            .or_else(|| exception.as_ref().and_then(|(t, _)| t.clone()));
+                    }
+                    if let Some(m) = text.or_else(|| exception.map(|(_, m)| m).filter(|m| !m.is_empty())) {
+                        push_unique(&mut messages, m);
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+
+    if messages.is_empty() {
+        if let Some(raw) = obj.get("_server_messages").and_then(Value::as_str) {
+            for m in server_messages(raw) {
+                push_unique(&mut messages, m);
+            }
+        }
+    }
+    if messages.is_empty() {
+        if let Some(m) = obj.get("_error_message").and_then(Value::as_str).map(strip_html).filter(|m| !m.is_empty()) {
+            messages.push(m);
+        }
+    }
+    if messages.is_empty() {
+        if let Some(raw) = obj.get("exception").and_then(Value::as_str) {
+            let (ty, msg) = split_exception(raw);
+            if exc_type.is_none() {
+                exc_type = ty;
+            }
+            if !msg.is_empty() {
+                messages.push(msg);
+            }
+        }
+    }
+    if messages.is_empty() {
+        if let Some(m) = obj.get("message").and_then(Value::as_str).map(strip_html).filter(|m| !m.is_empty()) {
+            messages.push(m);
+        }
+    }
+    if messages.is_empty() {
+        if let Some(t) = &exc_type {
+            messages.push(t.clone());
+        }
+    }
+    if exc_type.is_none() {
+        // v1 on Frappe 14 has no `exc_type`; the class is still named in `exception`.
+        exc_type = obj.get("exception").and_then(Value::as_str).and_then(|e| split_exception(e).0);
+    }
+
+    ParsedError { message: non_empty(truncate(&messages.join("; "))), exc_type }
+}
+
+fn server_messages(raw: &str) -> Vec<String> {
+    let Ok(Value::Array(items)) = serde_json::from_str::<Value>(raw) else {
+        return Vec::new();
+    };
+    items
+        .iter()
+        .filter_map(|item| {
+            let text = match item {
+                Value::String(s) => match serde_json::from_str::<Value>(s) {
+                    Ok(Value::Object(o)) => o.get("message").and_then(Value::as_str).unwrap_or("").to_string(),
+                    _ => s.clone(),
+                },
+                Value::Object(o) => o.get("message").and_then(Value::as_str).unwrap_or("").to_string(),
+                _ => String::new(),
+            };
+            let text = strip_html(&text);
+            (!text.is_empty()).then_some(text)
+        })
+        .collect()
+}
+
+/// Splits `frappe.exceptions.ValidationError: Row 1: bad` into (`ValidationError`, `Row 1: bad`).
+/// A string without a dotted-identifier prefix is returned whole.
+fn split_exception(raw: &str) -> (Option<String>, String) {
+    let first_line = raw.trim().lines().next().unwrap_or("").trim();
+    if let Some((prefix, rest)) = first_line.split_once(": ") {
+        let class_like = prefix.contains('.') || prefix.ends_with("Error") || prefix.ends_with("Exception");
+        if class_like && prefix.chars().all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '.') {
+            let ty = prefix.rsplit('.').next().map(str::to_string);
+            return (ty, strip_html(rest));
+        }
+    }
+    if !first_line.is_empty()
+        && first_line.chars().all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '.')
+        && first_line.contains('.')
+    {
+        // `frappe.exceptions.DoesNotExistError` with no message.
+        return (first_line.rsplit('.').next().map(str::to_string), String::new());
+    }
+    (None, strip_html(first_line))
+}
+
+fn push_unique(list: &mut Vec<String>, text: String) {
+    if !text.is_empty() && !list.contains(&text) {
+        list.push(text);
+    }
+}
+
+fn non_empty(s: String) -> Option<String> {
+    (!s.is_empty()).then_some(s)
+}
+
+fn truncate(s: &str) -> String {
+    if s.chars().count() <= MAX_MESSAGE_CHARS {
+        return s.to_string();
+    }
+    let cut: String = s.chars().take(MAX_MESSAGE_CHARS).collect();
+    format!("{cut}...")
+}
+
+/// Drops tags, decodes the common entities and collapses whitespace.
+pub fn strip_html(input: &str) -> String {
+    let mut out = String::with_capacity(input.len());
+    let mut in_tag = false;
+    let mut tag = String::new();
+    for ch in input.chars() {
+        match ch {
+            '<' => {
+                in_tag = true;
+                tag.clear();
+            }
+            '>' if in_tag => {
+                in_tag = false;
+                let name = tag.trim_start_matches('/').split_whitespace().next().unwrap_or("").to_ascii_lowercase();
+                if matches!(name.as_str(), "br" | "p" | "div" | "li" | "tr" | "h1" | "h2" | "h3") {
+                    out.push('\n');
+                }
+            }
+            _ if in_tag => tag.push(ch),
+            _ => out.push(ch),
+        }
+    }
+    let decoded = out
+        .replace("&nbsp;", " ")
+        .replace("&lt;", "<")
+        .replace("&gt;", ">")
+        .replace("&quot;", "\"")
+        .replace("&#39;", "'")
+        .replace("&#x27;", "'")
+        .replace("&amp;", "&");
+    decoded
+        .lines()
+        .map(|l| l.split_whitespace().collect::<Vec<_>>().join(" "))
+        .filter(|l| !l.is_empty())
+        .collect::<Vec<_>>()
+        .join("\n")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn v1_server_messages_are_double_encoded_and_html_is_stripped() {
+        let inner1 = json!({ "message": "<b>Row 1</b>: Account <i>Sales</i> &amp; more", "indicator": "red" }).to_string();
+        let inner2 = json!({ "message": "Second <br> problem" }).to_string();
+        let server_messages = serde_json::to_string(&vec![inner1, inner2]).unwrap();
+        let body = json!({
+            "exc_type": "ValidationError",
+            "exception": "frappe.exceptions.ValidationError: ignored because messages exist",
+            "_server_messages": server_messages,
+        })
+        .to_string();
+        let parsed = parse_error_body(&body);
+        assert_eq!(parsed.message.as_deref(), Some("Row 1: Account Sales & more; Second\nproblem"));
+        assert_eq!(parsed.exc_type.as_deref(), Some("ValidationError"));
+        let err = ErpError::from_response(417, &body);
+        assert_eq!(err.kind, ErrorKind::Validation);
+        assert_eq!(err.status, Some(417));
+    }
+
+    #[test]
+    fn v1_falls_back_to_error_message_then_exception_then_exc_type() {
+        let a = parse_error_body(&json!({ "_error_message": "Not <b>permitted</b>" }).to_string());
+        assert_eq!(a.message.as_deref(), Some("Not permitted"));
+
+        let b = parse_error_body(
+            &json!({ "exception": "frappe.exceptions.DuplicateEntryError: Sales Invoice INV/1 already exists" }).to_string(),
+        );
+        assert_eq!(b.message.as_deref(), Some("Sales Invoice INV/1 already exists"));
+        assert_eq!(b.exc_type.as_deref(), Some("DuplicateEntryError"));
+
+        let c = parse_error_body(&json!({ "exc_type": "PermissionError" }).to_string());
+        assert_eq!(c.message.as_deref(), Some("PermissionError"));
+    }
+
+    #[test]
+    fn exception_prefix_is_only_dropped_when_it_looks_like_a_class_path() {
+        let parsed = parse_error_body(&json!({ "exception": "Something: with a colon but no class" }).to_string());
+        assert_eq!(parsed.message.as_deref(), Some("Something: with a colon but no class"));
+        assert_eq!(parsed.exc_type, None);
+    }
+
+    #[test]
+    fn v2_errors_array_is_joined() {
+        let body = json!({
+            "errors": [
+                { "type": "ValidationError", "message": "Customer <b>X</b> is disabled", "exception": "frappe.exceptions.ValidationError: x" },
+                { "type": "ValidationError", "exception": "frappe.exceptions.ValidationError: Row 2: rate missing" },
+            ]
+        })
+        .to_string();
+        let parsed = parse_error_body(&body);
+        assert_eq!(parsed.message.as_deref(), Some("Customer X is disabled; Row 2: rate missing"));
+        assert_eq!(parsed.exc_type.as_deref(), Some("ValidationError"));
+    }
+
+    #[test]
+    fn non_json_bodies_use_stripped_text_or_status() {
+        let html = "<html><body><h1>502 Bad Gateway</h1><hr>nginx</body></html>";
+        let err = ErpError::from_response(502, html);
+        assert_eq!(err.kind, ErrorKind::Server);
+        assert_eq!(err.message, "502 Bad Gateway");
+
+        let empty = ErpError::from_response(503, "");
+        assert_eq!(empty.message, "HTTP 503 Service Unavailable");
+    }
+
+    #[test]
+    fn statuses_map_to_kinds() {
+        for (status, kind) in [
+            (401, ErrorKind::Auth),
+            (403, ErrorKind::Permission),
+            (404, ErrorKind::NotFound),
+            (409, ErrorKind::Duplicate),
+            (417, ErrorKind::Validation),
+            (429, ErrorKind::RateLimit),
+            (500, ErrorKind::Server),
+            (502, ErrorKind::Server),
+            (418, ErrorKind::Other),
+        ] {
+            assert_eq!(ErpError::from_response(status, "").kind, kind, "status {status}");
+        }
+        // The exception class wins when the status is generic.
+        let dup = ErpError::from_response(417, &json!({ "exc_type": "DuplicateEntryError" }).to_string());
+        assert_eq!(dup.kind, ErrorKind::Duplicate);
+    }
+
+    #[test]
+    fn secrets_are_redacted_from_messages() {
+        let err = ErpError::new(ErrorKind::Other, "bad token abc123:topsecret in header").redacted(&["topsecret", "abc123"]);
+        assert_eq!(err.message, "bad token [redacted]:[redacted] in header");
+    }
+
+    #[test]
+    fn display_carries_the_status_and_hint() {
+        let err = ErpError::from_response(401, &json!({ "message": "Invalid credentials" }).to_string());
+        assert_eq!(err.to_string(), "Authentication failed (HTTP 401): Invalid credentials");
+    }
+}

src-tauri/src/integrations/erpnext/live_tests.rs

@@ -0,0 +1,755 @@
+//! Live tests against a real ERPNext site. All `#[ignore]`d: they need the stack from
+//! `scripts/erpnext-e2e/README.md` and these environment variables (the setup script prints them):
+//!
+//! - `ERPNEXT_URL`, `ERPNEXT_KEY`, `ERPNEXT_SECRET`: the integration user's credentials;
+//! - `ERPNEXT_COMPANY` (default `Voiced Test Co`) and `ERPNEXT_ABBR` (default `VTC`): the company and its
+//!   abbreviation, from which the account names (`Sales - VTC`, `Output Tax CGST - VTC` ...) are derived;
+//! - `ERPNEXT_IC=1` when the site has India Compliance (enables the IC-only tests).
+//!
+//! Run: `cargo test --manifest-path src-tauri/Cargo.toml live_ -- --ignored --test-threads=1`.
+//! Every test makes its own invoice series (unique prefix per run), so repeated runs never collide.
+
+use super::client::{ClientOptions, ErpClient};
+use super::config::{self, ErpnextConfig, NamingMode, Secret};
+use super::errors::ErrorKind;
+use super::discovery::{test_connection, ConnectionTest, LocalFacts};
+use super::push::{push_invoice, push_payment, PushResult};
+use crate::commands::invoice::{get_invoice_impl, issue_invoice_impl};
+use crate::commands::payments::{record_payment_impl, PaymentInput};
+use crate::commands::series::start_new_series_impl;
+use crate::models::{Invoice, InvoiceInput};
+use rusqlite::params;
+use serde_json::{json, Value};
+use sha2::{Digest, Sha256};
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Mutex;
+
+const VENDOR_GSTIN: &str = "27AAPFU0939F1ZV";
+const KA_GSTIN: &str = "29AABCU9603R1ZJ";
+
+static COUNTER: AtomicUsize = AtomicUsize::new(0);
+
+fn env(name: &str) -> String {
+    std::env::var(name).unwrap_or_else(|_| panic!("set {name} (see scripts/erpnext-e2e/README.md)"))
+}
+
+fn env_or(name: &str, default: &str) -> String {
+    std::env::var(name).unwrap_or_else(|_| default.to_string())
+}
+
+fn base36(mut n: u64, width: usize) -> String {
+    const DIGITS: &[u8] = b"0123456789abcdefghijklmnopqrstuvwxyz";
+    let mut out = vec![b'0'; width];
+    for slot in out.iter_mut().rev() {
+        *slot = DIGITS[(n % 36) as usize];
+        n /= 36;
+    }
+    String::from_utf8(out).unwrap()
+}
+
+struct Live {
+    db: Mutex<rusqlite::Connection>,
+    dir: tempfile::TempDir,
+    http: ErpClient,
+    abbr: String,
+    ic: bool,
+    prefix: String,
+}
+
+impl Live {
+    async fn new(edit: impl FnOnce(&mut ErpnextConfig)) -> Live {
+        let abbr = env_or("ERPNEXT_ABBR", "VTC");
+        let company = env_or("ERPNEXT_COMPANY", "Voiced Test Co");
+        let ic = env_or("ERPNEXT_IC", "0") == "1";
+        let mut cfg = ErpnextConfig {
+            base_url: env("ERPNEXT_URL"),
+            api_key: env("ERPNEXT_KEY"),
+            api_secret: Secret::new(env("ERPNEXT_SECRET")),
+            company_address: format!("{company}-Billing"),
+            company,
+            income_account: format!("Sales - {abbr}"),
+            cgst_account: format!("Output Tax CGST - {abbr}"),
+            sgst_account: format!("Output Tax SGST - {abbr}"),
+            utgst_account: format!("Output Tax UTGST - {abbr}"),
+            igst_account: format!("Output Tax IGST - {abbr}"),
+            cost_center: format!("Main - {abbr}"),
+            tds_account: format!("TDS Receivable - {abbr}"),
+            payment_bank_account: env_or("ERPNEXT_BANK_ACCOUNT", &format!("HDFC - {abbr}")),
+            ..Default::default()
+        };
+        edit(&mut cfg);
+        let http = ErpClient::new(&cfg.base_url, &cfg.api_key, &cfg.api_secret, "", ClientOptions::default()).unwrap();
+
+        let mut conn = crate::db::open_in_memory().unwrap();
+        conn.execute(
+            "UPDATE app_settings SET gst_registration = 'regular', vendor_gstin = ?1,
+             vendor_state_code = '27', vendor_pan = 'AAPFU0939F', default_tax_type = 'cgst_sgst'",
+            [VENDOR_GSTIN],
+        )
+        .unwrap();
+        for (name, gstin, state, line1, city, pin, category) in [
+            ("Voiced Live Intra Co", "", "27", "5 FC Road", "Pune", "411004", "unregistered"),
+            ("Voiced Live Inter Co", KA_GSTIN, "29", "12 MG Road", "Bengaluru", "560001", "registered_regular"),
+        ] {
+            conn.execute(
+                "INSERT INTO clients (name, address, gstin, state_code, address_line1, city, pincode, gst_category, created_at)
+                 VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, 'now')",
+                params![name, line1, gstin, state, line1, city, pin, category],
+            )
+            .unwrap();
+        }
+        let nanos = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos() as u64;
+        let prefix = format!("L{}{}/", base36(nanos / 1_000_000, 4), base36(COUNTER.fetch_add(1, Ordering::SeqCst) as u64, 1));
+        start_new_series_impl(&mut conn, &prefix, 3).unwrap();
+        config::save(&conn, &cfg).unwrap();
+
+        let live = Live { db: Mutex::new(conn), dir: tempfile::tempdir().unwrap(), http, abbr, ic, prefix };
+        // The same step the UI performs before the first push.
+        let ct = live.connection_test(&cfg).await;
+        let mut cfg = cfg;
+        cfg.last_detect_result = serde_json::to_string(&ct).unwrap();
+        config::save(&live.db.lock().unwrap(), &cfg).unwrap();
+        live
+    }
+
+    async fn connection_test(&self, cfg: &ErpnextConfig) -> ConnectionTest {
+        let local = LocalFacts { vendor_registered: true, ..Default::default() };
+        test_connection(&self.http, cfg, &local).await.expect("connection test")
+    }
+
+    fn cfg(&self) -> ErpnextConfig {
+        config::load(&self.db.lock().unwrap()).unwrap()
+    }
+
+    fn save_cfg(&self, edit: impl FnOnce(&mut ErpnextConfig)) {
+        let mut cfg = self.cfg();
+        edit(&mut cfg);
+        config::save(&self.db.lock().unwrap(), &cfg).unwrap();
+    }
+
+    fn preset(&self, description: &str, code: &str) {
+        self.db
+            .lock()
+            .unwrap()
+            .execute(
+                "INSERT INTO item_presets (description, hsn_sac, mode, unit, rate_paise, sort_order, created_at, erpnext_item_code)
+                 VALUES (?1, '', 'fixed', 'unit', 0, 0, 'now', ?2)",
+                params![description, code],
+            )
+            .unwrap();
+    }
+
+    /// Issues an invoice for one of the two live clients. `extra` overrides input fields.
+    fn issue(&self, intra: bool, items: Value, extra: Value) -> Invoice {
+        let (client_id, name, pos, tax_type, gstin) = if intra {
+            (1, "Voiced Live Intra Co", "27", "cgst_sgst", "")
+        } else {
+            (2, "Voiced Live Inter Co", "29", "igst", KA_GSTIN)
+        };
+        let mut input = json!({
+            "invoiceDate": "2026-06-15",
+            "dueDate": "2026-07-15",
+            "clientId": client_id,
+            "clientName": name,
+            "clientGstin": gstin,
+            "placeOfSupplyStateCode": pos,
+            "taxType": tax_type,
+            "taxRate": 18.0,
+            "items": items,
+        });
+        for (k, v) in extra.as_object().unwrap() {
+            input[k] = v.clone();
+        }
+        let input: InvoiceInput = serde_json::from_value(input).unwrap();
+        let mut conn = self.db.lock().unwrap();
+        let inv = issue_invoice_impl(&mut conn, self.dir.path(), input, &json!({})).unwrap();
+        get_invoice_impl(&conn, inv.id).unwrap()
+    }
+
+    /// Puts a small PDF in the archive and records its hash, as exporting the invoice would.
+    fn archive(&self, inv: &Invoice) {
+        let bytes = minimal_pdf(&inv.number);
+        let sha = format!("{:x}", Sha256::digest(&bytes));
+        let dir = self.dir.path().join("archive");
+        std::fs::create_dir_all(&dir).unwrap();
+        std::fs::write(dir.join(format!("{sha}.pdf")), &bytes).unwrap();
+        self.db
+            .lock()
+            .unwrap()
+            .execute("UPDATE invoices SET archived_pdf_sha256 = ?1 WHERE id = ?2", params![sha, inv.id])
+            .unwrap();
+    }
+
+    async fn push(&self, inv: &Invoice, submit: Option<bool>) -> PushResult {
+        push_invoice(&self.db, self.dir.path(), &self.http, inv.id, submit).await
+    }
+
+    async fn doc(&self, doctype: &str, name: &str) -> Value {
+        let v = self.http.get(&["api", "resource", doctype, name], &[]).await.unwrap_or_else(|e| panic!("read {doctype} {name}: {e}"));
+        v["data"].clone()
+    }
+
+    async fn invoices_named(&self, number: &str) -> Vec<Value> {
+        self.http
+            .list_resource("Sales Invoice", &["name", "docstatus", "grand_total", "remarks"], json!([["remarks", "like", format!("%{number}%")]]), "creation asc")
+            .await
+            .unwrap()
+    }
+
+    async fn files_of(&self, doctype: &str, name: &str) -> Vec<Value> {
+        self.http
+            .list_resource(
+                "File",
+                &["name", "file_name", "is_private", "file_url"],
+                json!([["attached_to_doctype", "=", doctype], ["attached_to_name", "=", name]]),
+                "creation asc",
+            )
+            .await
+            .unwrap()
+    }
+
+    fn payment(&self, inv: &Invoice, cash: i64, tds: i64) -> i64 {
+        let mut conn = self.db.lock().unwrap();
+        record_payment_impl(
+            &mut conn,
+            PaymentInput {
+                invoice_id: inv.id,
+                paid_on: "2026-06-20".into(),
+                amount_paise: cash,
+                tds_paise: tds,
+                mode: "bank_transfer".into(),
+                reference: "UTR-LIVE-1".into(),
+                notes: String::new(),
+            },
+        )
+        .unwrap()
+        .id
+    }
+}
+
+/// A tiny but structurally valid one-page PDF; Frappe parses uploaded PDFs, so a stub header is rejected.
+fn minimal_pdf(label: &str) -> Vec<u8> {
+    let stream = format!("BT /F1 12 Tf 20 100 Td ({label}) Tj ET");
+    let objects = [
+        "<< /Type /Catalog /Pages 2 0 R >>".to_string(),
+        "<< /Type /Pages /Kids [3 0 R] /Count 1 >>".to_string(),
+        "<< /Type /Page /Parent 2 0 R /MediaBox [0 0 200 200] /Contents 4 0 R /Resources << /Font << /F1 5 0 R >> >> >>".to_string(),
+        format!("<< /Length {} >>\nstream\n{stream}\nendstream", stream.len()),
+        "<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>".to_string(),
+    ];
+    let mut out = b"%PDF-1.4\n".to_vec();
+    let mut offsets = Vec::new();
+    for (i, body) in objects.iter().enumerate() {
+        offsets.push(out.len());
+        out.extend(format!("{} 0 obj\n{body}\nendobj\n", i + 1).into_bytes());
+    }
+    let xref = out.len();
+    out.extend(format!("xref\n0 {}\n0000000000 65535 f \n", objects.len() + 1).into_bytes());
+    for o in offsets {
+        out.extend(format!("{o:010} 00000 n \n").into_bytes());
+    }
+    out.extend(format!("trailer\n<< /Size {} /Root 1 0 R >>\nstartxref\n{xref}\n%%EOF\n", objects.len() + 1).into_bytes());
+    out
+}
+
+fn paise(v: &Value) -> i64 {
+    (v.as_f64().unwrap_or_else(|| panic!("not a number: {v}")) * 100.0).round() as i64
+}
+
+fn assert_pushed(r: &PushResult) {
+    assert!(r.ok, "push failed: {:?} {:?}", r.error, r.warnings);
+    assert_eq!(r.status, "synced");
+}
+
+/// The invoice as ERPNext holds it: total equals Voiced's, tax rows are what Voiced computed.
+async fn assert_matches(live: &Live, inv: &Invoice, doc: &Value) {
+    assert_eq!(paise(&doc["grand_total"]), crate::gst::rupees_to_paise(inv.total), "grand_total of {}", inv.number);
+    assert_eq!(doc["rounded_total"].as_f64().unwrap_or(0.0), 0.0, "rounding is disabled");
+    assert_eq!(doc["posting_date"], inv.invoice_date.as_str());
+    let taxes = doc["taxes"].as_array().unwrap();
+    let by_head = |needle: &str| -> Option<i64> {
+        taxes
+            .iter()
+            .find(|t| t["account_head"].as_str().unwrap_or("").contains(needle))
+            .map(|t| paise(&t["tax_amount"]))
+    };
+    assert_eq!(by_head("CGST").unwrap_or(0), crate::gst::rupees_to_paise(inv.cgst_amount).max(0), "CGST of {}", inv.number);
+    // IGST rows contain "IGST"; "CGST" and "SGST" rows do not.
+    assert_eq!(by_head("SGST").unwrap_or(0), crate::gst::rupees_to_paise(inv.sgst_amount), "SGST of {}", inv.number);
+    assert_eq!(by_head("IGST").unwrap_or(0), crate::gst::rupees_to_paise(inv.igst_amount), "IGST of {}", inv.number);
+    let _ = live;
+}
+
+// ---- connection and discovery ----
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_connection_and_options() {
+    let live = Live::new(|_| {}).await;
+    let cfg = live.cfg();
+    let ct = live.connection_test(&cfg).await;
+    println!("{}", serde_json::to_string_pretty(&ct).unwrap());
+    assert!(ct.user.contains('@'));
+    assert_eq!(ct.versions.frappe.as_deref().map(|v| v.starts_with("15.")), Some(true));
+    assert!(ct.versions.erpnext.is_some());
+    assert_eq!(ct.india_compliance, live.ic);
+    assert!(ct.features.v2_naming, "frappe >= 15.73 supports v2 naming");
+
+    let o = live.http.load_options(&cfg.company).await.unwrap();
+    println!("option errors: {:?}", o.errors);
+    assert!(o.errors.is_empty(), "{:?}", o.errors);
+    let has = |list: &[super::discovery::OptionItem], name: &str| list.iter().any(|i| i.name == name);
+    assert!(has(&o.companies, &cfg.company));
+    assert!(has(&o.income_accounts, &cfg.income_account), "{:?}", o.income_accounts);
+    assert!(o.tax_accounts.iter().any(|a| a.name.contains("CGST")), "{:?}", o.tax_accounts);
+    assert!(has(&o.uoms, "Hour") && has(&o.uoms, "Nos"));
+    assert!(!o.company_addresses.is_empty());
+    assert!(!o.naming_series.is_empty());
+    assert!(!o.cost_centers.is_empty() && !o.customer_groups.is_empty() && !o.territories.is_empty());
+}
+
+// ---- Sales Invoice mapping ----
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_push_matrix() {
+    let live = Live::new(|_| {}).await;
+    live.preset("Preset service", "VOICED-SERVICE");
+    let hsn = |i: Value| {
+        let mut i = i;
+        if live.ic {
+            i["hsnSac"] = json!("998314");
+        }
+        i
+    };
+    let cases: Vec<(&str, Invoice)> = vec![
+        (
+            "cgst_sgst",
+            live.issue(true, json!([hsn(json!({"description": "Design", "mode": "fixed", "amount": 7310.0}))]), json!({})),
+        ),
+        (
+            "igst, fractional hours",
+            live.issue(
+                false,
+                json!([hsn(json!({"description": "Consulting", "mode": "rate", "rate": 1234.56, "unit": "hour", "quantity": 2.5}))]),
+                json!({}),
+            ),
+        ),
+        (
+            "discount, repeated description",
+            live.issue(
+                true,
+                json!([
+                    hsn(json!({"description": "Logo", "mode": "fixed", "amount": 3000.0})),
+                    hsn(json!({"description": "Logo", "mode": "fixed", "amount": 2000.5})),
+                ]),
+                json!({"discount": 500.25}),
+            ),
+        ),
+        (
+            "item code via preset",
+            live.issue(
+                true,
+                json!([
+                    hsn(json!({"description": "Preset service", "mode": "fixed", "amount": 1000.0})),
+                    hsn(json!({"description": "Code-less", "mode": "fixed", "amount": 250.0})),
+                ]),
+                json!({"notes": "Thanks\nsecond line"}),
+            ),
+        ),
+    ];
+    for (label, inv) in &cases {
+        live.archive(inv);
+        let r = live.push(inv, None).await;
+        println!("{label}: {} -> {} (warnings {:?})", inv.number, r.remote_name, r.warnings);
+        assert_pushed(&r);
+        assert!(r.created && r.attached, "{label}: {r:?}");
+        assert_eq!(r.remote_name, inv.number, "mirror naming keeps the Voiced number");
+        let doc = live.doc("Sales Invoice", &r.remote_name).await;
+        assert_eq!(doc["docstatus"], 0);
+        assert_matches(&live, inv, &doc).await;
+        let files = live.files_of("Sales Invoice", &r.remote_name).await;
+        assert_eq!(files.len(), 1, "{files:?}");
+        assert_eq!(files[0]["is_private"], 1, "the PDF attachment is private");
+    }
+
+    // Customer and address shape, as ERPNext stored them.
+    let inter = &cases[1].1;
+    let doc = live.doc("Sales Invoice", &inter.number).await;
+    let customer = live.doc("Customer", doc["customer"].as_str().unwrap()).await;
+    assert_eq!(customer["customer_name"], "Voiced Live Inter Co");
+    assert_eq!(customer["customer_type"], "Company");
+    let address = live.doc("Address", doc["customer_address"].as_str().unwrap()).await;
+    println!("address: {}", json!({"state": address["state"], "country": address["country"], "pincode": address["pincode"], "city": address["city"], "type": address["address_type"], "links": address["links"], "gst_category": address["gst_category"], "gstin": address["gstin"]}));
+    assert_eq!(address["state"], "Karnataka");
+    assert_eq!(address["country"], "India");
+    assert_eq!(address["address_type"], "Billing");
+    assert_eq!(address["links"][0]["link_name"], customer["name"]);
+    if live.ic {
+        assert_eq!(customer["gstin"], KA_GSTIN);
+        assert_eq!(customer["gst_category"], "Registered Regular");
+        assert_eq!(address["gstin"], KA_GSTIN);
+        assert_eq!(doc["place_of_supply"], "29-Karnataka");
+    }
+    // A fresh local database (lost link) reuses the customer's address instead of creating another.
+    let again = Live::new(|_| {}).await;
+    let inv = again.issue(false, json!([{"description": "Again", "mode": "fixed", "amount": 100.0, "hsnSac": "998314"}]), json!({}));
+    assert_pushed(&again.push(&inv, None).await);
+    let d2 = again.doc("Sales Invoice", &inv.number).await;
+    assert_eq!(d2["customer_address"], doc["customer_address"], "address reused");
+    assert_eq!(d2["customer"], doc["customer"]);
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_half_paise_rounding() {
+    let live = Live::new(|_| {}).await;
+    let banker = env_or("ERPNEXT_ROUNDING", "banker") == "banker";
+    // (taxable amount, discount): 9% of 10.50 is 0.945, 18% of 0.25 is 0.045 and so on. Voiced rounds half up.
+    // Half-even and half-up agree when the digit before the tie is odd (3.50 -> 0.315 -> 0.32), so only the
+    // first two are certain to differ under Banker's Rounding.
+    let ties = [(10.5, 0.0, true), (7310.5, 0.0, true), (3.5, 0.0, false), (0.25, 0.0, false), (99.99, 0.15, false)];
+    for (amount, discount, tie) in ties {
+        let inv = live.issue(
+            true,
+            json!([{"description": format!("Rounding {amount}"), "mode": "fixed", "amount": amount, "hsnSac": "998314"}]),
+            json!({"discount": discount}),
+        );
+        let r = live.push(&inv, Some(true)).await;
+        println!("{amount}/{discount} tie={tie} banker={banker}: ok={} {:?}", r.ok, r.error);
+        if tie && banker {
+            // ERPNext's Banker's Rounding disagrees by a paise: the draft is reported, kept, and never submitted.
+            assert!(!r.ok && r.status == "conflict" && r.error_kind == Some(ErrorKind::Conflict), "{r:?}");
+            let msg = r.error.as_deref().unwrap();
+            assert!(msg.contains("Commercial Rounding") && msg.contains("does not submit"), "{msg}");
+            assert_eq!(r.remote_name, inv.number);
+            let doc = live.doc("Sales Invoice", &r.remote_name).await;
+            assert_eq!(doc["docstatus"], 0, "a mismatching document is never submitted");
+            assert!(live.files_of("Sales Invoice", &r.remote_name).await.is_empty());
+            // Pushing again finds the same draft and reports the same conflict instead of creating another.
+            let again = live.push(&inv, Some(true)).await;
+            assert!(!again.ok && again.status == "conflict", "{again:?}");
+        } else {
+            assert_pushed(&r);
+            assert_eq!(r.remote_docstatus, 1);
+            let doc = live.doc("Sales Invoice", &r.remote_name).await;
+            assert_matches(&live, &inv, &doc).await;
+        }
+    }
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_repush_is_idempotent() {
+    let live = Live::new(|_| {}).await;
+    let inv = live.issue(true, json!([{"description": "Design", "mode": "fixed", "amount": 500.0, "hsnSac": "998314"}]), json!({}));
+    live.archive(&inv);
+    let first = live.push(&inv, None).await;
+    assert_pushed(&first);
+    assert!(first.created);
+    // Second push with the sync row present: nothing to do.
+    let again = live.push(&inv, None).await;
+    assert_pushed(&again);
+    assert!(again.no_op && !again.created, "{again:?}");
+    // Lose the local sync state: the POST gets a 409 and the document is adopted, not duplicated.
+    live.db.lock().unwrap().execute("DELETE FROM erpnext_sync", []).unwrap();
+    let adopted = live.push(&inv, None).await;
+    assert_pushed(&adopted);
+    assert!(adopted.attached, "{adopted:?}");
+    assert!(!adopted.created, "{adopted:?}");
+    assert_eq!(adopted.remote_name, first.remote_name);
+    let all = live
+        .http
+        .list_resource("Sales Invoice", &["name"], json!([["name", "=", inv.number.clone()]]), "name asc")
+        .await
+        .unwrap();
+    assert_eq!(all.len(), 1);
+    // Losing the sync row also loses the attachment hash; the adopted document must not get a second copy.
+    let files = live.files_of("Sales Invoice", &first.remote_name).await;
+    assert_eq!(files.len(), 1, "{files:?}");
+    assert_eq!(files[0]["is_private"], 1);
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_submit_paths() {
+    let live = Live::new(|_| {}).await;
+    // Submit while creating.
+    let a = live.issue(true, json!([{"description": "A", "mode": "fixed", "amount": 100.0, "hsnSac": "998314"}]), json!({}));
+    let r = live.push(&a, Some(true)).await;
+    assert_pushed(&r);
+    assert_eq!(r.remote_docstatus, 1);
+    assert_eq!(live.doc("Sales Invoice", &r.remote_name).await["docstatus"], 1);
+    // Submit an existing draft in a later push (mirror: v2 method route).
+    let b = live.issue(true, json!([{"description": "B", "mode": "fixed", "amount": 200.0, "hsnSac": "998314"}]), json!({}));
+    assert_pushed(&live.push(&b, Some(false)).await);
+    let r = live.push(&b, Some(true)).await;
+    assert_pushed(&r);
+    assert_eq!(r.remote_docstatus, 1);
+    assert_eq!(live.doc("Sales Invoice", &b.number).await["docstatus"], 1);
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_series_naming_mode() {
+    let live = Live::new(|c| c.naming_mode = NamingMode::Series).await;
+    let o = live.http.load_options(&live.cfg().company).await.unwrap();
+    let series = o.naming_series.first().expect("a naming series").name.clone();
+    println!("series options: {:?}", o.naming_series);
+    live.save_cfg(|c| c.naming_series = series.clone());
+    let inv = live.issue(true, json!([{"description": "Series", "mode": "fixed", "amount": 700.0, "hsnSac": "998314"}]), json!({"notes": "note"}));
+    live.archive(&inv);
+    let r = live.push(&inv, Some(false)).await;
+    assert_pushed(&r);
+    assert!(r.created);
+    assert_ne!(r.remote_name, inv.number, "series mode lets ERPNext name it");
+    let doc = live.doc("Sales Invoice", &r.remote_name).await;
+    assert!(doc["remarks"].as_str().unwrap().starts_with(&format!("Voiced invoice {}", inv.number)), "{}", doc["remarks"]);
+    assert_matches(&live, &inv, &doc).await;
+    // Lose the sync row: the remarks lookup finds the document instead of creating another.
+    live.db.lock().unwrap().execute("DELETE FROM erpnext_sync", []).unwrap();
+    let again = live.push(&inv, Some(false)).await;
+    assert_pushed(&again);
+    assert!(!again.created, "{again:?}");
+    assert_eq!(again.remote_name, r.remote_name);
+    assert_eq!(live.invoices_named(&inv.number).await.len(), 1);
+    // Submit through the v1 run_method route.
+    let s = live.push(&inv, Some(true)).await;
+    assert_pushed(&s);
+    assert_eq!(s.remote_docstatus, 1);
+    assert_eq!(live.doc("Sales Invoice", &r.remote_name).await["docstatus"], 1);
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_uom_and_quantities() {
+    let live = Live::new(|_| {}).await;
+    live.preset("Nos preset", "VOICED-SERVICE"); // stock UOM Nos
+    live.preset("Hourly preset", "VOICED-HOURLY"); // stock UOM Hour
+    let row = |desc: &str, unit: &str, qty: f64| json!([{"description": desc, "mode": "rate", "rate": 100.0, "unit": unit, "quantity": qty, "hsnSac": "998314"}]);
+    let mut outcomes = Vec::new();
+    for (label, desc, unit, qty) in [
+        ("Hour row on a Nos item, whole qty", "Nos preset", "hour", 2.0),
+        ("Hour row on a Nos item, fractional qty", "Nos preset", "hour", 1.5),
+        ("Hour row on an Hour item, fractional qty", "Hourly preset", "hour", 1.5),
+        ("Nos row on an Hour item, whole qty", "Hourly preset", "unit", 3.0),
+        ("code-less hours, fractional qty", "Code-less hours", "hour", 1.5),
+        ("code-less minutes, fractional qty", "Code-less minutes", "minute", 90.5),
+        ("code-less Nos, fractional qty", "Code-less nos", "unit", 1.5),
+        ("code-less Nos, whole qty", "Code-less nos whole", "unit", 4.0),
+    ] {
+        let inv = live.issue(true, row(desc, unit, qty), json!({}));
+        let r = live.push(&inv, None).await;
+        println!("{label}: ok={} {}", r.ok, r.error.clone().unwrap_or_default());
+        outcomes.push((label, r.ok));
+    }
+    println!("{outcomes:?}");
+    let ok = |l: &str| outcomes.iter().find(|(k, _)| *k == l).unwrap().1;
+    assert!(ok("Hour row on an Hour item, fractional qty"));
+    assert!(ok("code-less hours, fractional qty") && ok("code-less minutes, fractional qty"));
+    assert!(ok("code-less Nos, whole qty"));
+    assert!(!ok("code-less Nos, fractional qty"), "ERPNext refuses a fraction of a whole-number UOM");
+}
+
+// ---- payments ----
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_payment_entry() {
+    let live = Live::new(|_| {}).await;
+    let inv = live.issue(true, json!([{"description": "Billable", "mode": "fixed", "amount": 10000.0, "hsnSac": "998314"}]), json!({}));
+    assert_pushed(&live.push(&inv, Some(true)).await);
+    let total = crate::gst::rupees_to_paise(inv.total);
+    // 10% TDS on the taxable value: 1000.00; the cash received is the rest.
+    let tds = 100_000;
+    let cash = total - tds;
+    let pid = live.payment(&inv, cash, tds);
+    let r = push_payment(&live.db, &live.http, pid).await;
+    println!("payment: {r:?}");
+    assert!(r.ok, "{:?}", r.error);
+    let entry = r.entry_name.clone().unwrap();
+    let pe = live.doc("Payment Entry", &entry).await;
+    let keys = ["payment_type", "party_type", "paid_from", "paid_to", "paid_amount", "received_amount", "base_paid_amount", "base_received_amount", "total_allocated_amount", "unallocated_amount", "difference_amount", "reference_no", "reference_date", "posting_date", "bank_account", "mode_of_payment", "status"];
+    println!("PE {}", json!(keys.iter().map(|k| (k.to_string(), pe[*k].clone())).collect::<serde_json::Map<_, _>>()));
+    println!("PE references {}", pe["references"].as_array().unwrap().iter().map(|r| json!({"ref": r["reference_name"], "allocated": r["allocated_amount"], "total": r["total_amount"], "outstanding": r["outstanding_amount"]}).to_string()).collect::<Vec<_>>().join(","));
+    println!("PE deductions {}", pe["deductions"].as_array().unwrap().iter().map(|r| json!({"account": r["account"], "cost_center": r["cost_center"], "amount": r["amount"], "description": r["description"]}).to_string()).collect::<Vec<_>>().join(","));
+    assert_eq!(paise(&pe["paid_amount"]), cash);
+    assert_eq!(paise(&pe["received_amount"]), cash);
+    assert_eq!(paise(&pe["total_allocated_amount"]), cash + tds);
+    assert_eq!(paise(&pe["difference_amount"]), 0);
+    let ded = pe["deductions"].as_array().unwrap();
+    assert_eq!(ded.len(), 1);
+    assert_eq!(ded[0]["account"], live.cfg().tds_account.as_str());
+    assert_eq!(paise(&ded[0]["amount"]), tds, "a TDS deduction row is a positive amount");
+    assert_eq!(pe["reference_no"], "UTR-LIVE-1");
+    assert_eq!(pe["posting_date"], "2026-06-20");
+    assert_eq!(pe["paid_to"], live.cfg().payment_bank_account.as_str(), "money lands in the configured bank account");
+    let inv_doc = live.doc("Sales Invoice", &inv.number).await;
+    println!("outstanding after payment: {}", inv_doc["outstanding_amount"]);
+    assert_eq!(pe["docstatus"], 1);
+    assert_eq!(paise(&inv_doc["outstanding_amount"]), 0, "cash plus TDS settles the invoice");
+    // Idempotent locally.
+    let again = push_payment(&live.db, &live.http, pid).await;
+    assert!(again.ok && again.already_synced);
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_payment_without_tds() {
+    let live = Live::new(|_| {}).await;
+    let inv = live.issue(true, json!([{"description": "Plain", "mode": "fixed", "amount": 1000.0, "hsnSac": "998314"}]), json!({}));
+    assert_pushed(&live.push(&inv, Some(true)).await);
+    let total = crate::gst::rupees_to_paise(inv.total);
+    let pid = live.payment(&inv, total / 2, 0);
+    let r = push_payment(&live.db, &live.http, pid).await;
+    assert!(r.ok, "{:?}", r.error);
+    let inv_doc = live.doc("Sales Invoice", &inv.number).await;
+    assert_eq!(paise(&inv_doc["outstanding_amount"]), total - total / 2, "partial payment leaves the rest outstanding");
+}
+
+// ---- India Compliance only (ERPNEXT_IC=1) ----
+
+fn skip_without_ic() -> bool {
+    if env_or("ERPNEXT_IC", "0") != "1" {
+        eprintln!("skipped: the site has no India Compliance (ERPNEXT_IC is not 1)");
+        return true;
+    }
+    false
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack with India Compliance"]
+async fn live_ic_hsn_enforcement() {
+    if skip_without_ic() {
+        return;
+    }
+    let live = Live::new(|_| {}).await;
+    let mut outcomes = Vec::new();
+    for (label, hsn) in [("no HSN", ""), ("4-digit HSN", "9983"), ("6-digit HSN", "998314"), ("8-digit HSN", "99831400")] {
+        let inv = live.issue(true, json!([{"description": format!("HSN {label}"), "mode": "fixed", "amount": 1000.0, "hsnSac": hsn}]), json!({}));
+        let r = live.push(&inv, Some(true)).await;
+        println!("{label}: ok={} docstatus={} err={:?}", r.ok, r.remote_docstatus, r.error);
+        outcomes.push((label, r));
+    }
+    let get = |l: &str| &outcomes.iter().find(|(k, _)| *k == l).unwrap().1;
+    assert!(get("6-digit HSN").ok && get("6-digit HSN").remote_docstatus == 1);
+    assert!(get("8-digit HSN").ok && get("8-digit HSN").remote_docstatus == 1);
+    for bad in ["no HSN", "4-digit HSN"] {
+        let r = get(bad);
+        assert!(!r.ok, "{bad} must be refused: {r:?}");
+        let msg = r.error.as_deref().unwrap();
+        assert!(msg.to_ascii_uppercase().contains("HSN"), "{bad}: {msg}");
+    }
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack with India Compliance"]
+async fn live_ic_number_longer_than_16_characters() {
+    if skip_without_ic() {
+        return;
+    }
+    let live = Live::new(|_| {}).await;
+    let inv = live.issue(true, json!([{"description": "Long number", "mode": "fixed", "amount": 1000.0, "hsnSac": "998314"}]), json!({}));
+    // Voiced never issues such a number; this is a number imported or migrated from elsewhere.
+    let long = format!("{}-EXTRA-LONG-PART", inv.number);
+    assert!(long.len() > 16);
+    live.db.lock().unwrap().execute("UPDATE invoices SET number = ?1 WHERE id = ?2", params![long, inv.id]).unwrap();
+    let r = live.push(&inv, None).await;
+    println!("long number: ok={} err={:?}", r.ok, r.error);
+    assert!(!r.ok);
+    let msg = r.error.as_deref().unwrap();
+    assert!(msg.contains("16"), "{msg}");
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack with India Compliance"]
+async fn live_ic_gst_account_warnings() {
+    if skip_without_ic() {
+        return;
+    }
+    let live = Live::new(|_| {}).await;
+    let local = LocalFacts { vendor_registered: true, ..Default::default() };
+    let codes = |ct: &ConnectionTest| ct.warnings.iter().map(|w| w.code.clone()).collect::<Vec<_>>();
+
+    let clean = test_connection(&live.http, &live.cfg(), &local).await.unwrap();
+    assert!(clean.warnings.is_empty(), "{:?}", clean.warnings);
+
+    let mut cfg = live.cfg();
+    cfg.cgst_account = format!("Input Tax CGST - {}", live.abbr);
+    let wrong = test_connection(&live.http, &cfg, &local).await.unwrap();
+    assert_eq!(codes(&wrong), ["gst_account_mismatch"], "{:?}", wrong.warnings);
+
+    let mut cfg = live.cfg();
+    cfg.company = "No Such Co".into();
+    let other = test_connection(&live.http, &cfg, &local).await.unwrap();
+    assert!(codes(&other).contains(&"gst_accounts_not_configured".to_string()), "{:?}", other.warnings);
+
+    // Mirror mode with a number the site would refuse.
+    let local = LocalFacts { vendor_registered: true, next_number: Some("TOOLONG-INVOICE-0001".into()), ..Default::default() };
+    let ct = test_connection(&live.http, &live.cfg(), &local).await.unwrap();
+    assert!(codes(&ct).contains(&"number_invalid".to_string()), "{:?}", ct.warnings);
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack with India Compliance"]
+async fn live_ic_reverse_charge_and_gst_fields() {
+    if skip_without_ic() {
+        return;
+    }
+    let live = Live::new(|_| {}).await;
+    let inv = live.issue(false, json!([{"description": "RCM service", "mode": "fixed", "amount": 1000.0, "hsnSac": "998314"}]), json!({"reverseCharge": true}));
+    let r = live.push(&inv, None).await;
+    // India Compliance refuses is_reverse_charge=1 without negative RCM tax rows ("Booked reverse charge is not
+    // equal to applied tax amount"), whatever GST Settings say, so it is sent as 0 with a warning.
+    assert_pushed(&r);
+    assert!(r.warnings.iter().any(|w| w.contains("reverse charge")), "{:?}", r.warnings);
+    let doc = live.doc("Sales Invoice", &r.remote_name).await;
+    assert_eq!(doc["is_reverse_charge"], 0);
+    assert_matches(&live, &inv, &doc).await;
+    assert_eq!(doc["place_of_supply"], "29-Karnataka");
+    assert_eq!(doc["company_gstin"], VENDOR_GSTIN);
+    assert_eq!(doc["gst_category"], "Registered Regular");
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack with India Compliance"]
+async fn live_ic_state_names_match_voiced() {
+    if skip_without_ic() {
+        return;
+    }
+    let live = Live::new(|_| {}).await;
+    let v = live.http.get(&["api", "method", "frappe.desk.form.load.getdoctype"], &[("doctype", "Address".to_string())]).await.unwrap();
+    let docs = v["docs"].as_array().unwrap();
+    let address = docs.iter().find(|d| d["name"] == "Address").unwrap();
+    let options = address["fields"].as_array().unwrap().iter().find(|f| f["fieldname"] == "gst_state").expect("IC adds gst_state");
+    let ic: Vec<&str> = options["options"].as_str().unwrap().lines().map(str::trim).filter(|l| !l.is_empty()).collect();
+    for (code, name) in crate::gst::STATES {
+        assert!(ic.contains(name), "India Compliance has no state named {name:?} ({code}); it has {ic:?}");
+    }
+    assert_eq!(ic.len(), crate::gst::STATES.len(), "{ic:?}");
+}
+
+#[tokio::test]
+#[ignore = "needs the live ERPNext stack"]
+async fn live_payment_edge_cases() {
+    let live = Live::new(|_| {}).await;
+    let inv = live.issue(true, json!([{"description": "Edge", "mode": "fixed", "amount": 1000.0, "hsnSac": "998314"}]), json!({}));
+    // Not submitted yet: refused locally, nothing sent.
+    assert_pushed(&live.push(&inv, Some(false)).await);
+    let early = live.payment(&inv, 100_00, 0);
+    let r = push_payment(&live.db, &live.http, early).await;
+    assert!(!r.ok && r.error.as_deref().unwrap().contains("not submitted"), "{r:?}");
+    assert_pushed(&live.push(&inv, Some(true)).await);
+    let total = crate::gst::rupees_to_paise(inv.total);
+    // TDS only (no cash): settled by deduction alone.
+    let tds_only = live.payment(&inv, 0, total - 100_00);
+    let r = push_payment(&live.db, &live.http, tds_only).await;
+    assert!(!r.ok && r.error.as_deref().unwrap().contains("TDS only"), "{r:?}");
+    // Without a configured TDS account a TDS payment is refused locally.
+    live.save_cfg(|c| c.tds_account = String::new());
+    let inv2 = live.issue(true, json!([{"description": "Edge 2", "mode": "fixed", "amount": 1000.0, "hsnSac": "998314"}]), json!({}));
+    assert_pushed(&live.push(&inv2, Some(true)).await);
+    let t = live.payment(&inv2, 100_00, 50_00);
+    let r = push_payment(&live.db, &live.http, t).await;
+    assert!(!r.ok && r.error.as_deref().unwrap().contains("TDS account"), "{r:?}");
+}

src-tauri/src/integrations/erpnext/mod.rs

@@ -0,0 +1,18 @@
+//! ERPNext / Frappe integration. All HTTP runs in Rust (see `client`); `mapping` is pure and
+//! snapshot-tested; `config` owns the stored settings and the API secret.
+
+// Parts of this module are only used by the later UI step.
+#![allow(dead_code)]
+
+pub mod client;
+pub mod config;
+pub mod discovery;
+pub mod errors;
+pub mod mapping;
+pub mod push;
+
+#[cfg(test)]
+pub(crate) mod testutil;
+
+#[cfg(test)]
+mod live_tests;

src-tauri/src/integrations/erpnext/testutil.rs

@@ -0,0 +1,117 @@
+//! A tiny HTTP/1.1 mock server for client tests (one request per connection, scripted or routed replies).
+
+use super::client::{ClientOptions, ErpClient};
+use super::config::Secret;
+use serde_json::Value;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpListener;
+
+pub struct Reply {
+    pub status: u16,
+    pub headers: Vec<(&'static str, String)>,
+    pub body: String,
+    /// Pause before answering, to trigger the read timeout.
+    pub delay_ms: u64,
+}
+
+pub fn reply(status: u16, body: Value) -> Reply {
+    Reply { status, headers: vec![], body: body.to_string(), delay_ms: 0 }
+}
+
+pub struct Mock {
+    pub base: String,
+    pub hits: Arc<AtomicUsize>,
+    /// Raw requests (head and body) in arrival order.
+    pub requests: Arc<Mutex<Vec<String>>>,
+}
+
+/// Serves the scripted replies in order; the last one repeats.
+pub async fn serve(script: Vec<Reply>) -> Mock {
+    let script = Arc::new(script);
+    serve_fn(move |i, _| {
+        let r = &script[i.min(script.len() - 1)];
+        Reply { status: r.status, headers: r.headers.clone(), body: r.body.clone(), delay_ms: r.delay_ms }
+    })
+    .await
+}
+
+/// Answers every request with `handler(request_index, request_line)`.
+pub async fn serve_fn(handler: impl Fn(usize, &str) -> Reply + Send + Sync + 'static) -> Mock {
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let port = listener.local_addr().unwrap().port();
+    let hits = Arc::new(AtomicUsize::new(0));
+    let requests = Arc::new(Mutex::new(Vec::new()));
+    let (h, r) = (hits.clone(), requests.clone());
+    let handler = Arc::new(handler);
+    tokio::spawn(async move {
+        loop {
+            let Ok((mut sock, _)) = listener.accept().await else { return };
+            let (h, r, handler) = (h.clone(), r.clone(), handler.clone());
+            tokio::spawn(async move {
+                let mut buf = Vec::new();
+                let mut chunk = [0u8; 2048];
+                loop {
+                    let n = sock.read(&mut chunk).await.unwrap_or(0);
+                    if n == 0 {
+                        break;
+                    }
+                    buf.extend_from_slice(&chunk[..n]);
+                    if let Some(end) = buf.windows(4).position(|w| w == b"\r\n\r\n") {
+                        let head = String::from_utf8_lossy(&buf[..end]).to_string();
+                        let want = head
+                            .lines()
+                            .find_map(|l| {
+                                l.to_ascii_lowercase()
+                                    .strip_prefix("content-length:")
+                                    .map(|v| v.trim().parse::<usize>().unwrap_or(0))
+                            })
+                            .unwrap_or(0);
+                        if buf.len() >= end + 4 + want {
+                            break;
+                        }
+                    }
+                }
+                let raw = String::from_utf8_lossy(&buf).to_string();
+                let request_line = raw.lines().next().unwrap_or("").to_string();
+                r.lock().unwrap().push(raw);
+                let i = h.fetch_add(1, Ordering::SeqCst);
+                let rep = handler(i, &request_line);
+                if rep.delay_ms > 0 {
+                    tokio::time::sleep(Duration::from_millis(rep.delay_ms)).await;
+                }
+                let mut out = format!(
+                    "HTTP/1.1 {} X\r\nContent-Type: application/json\r\nContent-Length: {}\r\nConnection: close\r\n",
+                    rep.status,
+                    rep.body.len()
+                );
+                for (k, v) in &rep.headers {
+                    out.push_str(&format!("{k}: {v}\r\n"));
+                }
+                out.push_str("\r\n");
+                out.push_str(&rep.body);
+                let _ = sock.write_all(out.as_bytes()).await;
+                let _ = sock.shutdown().await;
+            });
+        }
+    });
+    Mock { base: format!("http://127.0.0.1:{port}"), hits, requests }
+}
+
+/// Short timeouts and near-zero backoff so retry tests run in milliseconds.
+pub fn fast_opts() -> ClientOptions {
+    ClientOptions {
+        connect_timeout: Duration::from_secs(2),
+        read_timeout: Duration::from_millis(250),
+        total_timeout: Duration::from_secs(5),
+        max_retries: 3,
+        backoff_base: Duration::from_millis(1),
+        max_backoff: Duration::from_millis(5),
+    }
+}
+
+pub fn client(mock: &Mock) -> ErpClient {
+    ErpClient::new(&mock.base, "thekey", &Secret::new("thesecret"), "", fast_opts()).unwrap()
+}

src-tauri/src/integrations/mod.rs

@@ -0,0 +1,89 @@
+//! Outbound integrations. `InvoiceSink` is the seam between Voiced and a system that receives issued
+//! invoices (ERPNext now; a webhook, Zoho or a Tally import later). Everything target-specific lives in a
+//! submodule; the rest of the app only talks to this trait.
+
+// Parts of the sink API are only used by the later UI step.
+#![allow(dead_code)]
+
+pub mod erpnext;
+
+use serde::Serialize;
+use std::future::Future;
+
+/// What a sink reports after accepting an invoice.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct PushedInvoice {
+    /// The document name on the remote system.
+    pub remote_name: String,
+    /// 0 draft, 1 submitted.
+    pub remote_docstatus: i64,
+    /// False when the remote already had this invoice (an idempotent re-push).
+    pub created: bool,
+    /// Non-fatal notes, e.g. "pushed without the PDF because the invoice is not archived".
+    pub warnings: Vec<String>,
+}
+
+pub struct PushRequest {
+    pub invoice_id: i64,
+    /// Submit on the remote system instead of leaving a draft for review; `None` follows the sink's setting.
+    pub submit: Option<bool>,
+}
+
+pub struct PaymentRequest {
+    pub payment_id: i64,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct PushedPayment {
+    pub remote_name: String,
+    /// False when the payment had already been sent (an idempotent re-push).
+    pub created: bool,
+}
+
+/// The locally recorded sync state of one invoice. `status` is `none` until something was pushed, then
+/// `synced`, `error` or `conflict`.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SyncStatus {
+    pub invoice_id: i64,
+    pub status: String,
+    pub remote_name: String,
+    /// 0 draft, 1 submitted.
+    pub remote_docstatus: i64,
+    pub last_error: String,
+    pub synced_at: Option<String>,
+    /// The archived PDF was uploaded to the remote document.
+    pub attached: bool,
+}
+
+impl SyncStatus {
+    pub fn none(invoice_id: i64) -> Self {
+        SyncStatus {
+            invoice_id,
+            status: "none".into(),
+            remote_name: String::new(),
+            remote_docstatus: 0,
+            last_error: String::new(),
+            synced_at: None,
+            attached: false,
+        }
+    }
+}
+
+pub trait InvoiceSink: Send + Sync {
+    /// Stable identifier used in the sync table (`erpnext`, ...).
+    fn id(&self) -> &'static str;
+
+    fn push_invoice<'a>(
+        &'a self,
+        request: PushRequest,
+    ) -> impl Future<Output = Result<PushedInvoice, String>> + Send + 'a;
+
+    fn push_payment<'a>(
+        &'a self,
+        request: PaymentRequest,
+    ) -> impl Future<Output = Result<PushedPayment, String>> + Send + 'a;
+
+    /// The locally recorded state; never touches the network.
+    fn status(&self, invoice_id: i64) -> Result<SyncStatus, String>;
+}

src-tauri/src/lib.rs

@@ -1,6 +1,7 @@
 mod commands;
 mod db;
 mod gst;
+mod integrations;
 mod logo;
 mod models;
 mod selftest;
@@ -176,6 +177,16 @@ pub fn run() {
             commands::files::get_last_export_dir,
             commands::files::reveal_in_folder,
             commands::files::open_file,
+            commands::erpnext::erpnext_get_config,
+            commands::erpnext::erpnext_save_config,
+            commands::erpnext::erpnext_test_connection,
+            commands::erpnext::erpnext_load_options,
+            commands::erpnext::erpnext_push_invoice,
+            commands::erpnext::erpnext_push_invoices,
+            commands::erpnext::erpnext_push_payment,
+            commands::erpnext::erpnext_sync_status,
+            commands::erpnext::erpnext_sync_statuses,
+            commands::erpnext::erpnext_open_url,
             selftest::selftest_config,
             selftest::selftest_report,
         ])

src/App.tsx

@@ -10,6 +10,7 @@ import InvoiceDetail from "./views/InvoiceDetail";
 import Clients from "./views/Clients";
 import { ToastProvider, useToast } from "./components/ToastProvider";
 import AppSettings from "./views/AppSettings";
+import { requestSettingsTab } from "./lib/settingsTab";
 
 export default function App() {
   return (
@@ -89,6 +90,11 @@ function AppInner() {
     );
   }
 
+  const openIntegrations = () => {
+    requestSettingsTab("integrations");
+    setView("settings");
+  };
+
   const toggleTheme = async () => {
     const next: Settings = { ...settings, theme: settings.theme === "g100" ? "g10" : "g100" };
     setSettings(next);
@@ -115,6 +121,7 @@ function AppInner() {
           <InvoiceHistory
             settings={settings}
             active={view === "invoices"}
+            onOpenSettings={openIntegrations}
             onOpen={(id) => {
               setDetailId(id);
               setView("invoice");
@@ -127,6 +134,7 @@ function AppInner() {
             invoiceId={detailId}
             settings={settings}
             onBack={() => setView("invoices")}
+            onOpenSettings={openIntegrations}
             onDuplicated={(draftId) => {
               setOpenDraftId(draftId);
               setView("new");

src/components/ErpnextSettingsPanel.tsx

@@ -0,0 +1,591 @@
+import { useCallback, useEffect, useMemo, useState } from "react";
+import {
+  Button,
+  ComboBox,
+  FileUploaderButton,
+  InlineLoading,
+  InlineNotification,
+  PasswordInput,
+  RadioButton,
+  RadioButtonGroup,
+  TextArea,
+  TextInput,
+  Tag,
+  Tile,
+  Toggle,
+} from "@carbon/react";
+import { Save } from "@carbon/icons-react";
+import { api } from "../lib/api";
+import type { ErpnextConfig, ErpnextConfigInput, ErpnextConnectionTest, ErpnextOptionItem, ErpnextOptions } from "../lib/erpnext";
+import {
+  OPTION_LIST_LABELS,
+  UOM_UNITS,
+  connectionProblems,
+  emptyOptions,
+  hasProblems,
+  mirrorSupported,
+  optionErrors,
+  optionText,
+  sortWarnings,
+  toInput,
+  validateConfigForm,
+  versionsLine,
+  warningSeverity,
+  withStoredValue,
+  type FormProblems,
+} from "../lib/erpnextUi";
+import { useToast } from "./ToastProvider";
+
+const SEVERITY_TITLE = { error: "Needs fixing", warning: "Warning", info: "Note" } as const;
+
+interface PickProps {
+  id: string;
+  label: string;
+  value: string;
+  onChange: (value: string) => void;
+  /** The loaded list; an empty list means "not loaded", and the field takes typed text instead. */
+  items: ErpnextOptionItem[];
+  /** Why this list is empty although the lists were loaded (a load error for this list). */
+  error?: string;
+  /** The control is switched off, with the reason shown under it. */
+  disabledReason?: string;
+  helper?: string;
+}
+
+/** A searchable dropdown over a live list, or a text box while the list has not been loaded. */
+function PickField({ id, label, value, onChange, items, error, disabledReason, helper }: PickProps) {
+  const options = useMemo(() => withStoredValue(items, value), [items, value]);
+  const note = disabledReason ?? error ?? helper;
+  if (items.length === 0 || disabledReason) {
+    return (
+      <TextInput
+        id={id}
+        labelText={label}
+        value={value}
+        disabled={Boolean(disabledReason)}
+        invalid={Boolean(error) && !disabledReason}
+        invalidText={error}
+        helperText={error ? undefined : note}
+        onChange={(e) => onChange(e.target.value)}
+      />
+    );
+  }
+  return (
+    <ComboBox
+      id={id}
+      titleText={label}
+      items={options}
+      itemToString={(i: ErpnextOptionItem | null) => (i ? optionText(i) : "")}
+      selectedItem={options.find((o) => o.name === value) ?? null}
+      onChange={({ selectedItem }: { selectedItem?: ErpnextOptionItem | null }) => onChange(selectedItem?.name ?? "")}
+      shouldFilterItem={({ item, inputValue }: { item: ErpnextOptionItem; inputValue: string | null }) =>
+        !inputValue || optionText(item).toLowerCase().includes(inputValue.toLowerCase())
+      }
+      helperText={helper}
+      placeholder="Search or choose"
+    />
+  );
+}
+
+function Section({ title, children, note }: { title: string; children: React.ReactNode; note?: string }) {
+  return (
+    <section className="voiced-erp__section" aria-label={title}>
+      <h3>{title}</h3>
+      {note ? <p className="voiced-muted">{note}</p> : null}
+      <div className="voiced-erp__fields">{children}</div>
+    </section>
+  );
+}
+
+/** Settings, Integrations, ERPNext. It has its own Save: the page-level Save settings button does not cover it. */
+export default function ErpnextSettingsPanel({ active }: { active: boolean }) {
+  const toast = useToast();
+  const [saved, setSaved] = useState<ErpnextConfig | null>(null);
+  const [form, setForm] = useState<ErpnextConfigInput | null>(null);
+  const [loadError, setLoadError] = useState<string | null>(null);
+  const [replacing, setReplacing] = useState(false);
+  const [test, setTest] = useState<ErpnextConnectionTest | null>(null);
+  /** A test result from this session that is not saved yet. */
+  const [testUnsaved, setTestUnsaved] = useState(false);
+  const [testError, setTestError] = useState<string | null>(null);
+  const [testing, setTesting] = useState(false);
+  const [options, setOptions] = useState<ErpnextOptions | null>(null);
+  const [loadingOptions, setLoadingOptions] = useState(false);
+  const [saving, setSaving] = useState(false);
+  const [showProblems, setShowProblems] = useState(false);
+  const [saveError, setSaveError] = useState<string | null>(null);
+
+  const load = useCallback(async () => {
+    try {
+      const cfg = await api.erpnextGetConfig();
+      setSaved(cfg);
+      setForm(toInput(cfg));
+      setTest(cfg.lastDetectResult);
+      setTestUnsaved(false);
+      setLoadError(null);
+    } catch (e) {
+      setLoadError(String(e));
+    }
+  }, []);
+
+  useEffect(() => {
+    if (active && form === null) void load();
+    // Reload only on first show; edits must survive switching tabs.
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [active]);
+
+  if (loadError) {
+    return <InlineNotification kind="error" lowContrast hideCloseButton title="Could not load the ERPNext settings" subtitle={loadError} />;
+  }
+  if (!form || !saved) return <InlineLoading description="Loading ERPNext settings" />;
+
+  const set = <K extends keyof ErpnextConfigInput>(key: K, value: ErpnextConfigInput[K]) => setForm((f) => (f ? { ...f, [key]: value } : f));
+  const secretStored = saved.apiSecretSet;
+  const secretShown = secretStored && !replacing && !form.clearSecret;
+  const problems: FormProblems = showProblems ? validateConfigForm(form, secretStored, test) : {};
+  const connProblems = connectionProblems(form, secretStored);
+  const canConnect = !hasProblems(connProblems);
+  const optErrors = optionErrors(options);
+  const opts = options ?? emptyOptions();
+  const noCompany = !form.company.trim();
+  const companyReason = noCompany ? "Pick a company first." : undefined;
+  const seriesMode = form.namingMode === "series";
+  const mirrorOk = mirrorSupported(test);
+
+  const loadOptions = async (values: ErpnextConfigInput) => {
+    setLoadingOptions(true);
+    try {
+      setOptions(await api.erpnextLoadOptions(values));
+    } catch (e) {
+      setOptions(null);
+      toast.error("Could not load the ERPNext lists", String(e));
+    } finally {
+      setLoadingOptions(false);
+    }
+  };
+
+  const runTest = async () => {
+    setShowProblems(true);
+    if (!canConnect) return;
+    setTesting(true);
+    setTestError(null);
+    try {
+      const result = await api.erpnextTestConnection(form);
+      setTest(result);
+      setTestUnsaved(true);
+      let next = form;
+      // A site that keeps no posted name cannot mirror the Voiced number.
+      if (!result.features.v2Naming && form.namingMode === "mirror") {
+        next = { ...form, namingMode: "series" };
+        setForm(next);
+      }
+      await loadOptions(next);
+    } catch (e) {
+      setTestError(String(e));
+    } finally {
+      setTesting(false);
+    }
+  };
+
+  const changeCompany = (company: string) => {
+    const next = { ...form, company };
+    setForm(next);
+    // Accounts, addresses and cost centers belong to the company, so the lists are reloaded for it.
+    if (options && canConnect) void loadOptions(next);
+  };
+
+  const save = async () => {
+    setShowProblems(true);
+    setSaveError(null);
+    if (hasProblems(validateConfigForm(form, secretStored, test))) return;
+    setSaving(true);
+    try {
+      const cfg = await api.erpnextSaveConfig({ ...form, ...(testUnsaved && test ? { lastDetectResult: test } : {}) });
+      setSaved(cfg);
+      setForm(toInput(cfg));
+      setReplacing(false);
+      setTest(cfg.lastDetectResult ?? test);
+      setTestUnsaved(false);
+      setShowProblems(false);
+      toast.success("ERPNext settings saved");
+    } catch (e) {
+      const text = String(e);
+      setSaveError(text);
+      toast.error("Could not save the ERPNext settings", text);
+    } finally {
+      setSaving(false);
+    }
+  };
+
+  const readPem = async (file: File | undefined) => {
+    if (!file) return;
+    try {
+      set("extraCaPem", (await file.text()).trim());
+    } catch (e) {
+      toast.error("Could not read the certificate file", String(e));
+    }
+  };
+
+  const secretInvalid = problems.apiSecret ?? (saveError && /secret again/i.test(saveError) ? saveError : undefined);
+
+  return (
+    <div className="voiced-stack voiced-erp">
+      <div>
+        <h2 className="voiced-detail__h2">ERPNext</h2>
+        <p>
+          Send issued invoices and payments to your ERPNext site as Sales Invoices. Everything is sent from this computer; ERPNext is never
+          needed to issue an invoice.
+        </p>
+        <p className="voiced-muted">
+          Create a dedicated ERPNext user for Voiced with only these permissions: create and submit Sales Invoice, read on the master data
+          (Customer, Item, Address, Account, Company), and write on File. Use that user&rsquo;s API key and secret below. An address must be
+          https://; plain http is only allowed for localhost, 127.0.0.1, *.localhost and *.test hosts.
+        </p>
+      </div>
+
+      <Section title="Connection">
+        <TextInput
+          id="erp-baseUrl"
+          labelText="Site address"
+          placeholder="https://erp.example.com"
+          value={form.baseUrl}
+          invalid={Boolean(problems.baseUrl)}
+          invalidText={problems.baseUrl}
+          onChange={(e) => set("baseUrl", e.target.value)}
+        />
+        <TextInput
+          id="erp-apiKey"
+          labelText="API key"
+          autoComplete="off"
+          value={form.apiKey}
+          invalid={Boolean(problems.apiKey)}
+          invalidText={problems.apiKey}
+          onChange={(e) => set("apiKey", e.target.value)}
+        />
+        {secretShown ? (
+          <div className="voiced-erp__secret">
+            <p className="voiced-erp__label" id="erp-secret-label">
+              API secret
+            </p>
+            <p aria-labelledby="erp-secret-label">
+              <Tag type="green" size="sm">
+                set
+              </Tag>{" "}
+              <span className="voiced-muted">The secret is stored on this computer and is never shown again.</span>
+            </p>
+            <div className="voiced-header-action">
+              <Button kind="tertiary" size="sm" onClick={() => setReplacing(true)}>
+                Replace
+              </Button>
+              <Button kind="ghost" size="sm" onClick={() => set("clearSecret", true)}>
+                Clear
+              </Button>
+            </div>
+          </div>
+        ) : (
+          <div>
+            <PasswordInput
+              id="erp-apiSecret"
+              labelText="API secret"
+              autoComplete="new-password"
+              value={form.apiSecret}
+              invalid={Boolean(secretInvalid)}
+              invalidText={secretInvalid}
+              helperText={form.clearSecret ? "The stored secret is removed when you save, unless you type a new one." : undefined}
+              onChange={(e) => set("apiSecret", e.target.value)}
+            />
+            {secretStored ? (
+              <Button
+                kind="ghost"
+                size="sm"
+                onClick={() => {
+                  setReplacing(false);
+                  setForm((f) => (f ? { ...f, apiSecret: "", clearSecret: false } : f));
+                }}
+              >
+                Keep the stored secret
+              </Button>
+            ) : null}
+          </div>
+        )}
+        <div>
+          <TextArea
+            id="erp-extraCa"
+            labelText="Extra CA certificate (optional, PEM)"
+            helperText="Only for a self-hosted site whose certificate is not trusted by this computer."
+            rows={3}
+            value={form.extraCaPem}
+            onChange={(e) => set("extraCaPem", e.target.value)}
+          />
+          <FileUploaderButton
+            labelText="Load from file…"
+            buttonKind="ghost"
+            size="sm"
+            accept={[".pem", ".crt", ".cer"]}
+            disableLabelChanges
+            onChange={(e: React.ChangeEvent<HTMLInputElement>) => {
+              const file = e.target.files?.[0];
+              e.target.value = "";
+              void readPem(file);
+            }}
+          />
+        </div>
+        <div className="voiced-header-action">
+          <Button kind="secondary" size="md" onClick={() => void runTest()} disabled={testing || loadingOptions}>
+            {testing ? "Testing…" : "Test connection"}
+          </Button>
+          {testing || loadingOptions ? <InlineLoading description={testing ? "Contacting ERPNext" : "Loading lists"} /> : null}
+          {!canConnect && showProblems ? <span className="voiced-muted">Fix the address, key and secret first.</span> : null}
+        </div>
+        {testError ? <InlineNotification kind="error" lowContrast hideCloseButton title="Connection failed" subtitle={testError} /> : null}
+        {test ? (
+          <Tile className="voiced-erp__result" aria-label="Connection test result">
+            <p>
+              <strong>Connected as {test.user || "an unknown user"}</strong>{" "}
+              <Tag type={test.indiaCompliance ? "green" : "warm-gray"} size="sm">
+                {test.indiaCompliance ? "India Compliance detected" : "India Compliance not detected"}
+              </Tag>
+            </p>
+            <p className="voiced-muted">{versionsLine(test)}</p>
+            {testUnsaved ? (
+              <InlineNotification
+                kind="info"
+                lowContrast
+                hideCloseButton
+                title="Save to keep this result"
+                subtitle="Sending invoices needs a saved connection test."
+              />
+            ) : (
+              <p className="voiced-muted">Last saved test result.</p>
+            )}
+            {sortWarnings(test.warnings).map((w, i) => {
+              const severity = warningSeverity(w.code);
+              return (
+                <InlineNotification
+                  key={`${w.code}-${i}`}
+                  kind={severity}
+                  lowContrast
+                  hideCloseButton
+                  title={SEVERITY_TITLE[severity]}
+                  subtitle={w.message}
+                />
+              );
+            })}
+            {test.warnings.length === 0 ? <p className="voiced-muted">No problems found with the current settings.</p> : null}
+            <p className="voiced-muted">Test again after changing the mappings below to refresh these warnings.</p>
+          </Tile>
+        ) : null}
+      </Section>
+
+      <Section
+        title="Company and accounts"
+        note={options ? "Choose from what your ERPNext site has." : "Run Test connection to choose from your site's lists; until then, type the exact names."}
+      >
+        {options && options.errors.length > 0 ? (
+          <InlineNotification
+            kind="warning"
+            lowContrast
+            hideCloseButton
+            title="Some lists could not be loaded"
+            subtitle={options.errors.map((e) => `${OPTION_LIST_LABELS[e.list] ?? e.list}: ${e.message}`).join(" ")}
+          />
+        ) : null}
+        <PickField
+          id="erp-company"
+          label="Company"
+          value={form.company}
+          onChange={changeCompany}
+          items={opts.companies}
+          error={optErrors.get("companies")}
+        />
+        <PickField
+          id="erp-companyAddress"
+          label="Company address"
+          value={form.companyAddress}
+          onChange={(v) => set("companyAddress", v)}
+          items={opts.companyAddresses}
+          error={optErrors.get("companyAddresses")}
+          disabledReason={companyReason}
+          helper="Required by India Compliance on every invoice."
+        />
+        <PickField
+          id="erp-incomeAccount"
+          label="Income account"
+          value={form.incomeAccount}
+          onChange={(v) => set("incomeAccount", v)}
+          items={opts.incomeAccounts}
+          error={optErrors.get("incomeAccounts")}
+          disabledReason={companyReason}
+        />
+        <PickField
+          id="erp-costCenter"
+          label="Cost center"
+          value={form.costCenter}
+          onChange={(v) => set("costCenter", v)}
+          items={opts.costCenters}
+          error={optErrors.get("costCenters")}
+          disabledReason={companyReason}
+        />
+        {(
+          [
+            ["cgstAccount", "CGST account"],
+            ["sgstAccount", "SGST account"],
+            ["utgstAccount", "UTGST account"],
+            ["igstAccount", "IGST account"],
+          ] as const
+        ).map(([key, label]) => (
+          <PickField
+            key={key}
+            id={`erp-${key}`}
+            label={label}
+            value={form[key]}
+            onChange={(v) => set(key, v)}
+            items={opts.taxAccounts}
+            error={optErrors.get("taxAccounts")}
+            disabledReason={companyReason}
+            helper={key === "utgstAccount" ? "Only needed when the supplier is in a union territory without a legislature." : "Must be the account set in GST Settings."}
+          />
+        ))}
+        <TextInput
+          id="erp-paymentBank"
+          labelText="Payment bank account"
+          helperText="The bank or cash account that receives payments, e.g. HDFC Bank - AC. Needed to send payments."
+          value={form.paymentBankAccount}
+          onChange={(e) => set("paymentBankAccount", e.target.value)}
+        />
+        <TextInput
+          id="erp-tdsAccount"
+          labelText="TDS account"
+          helperText="The account that holds tax deducted by clients. Needed only for payments with TDS."
+          value={form.tdsAccount}
+          onChange={(e) => set("tdsAccount", e.target.value)}
+        />
+      </Section>
+
+      <Section title="Customers and items">
+        <TextInput
+          id="erp-defaultItem"
+          labelText="Default item code (optional)"
+          helperText="Used for invoice lines without an item code of their own; a line with none is sent as a description-only row."
+          value={form.defaultItemCode}
+          onChange={(e) => set("defaultItemCode", e.target.value)}
+        />
+        <PickField
+          id="erp-customerGroup"
+          label="Customer group for new customers"
+          value={form.customerGroup}
+          onChange={(v) => set("customerGroup", v)}
+          items={opts.customerGroups}
+          error={optErrors.get("customerGroups")}
+        />
+        <PickField
+          id="erp-territory"
+          label="Territory for new customers"
+          value={form.territory}
+          onChange={(v) => set("territory", v)}
+          items={opts.territories}
+          error={optErrors.get("territories")}
+        />
+        <PickField
+          id="erp-priceList"
+          label="Selling price list"
+          value={form.sellingPriceList}
+          onChange={(v) => set("sellingPriceList", v)}
+          items={opts.priceLists}
+          error={optErrors.get("priceLists")}
+        />
+        <fieldset className="voiced-erp__uoms">
+          <legend>Units of measure</legend>
+          <p className="voiced-muted">The ERPNext unit used for each Voiced unit. Whole-number units such as Nos reject fractional quantities.</p>
+          {UOM_UNITS.map((unit) => (
+            <PickField
+              key={unit}
+              id={`erp-uom-${unit}`}
+              label={`Voiced ${unit}`}
+              value={form.uomMap[unit] ?? ""}
+              onChange={(v) => setForm((f) => (f ? { ...f, uomMap: { ...f.uomMap, [unit]: v } } : f))}
+              items={opts.uoms}
+              error={optErrors.get("uoms")}
+            />
+          ))}
+        </fieldset>
+      </Section>
+
+      <Section title="Invoice numbers">
+        <RadioButtonGroup
+          legendText="Numbering in ERPNext"
+          name="erp-namingMode"
+          orientation="vertical"
+          valueSelected={form.namingMode}
+          onChange={(value) => set("namingMode", value === "series" ? "series" : "mirror")}
+        >
+          <RadioButton
+            id="erp-nm-mirror"
+            value="mirror"
+            labelText="Mirror the Voiced number (recommended)"
+            disabled={!mirrorOk}
+          />
+          <RadioButton id="erp-nm-series" value="series" labelText="Use an ERPNext naming series" />
+        </RadioButtonGroup>
+        <p className="voiced-muted">
+          {mirrorOk
+            ? "Mirror keeps the number printed on the PDF as the ERPNext invoice name, so GST returns match. Needs Frappe 15.73 or later."
+            : "Mirror is unavailable: this ERPNext version replaces a posted invoice number. The Voiced number is stored in the remarks instead."}
+        </p>
+        {problems.namingMode ? <p className="voiced-erp__error">{problems.namingMode}</p> : null}
+        <PickField
+          id="erp-namingSeries"
+          label="Naming series"
+          value={form.namingSeries}
+          onChange={(v) => set("namingSeries", v)}
+          items={opts.namingSeries}
+          error={problems.namingSeries ?? optErrors.get("namingSeries")}
+          disabledReason={seriesMode ? undefined : "Only used with an ERPNext naming series."}
+        />
+      </Section>
+
+      <Section title="Sending">
+        <Toggle
+          id="erp-submit"
+          labelText="Submit invoices when sending"
+          labelA="Off: drafts for review"
+          labelB="On: submitted"
+          toggled={form.submitOnPush}
+          onToggle={(v) => set("submitOnPush", v)}
+        />
+        <Toggle
+          id="erp-attach"
+          labelText="Attach the PDF"
+          labelA="Off"
+          labelB="On"
+          toggled={form.attachPdf}
+          onToggle={(v) => set("attachPdf", v)}
+        />
+        <Toggle
+          id="erp-auto"
+          labelText="Send automatically when an invoice is issued"
+          labelA="Off"
+          labelB="On"
+          toggled={form.autoPushOnIssue}
+          onToggle={(v) => set("autoPushOnIssue", v)}
+        />
+        <Toggle
+          id="erp-customers"
+          labelText="Create customers that are missing in ERPNext"
+          labelA="Off"
+          labelB="On"
+          toggled={form.createMissingCustomers}
+          onToggle={(v) => set("createMissingCustomers", v)}
+        />
+      </Section>
+
+      {saveError && !secretInvalid ? <InlineNotification kind="error" lowContrast hideCloseButton title="Not saved" subtitle={saveError} /> : null}
+      <div>
+        <Button renderIcon={Save} onClick={() => void save()} disabled={saving}>
+          {saving ? "Saving…" : "Save ERPNext settings"}
+        </Button>
+        <p className="voiced-muted">This tab has its own Save button; Save settings at the bottom of the page does not cover it.</p>
+      </div>
+    </div>
+  );
+}

src/components/SendToErpnextModal.tsx

@@ -0,0 +1,140 @@
+import { useEffect, useRef, useState } from "react";
+import { Button, InlineLoading, Modal, RadioButton, RadioButtonGroup, Tag } from "@carbon/react";
+import { api } from "../lib/api";
+import type { ErpnextPushResult } from "../lib/erpnext";
+import { describePush, failedPush, summarizeBatch } from "../lib/erpnextUi";
+import { useReturnFocus } from "../hooks/useReturnFocus";
+
+export interface SendTarget {
+  id: number;
+  number: string;
+}
+
+interface Props {
+  open: boolean;
+  invoices: SendTarget[];
+  /** Cancelled or draft invoices that were left out of the selection. */
+  skipped?: number;
+  /** The "submit on push" setting; the user still chooses explicitly. */
+  defaultSubmit: boolean;
+  onClose: () => void;
+  /** Called once when a send has finished, so the list can refresh its statuses. */
+  onFinished: (results: ErpnextPushResult[]) => void;
+}
+
+type Phase = "confirm" | "running" | "done";
+
+const TAG = { success: "green", info: "blue", warning: "warm-gray", error: "red" } as const;
+
+/** Confirm step (draft or submit), then a sequential send with progress, then per-invoice results. A failure never stops the rest. */
+export default function SendToErpnextModal({ open, invoices, skipped = 0, defaultSubmit, onClose, onFinished }: Props) {
+  const [submit, setSubmit] = useState(defaultSubmit);
+  const [phase, setPhase] = useState<Phase>("confirm");
+  const [results, setResults] = useState<ErpnextPushResult[]>([]);
+  const alive = useRef(true);
+  useReturnFocus(open);
+
+  useEffect(() => {
+    alive.current = true;
+    return () => {
+      alive.current = false;
+    };
+  }, []);
+
+  useEffect(() => {
+    if (!open) return;
+    setSubmit(defaultSubmit);
+    setPhase("confirm");
+    setResults([]);
+  }, [open, defaultSubmit]);
+
+  const run = async () => {
+    setPhase("running");
+    const out: ErpnextPushResult[] = [];
+    for (const inv of invoices) {
+      let result: ErpnextPushResult;
+      try {
+        result = await api.erpnextPushInvoice(inv.id, submit);
+      } catch (e) {
+        // Not set up, or the command itself failed: this row fails, the others still go.
+        result = failedPush(inv.id, inv.number, e);
+      }
+      out.push(result);
+      if (alive.current) setResults([...out]);
+    }
+    if (alive.current) setPhase("done");
+    onFinished(out);
+  };
+
+  const count = invoices.length;
+  const noun = count === 1 ? "invoice" : "invoices";
+
+  if (phase === "confirm") {
+    return (
+      <Modal
+        open={open}
+        modalHeading={count === 1 ? `Send ${invoices[0]?.number} to ERPNext` : `Send ${count} invoices to ERPNext`}
+        primaryButtonText={`Send ${count} ${noun}`}
+        secondaryButtonText="Cancel"
+        primaryButtonDisabled={count === 0}
+        onRequestClose={onClose}
+        onRequestSubmit={() => void run()}
+      >
+        <div className="voiced-stack">
+          <RadioButtonGroup legendText="What should ERPNext do with it?" name="erp-send-mode" orientation="vertical" valueSelected={submit ? "submit" : "draft"} onChange={(v) => setSubmit(v === "submit")}>
+            <RadioButton id="erp-send-draft" value="draft" labelText="Save as a draft for review" />
+            <RadioButton id="erp-send-submit" value="submit" labelText="Submit it (posts to the books)" />
+          </RadioButtonGroup>
+          <p className="voiced-muted">
+            An invoice that is already in ERPNext is never overwritten or created twice.
+            {skipped > 0 ? ` ${skipped} cancelled ${skipped === 1 ? "invoice is" : "invoices are"} left out: cancelled invoices are never sent.` : ""}
+          </p>
+        </div>
+      </Modal>
+    );
+  }
+
+  const summary = phase === "done" ? summarizeBatch(results) : null;
+  return (
+    <Modal
+      open={open}
+      passiveModal
+      modalHeading={phase === "running" ? "Sending to ERPNext" : "Send finished"}
+      preventCloseOnClickOutside
+      onRequestClose={() => {
+        if (phase === "done") onClose();
+      }}
+    >
+      <div className="voiced-stack">
+        {phase === "running" ? (
+          <InlineLoading description={`Sent ${results.length} of ${count}…`} />
+        ) : (
+          <p role="status">
+            <strong>{summary?.title}</strong>
+          </p>
+        )}
+        <ul className="voiced-erp__results" aria-label="Results">
+          {results.map((r) => {
+            const note = describePush(r);
+            return (
+              <li key={r.invoiceId}>
+                <Tag type={TAG[note.kind]} size="sm">
+                  {r.ok ? (r.noOp ? "Up to date" : r.remoteDocstatus === 1 ? "Submitted" : "Draft") : r.status === "conflict" ? "Conflict" : r.status === "refused" ? "Not sent" : "Error"}
+                </Tag>{" "}
+                <strong>{r.number || `#${r.invoiceId}`}</strong>
+                {r.remoteName && r.ok ? <span className="voiced-muted"> {r.remoteName}</span> : null}
+                {!r.ok && r.error ? <div className="voiced-muted">{r.error}</div> : null}
+                {r.ok && r.warnings.length > 0 ? <div className="voiced-muted">{r.warnings.join(" ")}</div> : null}
+              </li>
+            );
+          })}
+        </ul>
+        {phase === "done" ? (
+          <Button kind="primary" size="md" onClick={onClose}>
+            Close
+          </Button>
+        ) : null}
+      </div>
+    </Modal>
+  );
+}

src/hooks/useGenericExport.ts

@@ -0,0 +1,39 @@
+import { useCallback, useState } from "react";
+import { save } from "@tauri-apps/plugin-dialog";
+import { api } from "../lib/api";
+import { exportInvoicesV1, type InvoiceExportFormat } from "../lib/invoiceExportV1";
+import { useToast } from "../components/ToastProvider";
+
+/** "Export as voiced.invoice.v1": JSON or line-item CSV of the given invoices, through the save dialog. */
+export function useGenericExport(): { busy: boolean; run: (ids: number[], format: InvoiceExportFormat) => Promise<void> } {
+  const toast = useToast();
+  const [busy, setBusy] = useState(false);
+  const run = useCallback(
+    async (ids: number[], format: InvoiceExportFormat) => {
+      setBusy(true);
+      try {
+        const done = await exportInvoicesV1(
+          {
+            getInvoice: api.getInvoice,
+            listPayments: api.listPayments,
+            listClients: api.listClients,
+            getLastExportDir: api.getLastExportDir,
+            save: ({ defaultPath, format: fmt }) =>
+              save({ defaultPath, filters: [fmt === "csv" ? { name: "CSV (line items)", extensions: ["csv"] } : { name: "JSON (voiced.invoice.v1)", extensions: ["json"] }] }),
+            writeExportFile: api.writeExportFile,
+            now: () => new Date(),
+          },
+          ids,
+          format,
+        );
+        if (done) toast.success(`Exported ${done.count} ${done.count === 1 ? "invoice" : "invoices"}`, done.path);
+      } catch (e) {
+        toast.error("Could not export the invoices", String(e));
+      } finally {
+        setBusy(false);
+      }
+    },
+    [toast],
+  );
+  return { busy, run };
+}

src/lib/__golden__/invoice-v1.golden.json

@@ -0,0 +1,118 @@
+[
+  {
+    "schema": "voiced.invoice.v1",
+    "number": "INV/2026-001",
+    "issue_date": "2026-04-01",
+    "due_date": "2026-05-01",
+    "document_type": "tax_invoice",
+    "status": "issued",
+    "cancelled": false,
+    "cancelled_at": null,
+    "cancel_reason": null,
+    "currency": "INR",
+    "po_number": "PO-9",
+    "supplier": {
+      "name": "Test Vendor",
+      "address": "1 Main Rd\nPune",
+      "gstin": "27AAPFU0939F1ZV",
+      "pan": "AAPFU0939F",
+      "gst_registration": "regular",
+      "state": {
+        "code": "27",
+        "name": "Maharashtra"
+      }
+    },
+    "client": {
+      "name": "Client Ltd",
+      "gstin": "29AABCU9603R1ZJ",
+      "gst_category": "registered_regular",
+      "address": {
+        "text": "12 MG Road\nBengaluru 560001",
+        "line1": "12 MG Road",
+        "line2": null,
+        "city": "Bengaluru",
+        "pincode": "560001",
+        "state": {
+          "code": "29",
+          "name": "Karnataka"
+        }
+      },
+      "place_of_supply": {
+        "code": "29",
+        "name": "Karnataka"
+      }
+    },
+    "items": [
+      {
+        "line": 1,
+        "description": "Design",
+        "hsn_sac": "998391",
+        "quantity": "1",
+        "unit": null,
+        "rate_paise": 500010,
+        "rate": "5000.10",
+        "taxable_value_paise": 500010,
+        "taxable_value": "5000.10"
+      },
+      {
+        "line": 2,
+        "description": "Consulting",
+        "hsn_sac": null,
+        "quantity": "2",
+        "unit": "hour",
+        "rate_paise": 115505,
+        "rate": "1155.05",
+        "taxable_value_paise": 231000,
+        "taxable_value": "2310.00"
+      }
+    ],
+    "tax": {
+      "cgst": {
+        "rate": "0",
+        "amount_paise": 0,
+        "amount": "0.00"
+      },
+      "sgst": {
+        "rate": "0",
+        "amount_paise": 0,
+        "amount": "0.00"
+      },
+      "utgst": {
+        "rate": "0",
+        "amount_paise": 0,
+        "amount": "0.00"
+      },
+      "igst": {
+        "rate": "18",
+        "amount_paise": 131400,
+        "amount": "1314.00"
+      }
+    },
+    "totals": {
+      "subtotal_paise": 731010,
+      "subtotal": "7310.10",
+      "discount_paise": 1010,
+      "discount": "10.10",
+      "taxable_value_paise": 730000,
+      "taxable_value": "7300.00",
+      "tax_paise": 131400,
+      "tax": "1314.00",
+      "total_paise": 861400,
+      "total": "8614.00",
+      "amount_in_words": "Rupees Eight Thousand Six Hundred Fourteen Only"
+    },
+    "reverse_charge": false,
+    "notes": "Thank you",
+    "payments": [
+      {
+        "date": "2026-04-10",
+        "amount_paise": 700000,
+        "amount": "7000.00",
+        "tds_paise": 70000,
+        "tds": "700.00",
+        "mode": "bank_transfer",
+        "reference": "UTR123"
+      }
+    ]
+  }
+]

src/lib/api.ts

@@ -14,6 +14,15 @@ import type { LogoAsset } from "./logo";
 import type { Payment, PaymentInput } from "./payments";
 import type { BackupStatus, BackupSummary, PendingRestore } from "./backup";
 import type { LedgerRow } from "./historyExport";
+import type {
+  ErpnextConfig,
+  ErpnextConfigInput,
+  ErpnextConnectionTest,
+  ErpnextOptions,
+  ErpnextPaymentPushResult,
+  ErpnextPushResult,
+  ErpnextSyncStatus,
+} from "./erpnext";
 import type { FontInspection, ImportMeta, RemoveOutcome, UserFontRow } from "./fontImport";
 
 export interface ArchiveStatus {
@@ -113,4 +122,24 @@ export const api = {
   getBackupStatus: () => invoke<BackupStatus>("get_backup_status"),
   setAutoBackup: (enabled: boolean) => invoke<boolean>("set_auto_backup", { enabled }),
   restartApp: () => invoke<void>("restart_app"),
+
+  // ERPNext integration. All HTTP runs in Rust; the API secret is write-only from the webview.
+  erpnextGetConfig: () => invoke<ErpnextConfig>("erpnext_get_config"),
+  erpnextSaveConfig: (config: ErpnextConfigInput) => invoke<ErpnextConfig>("erpnext_save_config", { config }),
+  erpnextTestConnection: (config: ErpnextConfigInput) =>
+    invoke<ErpnextConnectionTest>("erpnext_test_connection", { config }),
+  erpnextLoadOptions: (config: ErpnextConfigInput) => invoke<ErpnextOptions>("erpnext_load_options", { config }),
+  /** `submit` omitted follows the "submit on push" setting. A failed push resolves with `ok: false`. */
+  erpnextPushInvoice: (id: number, submit?: boolean) =>
+    invoke<ErpnextPushResult>("erpnext_push_invoice", { id, submit: submit ?? null }),
+  /** One result per distinct id, in order; a failing row never stops the rest. */
+  erpnextPushInvoices: (ids: number[], submit?: boolean) =>
+    invoke<ErpnextPushResult[]>("erpnext_push_invoices", { ids, submit: submit ?? null }),
+  erpnextPushPayment: (paymentId: number) =>
+    invoke<ErpnextPaymentPushResult>("erpnext_push_payment", { paymentId }),
+  erpnextSyncStatus: (id: number) => invoke<ErpnextSyncStatus>("erpnext_sync_status", { id }),
+  /** Every invoice that has a sync row (invoices never pushed are absent). */
+  erpnextSyncStatuses: () => invoke<ErpnextSyncStatus[]>("erpnext_sync_statuses"),
+  /** `<base>/app/sales-invoice/<name>`; rejects when the invoice was never sent. */
+  erpnextOpenUrl: (id: number) => invoke<string>("erpnext_open_url", { id }),
 };

src/lib/erpnext.ts

@@ -0,0 +1,154 @@
+/** Types for the ERPNext commands (see src-tauri/src/commands/erpnext.rs); the UI helpers live in erpnextUi.ts. */
+
+export type ErpnextNamingMode = "mirror" | "series";
+
+/** What the backend returns. The API secret is never included: `apiSecretSet` says whether one is stored. */
+export interface ErpnextConfig {
+  baseUrl: string;
+  apiKey: string;
+  apiSecretSet: boolean;
+  extraCaPem: string;
+  company: string;
+  companyAddress: string;
+  namingMode: ErpnextNamingMode;
+  namingSeries: string;
+  incomeAccount: string;
+  costCenter: string;
+  cgstAccount: string;
+  sgstAccount: string;
+  utgstAccount: string;
+  igstAccount: string;
+  taxTemplateIntra: string;
+  taxTemplateInter: string;
+  paymentBankAccount: string;
+  tdsAccount: string;
+  defaultItemCode: string;
+  /** Voiced unit (second, minute, hour, session, unit) to ERPNext UOM. */
+  uomMap: Record<string, string>;
+  customerGroup: string;
+  territory: string;
+  sellingPriceList: string;
+  submitOnPush: boolean;
+  attachPdf: boolean;
+  autoPushOnIssue: boolean;
+  createMissingCustomers: boolean;
+  /** The last connection test, or null if none was stored. */
+  lastDetectResult: ErpnextConnectionTest | null;
+}
+
+/**
+ * What the webview sends to save or test. A blank `apiSecret` keeps the stored secret, a value replaces it,
+ * and `clearSecret` removes it. `lastDetectResult` omitted keeps the stored one.
+ */
+export type ErpnextConfigInput = Omit<ErpnextConfig, "apiSecretSet" | "lastDetectResult"> & {
+  apiSecret: string;
+  clearSecret?: boolean;
+  lastDetectResult?: ErpnextConnectionTest | null;
+};
+
+export interface ErpnextWarning {
+  code: string;
+  message: string;
+}
+
+export interface ErpnextVersions {
+  frappe: string | null;
+  erpnext: string | null;
+  indiaCompliance: string | null;
+}
+
+export interface ErpnextConnectionTest {
+  user: string;
+  versions: ErpnextVersions;
+  features: { v2Naming: boolean; indiaCompliance: boolean };
+  indiaCompliance: boolean;
+  warnings: ErpnextWarning[];
+}
+
+export interface ErpnextOptionItem {
+  /** The value to store (the document name). */
+  name: string;
+  label: string;
+  detail: string;
+}
+
+export interface ErpnextOptions {
+  companies: ErpnextOptionItem[];
+  companyAddresses: ErpnextOptionItem[];
+  incomeAccounts: ErpnextOptionItem[];
+  taxAccounts: ErpnextOptionItem[];
+  taxTemplates: ErpnextOptionItem[];
+  namingSeries: ErpnextOptionItem[];
+  itemGroups: ErpnextOptionItem[];
+  uoms: ErpnextOptionItem[];
+  costCenters: ErpnextOptionItem[];
+  priceLists: ErpnextOptionItem[];
+  customerGroups: ErpnextOptionItem[];
+  territories: ErpnextOptionItem[];
+  /** Lists that failed to load; the others are still filled. */
+  errors: { list: string; message: string }[];
+}
+
+export type ErpnextErrorKind =
+  | "auth"
+  | "permission"
+  | "not_found"
+  | "duplicate"
+  | "validation"
+  | "rate_limit"
+  | "server"
+  | "timeout"
+  | "network"
+  | "config"
+  | "protocol"
+  | "conflict"
+  | "precondition"
+  | "other";
+
+/** `refused`: nothing was sent and nothing was recorded (a draft or cancelled invoice). */
+export type ErpnextPushStatus = "synced" | "error" | "conflict" | "refused";
+
+export interface ErpnextPushResult {
+  invoiceId: number;
+  number: string;
+  ok: boolean;
+  status: ErpnextPushStatus;
+  remoteName: string;
+  /** 0 draft, 1 submitted. */
+  remoteDocstatus: number;
+  /** Created by this call, not found already there. */
+  created: boolean;
+  /** Already synced with the same payload; nothing was done. */
+  noOp: boolean;
+  /** The archived PDF is attached on the remote document. */
+  attached: boolean;
+  error: string | null;
+  errorKind: ErpnextErrorKind | null;
+  /** Non-fatal notes, e.g. sent without the PDF because the invoice is not archived. */
+  warnings: string[];
+}
+
+export interface ErpnextPaymentPushResult {
+  paymentId: number;
+  invoiceId: number;
+  ok: boolean;
+  entryName: string | null;
+  /** Sent earlier; nothing was posted. */
+  alreadySynced: boolean;
+  error: string | null;
+  errorKind: ErpnextErrorKind | null;
+}
+
+/** `none` until something was pushed. */
+export type ErpnextSyncState = "none" | "pending" | "synced" | "error" | "conflict";
+
+export interface ErpnextSyncStatus {
+  invoiceId: number;
+  status: ErpnextSyncState;
+  remoteName: string;
+  /** 0 draft, 1 submitted. */
+  remoteDocstatus: number;
+  lastError: string;
+  syncedAt: string | null;
+  attached: boolean;
+}

src/lib/erpnextActions.ts

@@ -0,0 +1,7 @@
+import { openUrl } from "@tauri-apps/plugin-opener";
+import { api } from "./api";
+
+/** Opens the invoice's ERPNext page in the system browser (`<base>/app/sales-invoice/<name>`); rejects if it was never sent. */
+export async function openInErpnext(invoiceId: number): Promise<void> {
+  await openUrl(await api.erpnextOpenUrl(invoiceId));
+}

src/lib/erpnextUi.test.ts

@@ -0,0 +1,286 @@
+import { describe, expect, it, vi } from "vitest";
+import type { ErpnextConfig, ErpnextConnectionTest, ErpnextPushResult, ErpnextSyncStatus } from "./erpnext";
+import {
+  autoPushIssued,
+  baseUrlProblem,
+  connectionProblems,
+  describePaymentPush,
+  describePush,
+  failedPush,
+  hasDetectResult,
+  isConfigured,
+  paymentPushDisabledReason,
+  pushDisabledReason,
+  summarizeBatch,
+  syncTag,
+  toInput,
+  validateConfigForm,
+  warningSeverity,
+  withDefaultUoms,
+  withStoredValue,
+  sortWarnings,
+  sendableSelection,
+  formatSyncedAt,
+} from "./erpnextUi";
+
+const test: ErpnextConnectionTest = {
+  user: "api@example.com",
+  versions: { frappe: "15.80.0", erpnext: "15.70.0", indiaCompliance: "15.30.0" },
+  features: { v2Naming: true, indiaCompliance: true },
+  indiaCompliance: true,
+  warnings: [],
+};
+
+const config = (patch: Partial<ErpnextConfig> = {}): ErpnextConfig => ({
+  baseUrl: "https://erp.example.com",
+  apiKey: "key",
+  apiSecretSet: true,
+  extraCaPem: "",
+  company: "Test Co",
+  companyAddress: "",
+  namingMode: "mirror",
+  namingSeries: "",
+  incomeAccount: "",
+  costCenter: "",
+  cgstAccount: "",
+  sgstAccount: "",
+  utgstAccount: "",
+  igstAccount: "",
+  taxTemplateIntra: "",
+  taxTemplateInter: "",
+  paymentBankAccount: "",
+  tdsAccount: "",
+  defaultItemCode: "",
+  uomMap: {},
+  customerGroup: "",
+  territory: "",
+  sellingPriceList: "",
+  submitOnPush: false,
+  attachPdf: true,
+  autoPushOnIssue: false,
+  createMissingCustomers: true,
+  lastDetectResult: test,
+  ...patch,
+});
+
+const sync = (patch: Partial<ErpnextSyncStatus>): ErpnextSyncStatus => ({
+  invoiceId: 1,
+  status: "synced",
+  remoteName: "INV/2026-001",
+  remoteDocstatus: 0,
+  lastError: "",
+  syncedAt: null,
+  attached: false,
+  ...patch,
+});
+
+const push = (patch: Partial<ErpnextPushResult> = {}): ErpnextPushResult => ({
+  invoiceId: 1,
+  number: "INV/2026-001",
+  ok: true,
+  status: "synced",
+  remoteName: "INV/2026-001",
+  remoteDocstatus: 0,
+  created: true,
+  noOp: false,
+  attached: true,
+  error: null,
+  errorKind: null,
+  warnings: [],
+  ...patch,
+});
+
+describe("status tags", () => {
+  it("maps every sync state", () => {
+    expect(syncTag(undefined)).toMatchObject({ label: "Not sent", type: "gray" });
+    expect(syncTag(sync({ status: "none" })).label).toBe("Not sent");
+    expect(syncTag(sync({ remoteDocstatus: 0 }))).toMatchObject({ label: "Draft in ERPNext", type: "blue" });
+    expect(syncTag(sync({ remoteDocstatus: 1 }))).toMatchObject({ label: "Submitted", type: "green" });
+    expect(syncTag(sync({ status: "error", lastError: "Item missing" }))).toMatchObject({ label: "Error", type: "red", tooltip: "Item missing" });
+    expect(syncTag(sync({ status: "conflict", lastError: "" }))).toMatchObject({ label: "Conflict", type: "purple" });
+    expect(syncTag(sync({ status: "error", lastError: "" })).tooltip).toBeTruthy();
+  });
+});
+
+describe("configured and disabled reasons", () => {
+  it("needs an address, a key and a stored secret", () => {
+    expect(isConfigured(config())).toBe(true);
+    expect(isConfigured(config({ baseUrl: " " }))).toBe(false);
+    expect(isConfigured(config({ apiKey: "" }))).toBe(false);
+    expect(isConfigured(config({ apiSecretSet: false }))).toBe(false);
+    expect(isConfigured(null)).toBe(false);
+  });
+
+  it("asks for a connection test only when the vendor is registered", () => {
+    const untested = config({ lastDetectResult: null });
+    expect(pushDisabledReason({ cfg: untested, vendorRegistered: true })).toMatch(/Run Test connection first/);
+    expect(pushDisabledReason({ cfg: untested, vendorRegistered: false })).toBeNull();
+    expect(pushDisabledReason({ cfg: config(), vendorRegistered: true })).toBeNull();
+    expect(hasDetectResult(null)).toBe(false);
+    expect(hasDetectResult({} as ErpnextConnectionTest)).toBe(false);
+    expect(pushDisabledReason({ cfg: null, vendorRegistered: false })).toMatch(/not set up/);
+    expect(pushDisabledReason({ cfg: config(), vendorRegistered: false, invoiceStatus: "cancelled" })).toMatch(/Cancelled/);
+    expect(pushDisabledReason({ cfg: config(), vendorRegistered: false, invoiceStatus: "issued" })).toBeNull();
+  });
+
+  it("allows a payment only against a submitted invoice, once", () => {
+    const cfg = config();
+    expect(paymentPushDisabledReason({ cfg, sync: undefined, entry: null })).toMatch(/Send the invoice/);
+    expect(paymentPushDisabledReason({ cfg, sync: sync({ remoteDocstatus: 0 }), entry: null })).toMatch(/Submit the invoice in ERPNext first/);
+    expect(paymentPushDisabledReason({ cfg, sync: sync({ remoteDocstatus: 1 }), entry: null })).toBeNull();
+    expect(paymentPushDisabledReason({ cfg, sync: sync({ remoteDocstatus: 1 }), entry: "ACC-PAY-1" })).toMatch(/ACC-PAY-1/);
+  });
+});
+
+describe("push results", () => {
+  it("describes outcomes", () => {
+    expect(describePush(push())).toMatchObject({ kind: "success", subtitle: "INV/2026-001 (draft)" });
+    expect(describePush(push({ remoteDocstatus: 1 })).subtitle).toContain("submitted");
+    expect(describePush(push({ noOp: true })).kind).toBe("info");
+    const warned = describePush(push({ warnings: ["The PDF was not attached: no permission"] }));
+    expect(warned.kind).toBe("warning");
+    expect(warned.subtitle).toContain("no permission");
+    expect(describePush(push({ ok: false, status: "refused", error: "Run Test connection first", errorKind: "precondition" })).kind).toBe("warning");
+    expect(describePush(push({ ok: false, status: "conflict", error: "different total" })).title).toMatch(/conflicts/);
+    expect(describePush(push({ ok: false, status: "error", error: "417", errorKind: "validation" })).kind).toBe("error");
+    expect(describePaymentPush({ paymentId: 1, invoiceId: 1, ok: true, entryName: "PE-1", alreadySynced: false, error: null, errorKind: null }).kind).toBe("success");
+    expect(describePaymentPush({ paymentId: 1, invoiceId: 1, ok: false, entryName: null, alreadySynced: false, error: "nope", errorKind: "other" }).kind).toBe("error");
+  });
+
+  it("turns a rejected call into a failed row", () => {
+    const r = failedPush(3, "INV/3", "ERPNext is not set up yet");
+    expect(r).toMatchObject({ ok: false, invoiceId: 3, number: "INV/3", error: "ERPNext is not set up yet" });
+    expect(failedPush(3, "INV/3", new Error("boom")).error).toBe("boom");
+  });
+
+  it("summarises a batch", () => {
+    const s = summarizeBatch([push(), push({ noOp: true }), push({ ok: false, status: "error", error: "x" })]);
+    expect(s).toMatchObject({ total: 3, sent: 1, upToDate: 1, failed: 1, kind: "warning" });
+    expect(s.title).toBe("1 sent, 1 already up to date, 1 failed");
+    expect(summarizeBatch([push(), push()]).kind).toBe("success");
+    expect(summarizeBatch([push({ ok: false })]).kind).toBe("error");
+    expect(summarizeBatch([push({ warnings: ["w"] })]).kind).toBe("warning");
+  });
+});
+
+describe("auto push on issue", () => {
+  const invoice = { id: 7, number: "INV/2026-007" };
+
+  it("does nothing when it is off or ERPNext is not set up", async () => {
+    const pushFn = vi.fn();
+    expect(await autoPushIssued({ getConfig: async () => config(), push: pushFn }, invoice, true)).toBeNull();
+    expect(await autoPushIssued({ getConfig: async () => config({ autoPushOnIssue: true, apiSecretSet: false }), push: pushFn }, invoice, true)).toBeNull();
+    expect(await autoPushIssued({ getConfig: async () => Promise.reject(new Error("db")), push: pushFn }, invoice, true)).toBeNull();
+    expect(pushFn).not.toHaveBeenCalled();
+  });
+
+  it("pushes with the configured submit setting and reports the result", async () => {
+    const pushFn = vi.fn(async () => push({ number: invoice.number }));
+    const notice = await autoPushIssued({ getConfig: async () => config({ autoPushOnIssue: true }), push: pushFn }, invoice, true);
+    expect(pushFn).toHaveBeenCalledWith(7);
+    expect(notice?.kind).toBe("success");
+  });
+
+  it("never throws: a rejected push becomes an error notice", async () => {
+    const notice = await autoPushIssued(
+      { getConfig: async () => config({ autoPushOnIssue: true }), push: async () => Promise.reject("ERPNext is not set up yet") },
+      invoice,
+      false,
+    );
+    expect(notice).toMatchObject({ kind: "error" });
+    expect(notice?.subtitle).toContain("not set up");
+  });
+
+  it("explains a missing connection test instead of pushing", async () => {
+    const pushFn = vi.fn();
+    const notice = await autoPushIssued({ getConfig: async () => config({ autoPushOnIssue: true, lastDetectResult: null }), push: pushFn }, invoice, true);
+    expect(pushFn).not.toHaveBeenCalled();
+    expect(notice?.subtitle).toMatch(/Run Test connection first/);
+  });
+});
+
+describe("warnings", () => {
+  it("ranks errors before warnings before notes", () => {
+    expect(warningSeverity("gst_accounts_not_configured")).toBe("error");
+    expect(warningSeverity("ic_not_detected")).toBe("warning");
+    expect(warningSeverity("versions_unknown")).toBe("info");
+    const sorted = sortWarnings([
+      { code: "versions_unknown", message: "a" },
+      { code: "company_missing", message: "b" },
+      { code: "ic_not_detected", message: "c" },
+    ]);
+    expect(sorted.map((w) => w.code)).toEqual(["company_missing", "ic_not_detected", "versions_unknown"]);
+  });
+});
+
+describe("settings form", () => {
+  it("validates the address like the backend", () => {
+    expect(baseUrlProblem("")).toMatch(/Enter/);
+    expect(baseUrlProblem("https://erp.example.com")).toBeNull();
+    expect(baseUrlProblem("erp.example.com")).toBeNull();
+    expect(baseUrlProblem("http://erp.example.com")).toMatch(/https/);
+    expect(baseUrlProblem("http://localhost:8000")).toBeNull();
+    expect(baseUrlProblem("localhost:8000")).toBeNull();
+    expect(baseUrlProblem("http://site.test")).toBeNull();
+    expect(baseUrlProblem("http://127.0.0.1:8000")).toBeNull();
+    expect(baseUrlProblem("https://user:pw@erp.example.com")).toMatch(/credentials/);
+    expect(baseUrlProblem("ftp://erp.example.com")).toMatch(/https/);
+  });
+
+  it("builds the input without write-only fields and fills the UOM defaults", () => {
+    const input = toInput(config({ uomMap: { hour: "Hr" } }));
+    expect(input).not.toHaveProperty("apiSecretSet");
+    expect(input).not.toHaveProperty("lastDetectResult");
+    expect(input.apiSecret).toBe("");
+    expect(input.uomMap).toEqual({ second: "Second", minute: "Minute", hour: "Hr", session: "Nos", unit: "Nos" });
+    expect(withDefaultUoms({ hour: " " }).hour).toBe("Hour");
+  });
+
+  it("needs a secret only when none is stored or it is being cleared", () => {
+    const form = toInput(config());
+    expect(connectionProblems(form, true)).toEqual({});
+    expect(connectionProblems(form, false).apiSecret).toBeTruthy();
+    expect(connectionProblems({ ...form, clearSecret: true }, true).apiSecret).toBeTruthy();
+    expect(connectionProblems({ ...form, clearSecret: true, apiSecret: "new" }, true)).toEqual({});
+    expect(connectionProblems({ ...form, apiKey: " " }, true).apiKey).toBeTruthy();
+  });
+
+  it("validates a save: untouched is fine, series mode needs a series, mirror needs v2 naming", () => {
+    const empty = toInput(config({ baseUrl: "", apiKey: "", apiSecretSet: false }));
+    expect(validateConfigForm(empty, false, null)).toEqual({});
+    const form = toInput(config());
+    expect(validateConfigForm(form, true, test)).toEqual({});
+    expect(validateConfigForm({ ...form, namingMode: "series", namingSeries: "" }, true, test).namingSeries).toBeTruthy();
+    expect(validateConfigForm({ ...form, namingMode: "series", namingSeries: "SINV-.YY.-" }, true, test)).toEqual({});
+    const old = { ...test, features: { v2Naming: false, indiaCompliance: true } };
+    expect(validateConfigForm(form, true, old).namingMode).toBeTruthy();
+    expect(validateConfigForm(form, true, null).namingMode).toBeUndefined();
+  });
+
+  it("keeps a saved value visible when the loaded list lacks it", () => {
+    const items = [{ name: "A", label: "A", detail: "" }];
+    expect(withStoredValue(items, "A")).toBe(items);
+    expect(withStoredValue(items, "")).toBe(items);
+    const out = withStoredValue(items, "Sales - AC");
+    expect(out[0]).toMatchObject({ name: "Sales - AC" });
+    expect(out).toHaveLength(2);
+  });
+});
+
+describe("selection and dates", () => {
+  it("leaves cancelled invoices out of a send", () => {
+    const rows = [
+      { id: 1, status: "issued" },
+      { id: 2, status: "cancelled" },
+      { id: 3, status: "issued" },
+    ];
+    expect(sendableSelection(rows)).toEqual({ send: [rows[0], rows[2]], skipped: 1 });
+    expect(sendableSelection([])).toEqual({ send: [], skipped: 0 });
+  });
+
+  it("formats the sync time defensively", () => {
+    expect(formatSyncedAt(null)).toBe("");
+    expect(formatSyncedAt("not a date")).toBe("not a date");
+    expect(formatSyncedAt("2026-04-01T10:30:00+00:00")).toMatch(/2026/);
+  });
+});

src/lib/erpnextUi.ts

@@ -0,0 +1,390 @@
+/** Pure helpers behind the ERPNext screens (Settings, History, invoice detail, auto-push). No UI, no Tauri. */
+import type {
+  ErpnextConfig,
+  ErpnextConfigInput,
+  ErpnextConnectionTest,
+  ErpnextOptionItem,
+  ErpnextOptions,
+  ErpnextPaymentPushResult,
+  ErpnextPushResult,
+  ErpnextSyncStatus,
+  ErpnextWarning,
+} from "./erpnext";
+
+export type TagColor = "red" | "green" | "blue" | "gray" | "purple" | "cool-gray" | "warm-gray";
+export type NoticeKind = "success" | "info" | "warning" | "error";
+
+export const SETTINGS_LINK_TEXT = "Settings, Integrations";
+
+// ---- configuration state ----
+
+/** Enough saved to try a push: address, key and a stored secret. */
+export function isConfigured(cfg: Pick<ErpnextConfig, "baseUrl" | "apiKey" | "apiSecretSet"> | null | undefined): boolean {
+  return Boolean(cfg && cfg.baseUrl.trim() && cfg.apiKey.trim() && cfg.apiSecretSet);
+}
+
+/** True when a connection test result is stored (the backend refuses a registered vendor's push without one). */
+export function hasDetectResult(result: ErpnextConnectionTest | null | undefined): boolean {
+  return Boolean(result && typeof result === "object" && Object.keys(result).length > 0);
+}
+
+export const NOT_CONFIGURED_REASON = "ERPNext is not set up. Enter the address, API key and secret in Settings, Integrations.";
+export const RUN_TEST_REASON = "Run Test connection first (Settings, Integrations).";
+
+/**
+ * Why an invoice cannot be sent right now, or null. The backend applies the same registered-vendor rule using the
+ * supplier snapshot frozen on the invoice; the current GST registration setting is the proxy here.
+ */
+export function pushDisabledReason(opts: {
+  cfg: ErpnextConfig | null;
+  vendorRegistered: boolean;
+  invoiceStatus?: string;
+}): string | null {
+  if (!isConfigured(opts.cfg)) return NOT_CONFIGURED_REASON;
+  if (opts.invoiceStatus !== undefined && opts.invoiceStatus !== "issued") {
+    return opts.invoiceStatus === "cancelled"
+      ? "Cancelled invoices are never sent to ERPNext."
+      : "Only issued invoices are sent to ERPNext.";
+  }
+  if (opts.vendorRegistered && !hasDetectResult(opts.cfg?.lastDetectResult)) return RUN_TEST_REASON;
+  return null;
+}
+
+/** A payment can be posted only against a submitted invoice, once. */
+export function paymentPushDisabledReason(opts: {
+  cfg: ErpnextConfig | null;
+  sync: ErpnextSyncStatus | undefined;
+  entry: string | null | undefined;
+}): string | null {
+  if (!isConfigured(opts.cfg)) return NOT_CONFIGURED_REASON;
+  if (opts.entry) return `Already sent as ${opts.entry}.`;
+  if (!opts.sync || opts.sync.status !== "synced") return "Send the invoice to ERPNext first.";
+  if (opts.sync.remoteDocstatus !== 1) return "Submit the invoice in ERPNext first.";
+  return null;
+}
+
+// ---- sync status ----
+
+export interface SyncTag {
+  label: string;
+  type: TagColor;
+  /** Hover text: the stored error for a failure. */
+  tooltip?: string;
+}
+
+export function syncTag(s: ErpnextSyncStatus | undefined): SyncTag {
+  if (!s || s.status === "none") return { label: "Not sent", type: "gray" };
+  switch (s.status) {
+    case "synced":
+      return s.remoteDocstatus === 1
+        ? { label: "Submitted", type: "green", tooltip: s.remoteName || undefined }
+        : { label: "Draft in ERPNext", type: "blue", tooltip: s.remoteName || undefined };
+    case "error":
+      return { label: "Error", type: "red", tooltip: s.lastError || "The last send failed." };
+    case "conflict":
+      return { label: "Conflict", type: "purple", tooltip: s.lastError || "ERPNext already has a different document with this name." };
+    case "pending":
+      return { label: "Sending", type: "warm-gray" };
+    default:
+      return { label: "Not sent", type: "gray" };
+  }
+}
+
+export function indexSyncStatuses(list: ErpnextSyncStatus[]): Map<number, ErpnextSyncStatus> {
+  return new Map(list.map((s) => [s.invoiceId, s]));
+}
+
+/** Rows that have an ERPNext document to open. */
+export const canOpenInErpnext = (s: ErpnextSyncStatus | undefined): boolean => Boolean(s && s.remoteName);
+
+/** Stored sync time (RFC 3339) for display; the raw text if it cannot be parsed, blank if there is none. */
+export function formatSyncedAt(iso: string | null | undefined): string {
+  if (!iso) return "";
+  const d = new Date(iso);
+  return Number.isNaN(d.getTime()) ? iso : d.toLocaleString("en-GB", { day: "2-digit", month: "short", year: "numeric", hour: "2-digit", minute: "2-digit" });
+}
+
+/** From a selection: the issued invoices that can be sent, and how many were left out (cancelled or draft). */
+export function sendableSelection<T extends { status: string }>(rows: T[]): { send: T[]; skipped: number } {
+  const send = rows.filter((r) => r.status === "issued");
+  return { send, skipped: rows.length - send.length };
+}
+
+// ---- push results ----
+
+export interface Notice {
+  kind: NoticeKind;
+  title: string;
+  subtitle?: string;
+}
+
+const docState = (docstatus: number) => (docstatus === 1 ? "submitted" : "draft");
+
+/** One push outcome as a toast. Warnings turn a success into a warning toast so they are read. */
+export function describePush(r: ErpnextPushResult): Notice {
+  if (r.ok) {
+    const where = `${r.remoteName} (${docState(r.remoteDocstatus)})`;
+    if (r.warnings.length > 0) {
+      return { kind: "warning", title: `Invoice ${r.number} sent to ERPNext with notes`, subtitle: [where, ...r.warnings].join(" ") };
+    }
+    if (r.noOp) return { kind: "info", title: `Invoice ${r.number} is already up to date in ERPNext`, subtitle: where };
+    return { kind: "success", title: `Invoice ${r.number} sent to ERPNext`, subtitle: where };
+  }
+  if (r.status === "refused" || r.errorKind === "precondition" || r.errorKind === "config") {
+    return { kind: "warning", title: `Invoice ${r.number || r.invoiceId} was not sent`, subtitle: r.error ?? undefined };
+  }
+  if (r.status === "conflict") {
+    return { kind: "error", title: `Invoice ${r.number} conflicts with ERPNext`, subtitle: r.error ?? undefined };
+  }
+  return { kind: "error", title: `Could not send invoice ${r.number || r.invoiceId}`, subtitle: r.error ?? undefined };
+}
+
+export function describePaymentPush(r: ErpnextPaymentPushResult): Notice {
+  if (r.ok) {
+    return r.alreadySynced
+      ? { kind: "info", title: "Payment was already sent", subtitle: r.entryName ?? undefined }
+      : { kind: "success", title: "Payment sent to ERPNext", subtitle: r.entryName ?? undefined };
+  }
+  return { kind: "error", title: "Could not send the payment", subtitle: r.error ?? undefined };
+}
+
+/** A rejected invoke (for example "ERPNext is not set up yet") turned into a result row, so a batch carries on. */
+export function failedPush(invoiceId: number, number: string, error: unknown): ErpnextPushResult {
+  return {
+    invoiceId,
+    number,
+    ok: false,
+    status: "error",
+    remoteName: "",
+    remoteDocstatus: 0,
+    created: false,
+    noOp: false,
+    attached: false,
+    error: error instanceof Error ? error.message : String(error),
+    errorKind: "other",
+    warnings: [],
+  };
+}
+
+export interface BatchSummary {
+  total: number;
+  sent: number;
+  upToDate: number;
+  failed: number;
+  withNotes: number;
+  kind: NoticeKind;
+  title: string;
+}
+
+export function summarizeBatch(results: ErpnextPushResult[]): BatchSummary {
+  const failed = results.filter((r) => !r.ok).length;
+  const upToDate = results.filter((r) => r.ok && r.noOp && r.warnings.length === 0).length;
+  const sent = results.filter((r) => r.ok).length - upToDate;
+  const withNotes = results.filter((r) => r.ok && r.warnings.length > 0).length;
+  const kind: NoticeKind = failed > 0 ? (failed === results.length ? "error" : "warning") : withNotes > 0 ? "warning" : "success";
+  const parts = [`${sent} sent`];
+  if (upToDate > 0) parts.push(`${upToDate} already up to date`);
+  if (failed > 0) parts.push(`${failed} failed`);
+  return { total: results.length, sent, upToDate, failed, withNotes, kind, title: parts.join(", ") };
+}
+
+// ---- auto-push after issue ----
+
+export interface AutoPushDeps {
+  getConfig(): Promise<ErpnextConfig>;
+  push(id: number, submit?: boolean): Promise<ErpnextPushResult>;
+}
+
+/**
+ * Pushes a just-issued invoice when "send on issue" is on. Never throws and never blocks the issue: anything that
+ * goes wrong comes back as a notice. Returns null when nothing was attempted (off, or not set up).
+ */
+export async function autoPushIssued(
+  deps: AutoPushDeps,
+  invoice: { id: number; number: string },
+  vendorRegistered: boolean,
+): Promise<Notice | null> {
+  let cfg: ErpnextConfig;
+  try {
+    cfg = await deps.getConfig();
+  } catch {
+    return null;
+  }
+  if (!cfg.autoPushOnIssue || !isConfigured(cfg)) return null;
+  const blocked = pushDisabledReason({ cfg, vendorRegistered });
+  if (blocked) return { kind: "warning", title: `Invoice ${invoice.number} was not sent to ERPNext`, subtitle: blocked };
+  try {
+    return describePush(await deps.push(invoice.id));
+  } catch (e) {
+    return describePush(failedPush(invoice.id, invoice.number, e));
+  }
+}
+
+// ---- connection test display ----
+
+const ERROR_CODES = new Set([
+  "company_missing",
+  "company_address_missing",
+  "income_account_missing",
+  "tax_accounts_missing",
+  "naming_series_missing",
+  "naming_series_too_long",
+  "number_invalid",
+  "mirror_unsupported",
+  "gst_accounts_not_configured",
+]);
+const INFO_CODES = new Set(["versions_unknown", "gst_settings_unreadable"]);
+
+/** How loudly a test warning is shown: the ones that would make invoices land wrong are errors. */
+export function warningSeverity(code: string): "error" | "warning" | "info" {
+  if (ERROR_CODES.has(code)) return "error";
+  if (INFO_CODES.has(code)) return "info";
+  return "warning";
+}
+
+export function sortWarnings(list: ErpnextWarning[]): ErpnextWarning[] {
+  const rank = { error: 0, warning: 1, info: 2 } as const;
+  return [...list].sort((a, b) => rank[warningSeverity(a.code)] - rank[warningSeverity(b.code)]);
+}
+
+export function versionsLine(test: ErpnextConnectionTest): string {
+  const v = test.versions;
+  const parts = [
+    `Frappe ${v.frappe ?? "unknown"}`,
+    `ERPNext ${v.erpnext ?? "unknown"}`,
+    test.indiaCompliance ? `India Compliance ${v.indiaCompliance ?? "installed"}` : "India Compliance not detected",
+  ];
+  return parts.join(" · ");
+}
+
+// ---- settings form ----
+
+export const UOM_UNITS = ["second", "minute", "hour", "session", "unit"] as const;
+export const DEFAULT_UOM_MAP: Record<string, string> = {
+  second: "Second",
+  minute: "Minute",
+  hour: "Hour",
+  session: "Nos",
+  unit: "Nos",
+};
+
+export function withDefaultUoms(map: Record<string, string> | undefined): Record<string, string> {
+  const out: Record<string, string> = { ...DEFAULT_UOM_MAP };
+  for (const [k, v] of Object.entries(map ?? {})) if (v.trim()) out[k] = v;
+  return out;
+}
+
+/** What the form edits: the saved config minus the write-only fields, plus the secret being typed. */
+export function toInput(cfg: ErpnextConfig): ErpnextConfigInput {
+  const { apiSecretSet: _set, lastDetectResult: _last, ...rest } = cfg;
+  void _set;
+  void _last;
+  return { ...rest, uomMap: withDefaultUoms(rest.uomMap), apiSecret: "", clearSecret: false };
+}
+
+/** Mirror mode needs a Frappe that keeps a posted name; an untested site defaults to it (the backend default). */
+export function mirrorSupported(test: ErpnextConnectionTest | null): boolean {
+  return test ? test.features.v2Naming : true;
+}
+
+export function isLocalDevHost(host: string): boolean {
+  const h = host.replace(/\.$/, "").toLowerCase();
+  return h === "localhost" || h === "127.0.0.1" || h.endsWith(".localhost") || h.endsWith(".test");
+}
+
+/** Same rules as the backend's address check, so a bad address is caught before the round trip. */
+export function baseUrlProblem(raw: string): string | null {
+  const text = raw.trim();
+  if (!text) return "Enter the address of your ERPNext site.";
+  const withScheme = text.includes("://") ? text : `${isLocalDevHost(text.split(/[/:]/)[0] ?? "") ? "http" : "https"}://${text}`;
+  let url: URL;
+  try {
+    url = new URL(withScheme);
+  } catch {
+    return "This is not a valid address, e.g. https://erp.example.com";
+  }
+  if (url.protocol !== "https:" && url.protocol !== "http:") return "Use an https:// address.";
+  if (url.protocol === "http:" && !isLocalDevHost(url.hostname)) {
+    return "Use an https:// address. Plain http is only allowed for localhost, 127.0.0.1, *.localhost and *.test.";
+  }
+  if (url.username || url.password) return "Do not put credentials in the address; use the API key and secret fields.";
+  return null;
+}
+
+export interface FormProblems {
+  baseUrl?: string;
+  apiKey?: string;
+  apiSecret?: string;
+  company?: string;
+  namingSeries?: string;
+  namingMode?: string;
+}
+
+/** Problems that stop a Test connection (address, key, secret). */
+export function connectionProblems(form: ErpnextConfigInput, secretStored: boolean): FormProblems {
+  const p: FormProblems = {};
+  const url = baseUrlProblem(form.baseUrl);
+  if (url) p.baseUrl = url;
+  if (!form.apiKey.trim()) p.apiKey = "Enter the API key.";
+  if (!form.apiSecret.trim() && (form.clearSecret || !secretStored)) p.apiSecret = "Enter the API secret.";
+  return p;
+}
+
+/** Problems that stop a Save. An empty form (nothing set up) saves fine; a half-filled one does not. */
+export function validateConfigForm(form: ErpnextConfigInput, secretStored: boolean, test: ErpnextConnectionTest | null): FormProblems {
+  const touched = form.baseUrl.trim() || form.apiKey.trim() || form.apiSecret.trim() || secretStored;
+  if (!touched) return {};
+  const p = connectionProblems(form, secretStored);
+  if (form.namingMode === "series" && !form.namingSeries.trim()) p.namingSeries = "Choose or enter the naming series.";
+  if (form.namingMode === "mirror" && !mirrorSupported(test)) {
+    p.namingMode = "This ERPNext version does not keep a posted invoice number. Use ERPNext series.";
+  }
+  return p;
+}
+
+export const hasProblems = (p: FormProblems): boolean => Object.keys(p).length > 0;
+
+/** Options for a dropdown, with the saved value kept visible when the loaded list does not contain it. */
+export function withStoredValue(items: ErpnextOptionItem[], stored: string): ErpnextOptionItem[] {
+  const value = stored.trim();
+  if (!value || items.some((i) => i.name === value)) return items;
+  return [{ name: value, label: value, detail: "saved value, not in the loaded list" }, ...items];
+}
+
+export const optionText = (i: ErpnextOptionItem): string => (i.detail ? `${i.label} (${i.detail})` : i.label);
+
+export const OPTION_LIST_LABELS: Record<string, string> = {
+  companies: "Companies",
+  companyAddresses: "Company addresses",
+  incomeAccounts: "Income accounts",
+  taxAccounts: "Tax accounts",
+  taxTemplates: "Tax templates",
+  namingSeries: "Naming series",
+  itemGroups: "Item groups",
+  uoms: "Units of measure",
+  costCenters: "Cost centers",
+  priceLists: "Price lists",
+  customerGroups: "Customer groups",
+  territories: "Territories",
+};
+
+/** Per-list load errors keyed by list name; the other lists stay usable. */
+export function optionErrors(options: ErpnextOptions | null): Map<string, string> {
+  return new Map((options?.errors ?? []).map((e) => [e.list, e.message]));
+}
+
+export const emptyOptions = (): ErpnextOptions => ({
+  companies: [],
+  companyAddresses: [],
+  incomeAccounts: [],
+  taxAccounts: [],
+  taxTemplates: [],
+  namingSeries: [],
+  itemGroups: [],
+  uoms: [],
+  costCenters: [],
+  priceLists: [],
+  customerGroups: [],
+  territories: [],
+  errors: [],
+});

src/lib/historyExport.ts

@@ -154,7 +154,7 @@ export interface HistoryExportDeps {
   now(): Date;
 }
 
-function joinPath(dir: string, name: string): string {
+export function joinPath(dir: string, name: string): string {
   if (!dir) return name;
   if (/[\\/]$/.test(dir)) return `${dir}${name}`;
   return `${dir}${dir.includes("\\") && !dir.includes("/") ? "\\" : "/"}${name}`;

src/lib/invoiceExportV1.test.ts

@@ -0,0 +1,311 @@
+import { readFileSync, writeFileSync, existsSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+import {
+  buildInvoiceDoc,
+  exportInvoicesV1,
+  invoiceExportName,
+  LINE_CSV_HEADERS,
+  loadInvoiceDocs,
+  rateString,
+  rupeesToPaise,
+  toInvoiceJson,
+  toLineItemsCsv,
+  type InvoiceExportDeps,
+} from "./invoiceExportV1";
+import type { Payment } from "./payments";
+import { blankClient, type Client, type Invoice } from "./types";
+
+const VENDOR = (patch: Record<string, unknown> = {}) =>
+  JSON.stringify({
+    vendorName: "Test Vendor",
+    vendorAddress: "1 Main Rd\nPune",
+    vendorEmail: "a@example.com",
+    vendorPhone: "999",
+    vendorPan: "AAPFU0939F",
+    vendorGstin: "27AAPFU0939F1ZV",
+    vendorStateCode: "27",
+    logoPath: "/secret/logo.png",
+    signaturePath: "/secret/sig.png",
+    gstRegistration: "regular",
+    signatoryName: "Sample",
+    ...patch,
+  });
+
+const invoice = (patch: Partial<Invoice> = {}): Invoice => ({
+  id: 1,
+  number: "INV/2026-001",
+  seriesId: 1,
+  invoiceDate: "2026-04-01",
+  dueDate: "2026-05-01",
+  clientId: 5,
+  clientName: "Client Ltd",
+  clientAddress: "12 MG Road\nBengaluru 560001",
+  clientGstin: "29AABCU9603R1ZJ",
+  poNumber: "PO-9",
+  placeOfSupplyStateCode: "29",
+  subtotal: 7310.1,
+  discount: 10.1,
+  taxType: "igst",
+  taxRate: 18,
+  cgstAmount: 0,
+  sgstAmount: 0,
+  igstAmount: 1314,
+  total: 8614,
+  amountInWords: "Rupees Eight Thousand Six Hundred Fourteen Only",
+  bankAccountId: null,
+  bankSnapshot: "",
+  signaturePath: null,
+  notes: "Thank you",
+  status: "issued",
+  createdAt: "2026-04-01T00:00:00Z",
+  updatedAt: "2026-04-01T00:00:00Z",
+  docType: "tax_invoice",
+  reverseCharge: false,
+  vendorSnapshot: VENDOR(),
+  snapshotOrigin: "issued",
+  cancelledAt: null,
+  cancelReason: "",
+  archivedPdfSha256: null,
+  renderPrefs: "",
+  items: [
+    { id: 1, description: "Design", mode: "fixed", rate: 0, unit: "unit", quantity: 1, amount: 5000.1, sortOrder: 0, hsnSac: "998391" },
+    { id: 2, description: "Consulting", mode: "rate", rate: 1155.05, unit: "hour", quantity: 2, amount: 2310, sortOrder: 1, hsnSac: "" },
+  ],
+  totalPaise: 861400,
+  ...patch,
+});
+
+const client: Client = {
+  ...blankClient(),
+  id: 5,
+  name: "Client Ltd",
+  stateCode: "29",
+  addressLine1: "12 MG Road",
+  addressLine2: "",
+  city: "Bengaluru",
+  pincode: "560001",
+  gstCategory: "registered_regular",
+};
+
+const payment = (patch: Partial<Payment> = {}): Payment => ({
+  id: 1,
+  invoiceId: 1,
+  paidOn: "2026-04-10",
+  amountPaise: 700000,
+  tdsPaise: 70000,
+  mode: "bank_transfer",
+  reference: "UTR123",
+  notes: "n",
+  createdAt: "x",
+  ...patch,
+});
+
+describe("voiced.invoice.v1 document", () => {
+  it("matches the golden file for a fixture invoice", () => {
+    const text = toInvoiceJson([buildInvoiceDoc(invoice(), [payment()], client)]);
+    const path = new URL("./__golden__/invoice-v1.golden.json", import.meta.url);
+    if (!existsSync(path)) writeFileSync(path, text);
+    expect(text).toBe(readFileSync(path, "utf8"));
+  });
+
+  it("is deterministic and keeps the key order", () => {
+    const a = toInvoiceJson([buildInvoiceDoc(invoice(), [payment()], client)]);
+    const b = toInvoiceJson([buildInvoiceDoc(invoice(), [payment()], client)]);
+    expect(a).toBe(b);
+    const doc = buildInvoiceDoc(invoice(), [], null);
+    expect(Object.keys(doc).slice(0, 4)).toEqual(["schema", "number", "issue_date", "due_date"]);
+    expect(doc.schema).toBe("voiced.invoice.v1");
+  });
+
+  it("carries every amount as exact paise and a matching decimal string", () => {
+    const doc = buildInvoiceDoc(invoice(), [payment()], client);
+    // Plain float multiplication is off (0.29 * 100 is 28.999999999999996); the paise must be exact integers.
+    expect(0.29 * 100).not.toBe(29);
+    expect(doc.totals.subtotal_paise).toBe(731010);
+    expect(doc.totals.subtotal).toBe("7310.10");
+    expect(doc.totals.discount).toBe("10.10");
+    expect(doc.totals.taxable_value_paise).toBe(730000);
+    expect(doc.totals.tax).toBe("1314.00");
+    expect(doc.totals.total_paise).toBe(861400);
+    expect(doc.totals.total).toBe("8614.00");
+    expect(doc.items[0]).toMatchObject({ quantity: "1", unit: null, rate: "5000.10", taxable_value_paise: 500010, hsn_sac: "998391" });
+    expect(doc.items[1]).toMatchObject({ quantity: "2", unit: "hour", rate: "1155.05", rate_paise: 115505, hsn_sac: null });
+    expect(doc.payments[0]).toMatchObject({ amount: "7000.00", tds: "700.00", tds_paise: 70000 });
+    // Every *_paise field is a safe integer and agrees with its decimal.
+    const walk = (o: unknown, path: string[] = []) => {
+      if (!o || typeof o !== "object") return;
+      const rec = o as Record<string, unknown>;
+      for (const [k, v] of Object.entries(rec)) {
+        if (k.endsWith("_paise")) {
+          expect(Number.isSafeInteger(v), path.concat(k).join(".")).toBe(true);
+          const dec = rec[k.slice(0, -6)];
+          expect(dec, path.concat(k).join(".")).toBe(`${Math.trunc((v as number) / 100)}.${String(Math.abs(v as number) % 100).padStart(2, "0")}`);
+        } else walk(v, path.concat(k));
+      }
+    };
+    walk(JSON.parse(toInvoiceJson([doc])));
+  });
+
+  it("reports the tax heads: CGST+SGST at half rate, IGST whole, none for an unregistered vendor", () => {
+    const intra = buildInvoiceDoc(invoice({ taxType: "cgst_sgst", taxRate: 12.5, cgstAmount: 100.25, sgstAmount: 100.25, igstAmount: 0 }), [], client);
+    expect(intra.tax.cgst).toEqual({ rate: "6.25", amount_paise: 10025, amount: "100.25" });
+    expect(intra.tax.sgst).toEqual({ rate: "6.25", amount_paise: 10025, amount: "100.25" });
+    expect(intra.tax.igst).toEqual({ rate: "0", amount_paise: 0, amount: "0.00" });
+    expect(intra.tax.utgst.amount_paise).toBe(0);
+    expect(intra.totals.tax_paise).toBe(20050);
+
+    const inter = buildInvoiceDoc(invoice(), [], client);
+    expect(inter.tax.igst).toEqual({ rate: "18", amount_paise: 131400, amount: "1314.00" });
+    expect(inter.tax.cgst.rate).toBe("0");
+  });
+
+  it("moves the second head to UTGST when the supplier is in a union territory", () => {
+    const doc = buildInvoiceDoc(
+      invoice({ taxType: "cgst_sgst", taxRate: 18, cgstAmount: 90, sgstAmount: 90, igstAmount: 0, vendorSnapshot: VENDOR({ vendorStateCode: "04" }) }),
+      [],
+      client,
+    );
+    expect(doc.tax.sgst.amount_paise).toBe(0);
+    expect(doc.tax.utgst).toEqual({ rate: "9", amount_paise: 9000, amount: "90.00" });
+    expect(doc.supplier.state).toEqual({ code: "04", name: "Chandigarh" });
+  });
+
+  it("flags a cancelled invoice and keeps its figures", () => {
+    const doc = buildInvoiceDoc(invoice({ status: "cancelled", cancelledAt: "2026-04-05T10:00:00Z", cancelReason: "wrong client" }), [], client);
+    expect(doc).toMatchObject({ status: "cancelled", cancelled: true, cancelled_at: "2026-04-05T10:00:00Z", cancel_reason: "wrong client" });
+    expect(doc.totals.total).toBe("8614.00");
+    const live = buildInvoiceDoc(invoice(), [], client);
+    expect(live).toMatchObject({ cancelled: false, cancelled_at: null, cancel_reason: null });
+  });
+
+  it("exports an unregistered vendor's plain invoice without tax or GSTIN", () => {
+    const doc = buildInvoiceDoc(
+      invoice({
+        docType: "invoice",
+        taxType: "none",
+        taxRate: 0,
+        igstAmount: 0,
+        subtotal: 7300,
+        discount: 0,
+        total: 7300,
+        totalPaise: 730000,
+        clientGstin: "",
+        vendorSnapshot: VENDOR({ gstRegistration: "unregistered", vendorGstin: "" }),
+      }),
+      [],
+      null,
+    );
+    expect(doc.document_type).toBe("invoice");
+    expect(doc.supplier).toMatchObject({ gstin: null, gst_registration: "unregistered" });
+    expect(doc.totals.tax_paise).toBe(0);
+    expect(doc.tax.igst.rate).toBe("0");
+    expect(doc.client.gstin).toBeNull();
+    expect(doc.client.gst_category).toBe("unregistered");
+    expect(doc.client.address).toMatchObject({ line1: null, city: null, state: null });
+  });
+
+  it("does not leak local file paths from the supplier snapshot", () => {
+    const text = toInvoiceJson([buildInvoiceDoc(invoice(), [], client)]);
+    expect(text).not.toContain("/secret/");
+    expect(text).not.toContain("a@example.com");
+  });
+
+  it("survives a missing or broken supplier snapshot", () => {
+    for (const vendorSnapshot of ["", "not json", "null"]) {
+      const doc = buildInvoiceDoc(invoice({ vendorSnapshot }), [], client);
+      expect(doc.supplier).toMatchObject({ name: "", gstin: null, state: { code: "", name: "" } });
+    }
+  });
+
+  it("converts rupees and rates without noise", () => {
+    expect(rupeesToPaise(0.29)).toBe(29);
+    expect(rupeesToPaise(-0.001)).toBe(0);
+    expect(() => rupeesToPaise(Number.NaN)).toThrow();
+    expect(rateString(9)).toBe("9");
+    expect(rateString(2.5)).toBe("2.5");
+    expect(rateString(0.1 + 0.2)).toBe("0.3");
+  });
+});
+
+describe("line-items CSV", () => {
+  it("writes a BOM, CRLF, a header and one row per line with invoice amounts on the first row only", () => {
+    const csv = toLineItemsCsv([buildInvoiceDoc(invoice(), [], client)]);
+    expect(csv.startsWith("")).toBe(true);
+    const lines = csv.slice(1).split("\r\n");
+    expect(lines[0]).toBe(LINE_CSV_HEADERS.join(","));
+    expect(lines).toHaveLength(4); // header, 2 lines, trailing empty
+    const first = lines[1].split(",");
+    const second = lines[2].split(",");
+    const col = (name: string) => LINE_CSV_HEADERS.indexOf(name);
+    expect(first[col("invoice_total")]).toBe("8614.00");
+    expect(second[col("invoice_total")]).toBe("");
+    expect(first[col("invoice_igst")]).toBe("1314.00");
+    expect(second[col("taxable_value")]).toBe("2310.00");
+    expect(first[col("invoice_number")]).toBe("INV/2026-001");
+  });
+
+  it("quotes commas and quotes, and guards formulas", () => {
+    const doc = buildInvoiceDoc(invoice({ items: [{ id: 1, description: '=SUM(A1), "x"', mode: "fixed", rate: 0, unit: "unit", quantity: 1, amount: 10, sortOrder: 0 }] }), [], client);
+    const csv = toLineItemsCsv([doc]);
+    expect(csv).toContain(`"'=SUM(A1), ""x"""`);
+  });
+
+  it("keeps an invoice with no items as one row", () => {
+    const csv = toLineItemsCsv([buildInvoiceDoc(invoice({ items: [] }), [], client)]);
+    expect(csv.slice(1).split("\r\n")).toHaveLength(3);
+  });
+});
+
+describe("saving", () => {
+  const deps = (over: Partial<InvoiceExportDeps> = {}): InvoiceExportDeps & { written: { path: string; text: string }[] } => {
+    const written: { path: string; text: string }[] = [];
+    return {
+      written,
+      getInvoice: async (id) => invoice({ id, number: `INV/2026-00${id}` }),
+      listPayments: async () => [payment()],
+      listClients: async () => [client],
+      getLastExportDir: async () => "/home/a/exports",
+      save: async ({ defaultPath }) => defaultPath,
+      writeExportFile: async (path, bytes) => {
+        written.push({ path, text: new TextDecoder().decode(bytes) });
+        return path;
+      },
+      now: () => new Date("2026-06-01T10:00:00Z"),
+      ...over,
+    };
+  };
+
+  it("names the file after the invoice or the count", () => {
+    const one = [buildInvoiceDoc(invoice(), [], null)];
+    const now = new Date("2026-06-01T10:00:00Z");
+    expect(invoiceExportName(one, "json", now)).toBe("voiced-invoice-INV-2026-001.json");
+    expect(invoiceExportName(one, "csv", now)).toBe("voiced-invoice-INV-2026-001-lines.csv");
+    expect(invoiceExportName([...one, ...one], "json", now)).toBe("voiced-invoices-2-2026-06-01.json");
+  });
+
+  it("writes the chosen invoices in order, once each", async () => {
+    const d = deps();
+    const done = await exportInvoicesV1(d, [2, 1, 2], "json");
+    expect(done).toEqual({ path: "/home/a/exports/voiced-invoices-2-2026-06-01.json", count: 2 });
+    const docs = JSON.parse(d.written[0].text) as { number: string }[];
+    expect(docs.map((x) => x.number)).toEqual(["INV/2026-002", "INV/2026-001"]);
+  });
+
+  it("returns null when the dialog is cancelled and writes nothing", async () => {
+    const d = deps({ save: async () => null });
+    expect(await exportInvoicesV1(d, [1], "csv")).toBeNull();
+    expect(d.written).toHaveLength(0);
+  });
+
+  it("still exports when the client list cannot be read", async () => {
+    const docs = await loadInvoiceDocs(deps({ listClients: async () => Promise.reject(new Error("db")) }), [1]);
+    expect(docs).toHaveLength(1);
+    expect(docs[0].client.address.line1).toBeNull();
+  });
+
+  it("works without a remembered folder", async () => {
+    const d = deps({ getLastExportDir: async () => Promise.reject(new Error("none")) });
+    const done = await exportInvoicesV1(d, [1], "json");
+    expect(done?.path).toBe("voiced-invoice-INV-2026-001.json");
+  });
+});

src/lib/invoiceExportV1.ts

@@ -0,0 +1,364 @@
+/**
+ * The generic `voiced.invoice.v1` export: a canonical, deterministic JSON document per invoice (and a CSV of line
+ * items) for software that Voiced has no direct integration with. Pure: it formats data it is handed, using integer
+ * paise for every amount, and never touches Tauri. The format is described in docs/voiced-invoice-v1.md.
+ */
+import { csvField, guardFormula, joinPath, paiseToDecimal } from "./historyExport";
+import type { Payment } from "./payments";
+import { INDIAN_STATES, type Client, type Invoice } from "./types";
+
+export const INVOICE_SCHEMA = "voiced.invoice.v1";
+
+/** Union territories without a legislature (mirror of `is_ut_without_legislature` in gst.rs): their second head is UTGST. */
+const UT_WITHOUT_LEGISLATURE = new Set(["04", "26", "31", "35", "38"]);
+
+export interface TaxHeadV1 {
+  /** Percent, e.g. "9" or "2.5"; "0" when the head does not apply to the invoice. */
+  rate: string;
+  amount_paise: number;
+  amount: string;
+}
+
+export interface InvoiceDocV1 {
+  schema: typeof INVOICE_SCHEMA;
+  number: string;
+  issue_date: string;
+  due_date: string | null;
+  document_type: "tax_invoice" | "invoice";
+  status: string;
+  cancelled: boolean;
+  cancelled_at: string | null;
+  cancel_reason: string | null;
+  currency: "INR";
+  po_number: string | null;
+  supplier: {
+    name: string;
+    address: string;
+    gstin: string | null;
+    pan: string | null;
+    gst_registration: string;
+    state: { code: string; name: string };
+  };
+  client: {
+    name: string;
+    gstin: string | null;
+    gst_category: string;
+    address: {
+      text: string;
+      line1: string | null;
+      line2: string | null;
+      city: string | null;
+      pincode: string | null;
+      state: { code: string; name: string } | null;
+    };
+    place_of_supply: { code: string; name: string };
+  };
+  items: {
+    line: number;
+    description: string;
+    hsn_sac: string | null;
+    quantity: string;
+    unit: string | null;
+    rate_paise: number;
+    rate: string;
+    taxable_value_paise: number;
+    taxable_value: string;
+  }[];
+  tax: { cgst: TaxHeadV1; sgst: TaxHeadV1; utgst: TaxHeadV1; igst: TaxHeadV1 };
+  totals: {
+    subtotal_paise: number;
+    subtotal: string;
+    discount_paise: number;
+    discount: string;
+    taxable_value_paise: number;
+    taxable_value: string;
+    tax_paise: number;
+    tax: string;
+    total_paise: number;
+    total: string;
+    amount_in_words: string | null;
+  };
+  reverse_charge: boolean;
+  notes: string | null;
+  payments: {
+    date: string;
+    amount_paise: number;
+    amount: string;
+    tds_paise: number;
+    tds: string;
+    mode: string;
+    reference: string | null;
+  }[];
+}
+
+/** Rupees as stored (a REAL with two decimals) to integer paise, rounded exactly as the backend does. */
+export function rupeesToPaise(rupees: number): number {
+  const paise = Math.round(rupees * 100);
+  if (!Number.isSafeInteger(paise)) throw new Error(`Not an amount: ${rupees}`);
+  return paise === 0 ? 0 : paise; // no negative zero
+}
+
+const blank = (s: string | null | undefined): string | null => {
+  const t = (s ?? "").trim();
+  return t === "" ? null : t;
+};
+
+const gstinOf = (s: string | null | undefined): string | null => {
+  const t = blank(s);
+  return t === null || t.toUpperCase() === "NA" ? null : t;
+};
+
+const stateOf = (code: string): { code: string; name: string } => ({
+  code,
+  name: INDIAN_STATES.find((s) => s.code === code)?.name ?? "",
+});
+
+/** A percentage as the shortest decimal string (9, 6.25), without binary noise. */
+export function rateString(rate: number): string {
+  return String(Number(rate.toFixed(4)));
+}
+
+interface Snapshot {
+  vendorName?: string;
+  vendorAddress?: string;
+  vendorGstin?: string;
+  vendorPan?: string;
+  vendorStateCode?: string;
+  gstRegistration?: string;
+}
+
+function parseSnapshot(text: string): Snapshot {
+  try {
+    const v: unknown = text ? JSON.parse(text) : {};
+    return v && typeof v === "object" ? (v as Snapshot) : {};
+  } catch {
+    return {};
+  }
+}
+
+const head = (rate: number, rupees: number): TaxHeadV1 => {
+  const paise = rupeesToPaise(rupees);
+  return { rate: rateString(rate), amount_paise: paise, amount: paiseToDecimal(paise) };
+};
+
+/**
+ * One invoice as `voiced.invoice.v1`. The supplier comes from the snapshot frozen at issue. The client's name, GSTIN
+ * and place of supply are frozen on the invoice too; the structured address and GST category are read from the saved
+ * client record (`client`, optional) because the invoice only froze the printed text.
+ */
+export function buildInvoiceDoc(invoice: Invoice, payments: Payment[], client?: Client | null): InvoiceDocV1 {
+  const snap = parseSnapshot(invoice.vendorSnapshot);
+  const supplierState = snap.vendorStateCode ?? "";
+  const isUt = UT_WITHOUT_LEGISLATURE.has(supplierState);
+  const half = invoice.taxType === "cgst_sgst" ? invoice.taxRate / 2 : 0;
+  const igstRate = invoice.taxType === "igst" ? invoice.taxRate : 0;
+
+  const zero = (): TaxHeadV1 => head(0, 0);
+  const secondHead = head(half, invoice.sgstAmount);
+  const tax = {
+    cgst: head(half, invoice.cgstAmount),
+    sgst: isUt ? zero() : secondHead,
+    utgst: isUt ? secondHead : zero(),
+    igst: head(igstRate, invoice.igstAmount),
+  };
+
+  const subtotal = rupeesToPaise(invoice.subtotal);
+  const discount = rupeesToPaise(invoice.discount);
+  const totalTax = tax.cgst.amount_paise + tax.sgst.amount_paise + tax.utgst.amount_paise + tax.igst.amount_paise;
+  const total = invoice.totalPaise ?? rupeesToPaise(invoice.total);
+
+  const gstin = gstinOf(invoice.clientGstin);
+  const pos = invoice.placeOfSupplyStateCode;
+  const clientState = client && client.stateCode ? stateOf(client.stateCode) : null;
+
+  return {
+    schema: INVOICE_SCHEMA,
+    number: invoice.number,
+    issue_date: invoice.invoiceDate,
+    due_date: blank(invoice.dueDate),
+    document_type: invoice.docType,
+    status: invoice.status,
+    cancelled: invoice.status === "cancelled",
+    cancelled_at: invoice.status === "cancelled" ? blank(invoice.cancelledAt) : null,
+    cancel_reason: invoice.status === "cancelled" ? blank(invoice.cancelReason) : null,
+    currency: "INR",
+    po_number: blank(invoice.poNumber),
+    supplier: {
+      name: snap.vendorName ?? "",
+      address: snap.vendorAddress ?? "",
+      gstin: gstinOf(snap.vendorGstin),
+      pan: blank(snap.vendorPan),
+      gst_registration: snap.gstRegistration ?? "",
+      state: stateOf(supplierState),
+    },
+    client: {
+      name: invoice.clientName,
+      gstin,
+      gst_category: client?.gstCategory ?? (gstin ? "registered_regular" : "unregistered"),
+      address: {
+        text: invoice.clientAddress,
+        line1: blank(client?.addressLine1),
+        line2: blank(client?.addressLine2),
+        city: blank(client?.city),
+        pincode: blank(client?.pincode),
+        state: clientState,
+      },
+      place_of_supply: stateOf(pos),
+    },
+    items: invoice.items.map((item, index) => {
+      const fixed = item.mode === "fixed";
+      const amount = rupeesToPaise(item.amount);
+      const rate = fixed ? amount : rupeesToPaise(item.rate);
+      return {
+        line: index + 1,
+        description: item.description,
+        hsn_sac: blank(item.hsnSac),
+        quantity: fixed ? "1" : String(item.quantity),
+        unit: fixed ? null : item.unit,
+        rate_paise: rate,
+        rate: paiseToDecimal(rate),
+        taxable_value_paise: amount,
+        taxable_value: paiseToDecimal(amount),
+      };
+    }),
+    tax,
+    totals: {
+      subtotal_paise: subtotal,
+      subtotal: paiseToDecimal(subtotal),
+      discount_paise: discount,
+      discount: paiseToDecimal(discount),
+      taxable_value_paise: subtotal - discount,
+      taxable_value: paiseToDecimal(subtotal - discount),
+      tax_paise: totalTax,
+      tax: paiseToDecimal(totalTax),
+      total_paise: total,
+      total: paiseToDecimal(total),
+      amount_in_words: blank(invoice.amountInWords),
+    },
+    reverse_charge: invoice.reverseCharge,
+    notes: blank(invoice.notes),
+    payments: payments.map((p) => ({
+      date: p.paidOn,
+      amount_paise: p.amountPaise,
+      amount: paiseToDecimal(p.amountPaise),
+      tds_paise: p.tdsPaise,
+      tds: paiseToDecimal(p.tdsPaise),
+      mode: p.mode,
+      reference: blank(p.reference),
+    })),
+  };
+}
+
+/** The JSON file: an array of invoice documents in the given order. Same input, same bytes. */
+export function toInvoiceJson(docs: InvoiceDocV1[]): string {
+  return `${JSON.stringify(docs, null, 2)}\n`;
+}
+
+// ---- CSV: one row per line item ----
+
+type Kind = "text" | "amount";
+
+const LINE_COLUMNS: readonly { header: string; kind: Kind; value: (d: InvoiceDocV1, line: number) => string }[] = [
+  { header: "invoice_number", kind: "text", value: (d) => d.number },
+  { header: "issue_date", kind: "text", value: (d) => d.issue_date },
+  { header: "due_date", kind: "text", value: (d) => d.due_date ?? "" },
+  { header: "document_type", kind: "text", value: (d) => d.document_type },
+  { header: "status", kind: "text", value: (d) => d.status },
+  { header: "cancelled", kind: "text", value: (d) => (d.cancelled ? "yes" : "no") },
+  { header: "currency", kind: "text", value: (d) => d.currency },
+  { header: "supplier_name", kind: "text", value: (d) => d.supplier.name },
+  { header: "supplier_gstin", kind: "text", value: (d) => d.supplier.gstin ?? "" },
+  { header: "client_name", kind: "text", value: (d) => d.client.name },
+  { header: "client_gstin", kind: "text", value: (d) => d.client.gstin ?? "" },
+  { header: "client_gst_category", kind: "text", value: (d) => d.client.gst_category },
+  { header: "place_of_supply_code", kind: "text", value: (d) => d.client.place_of_supply.code },
+  { header: "place_of_supply", kind: "text", value: (d) => d.client.place_of_supply.name },
+  { header: "reverse_charge", kind: "text", value: (d) => (d.reverse_charge ? "yes" : "no") },
+  { header: "line", kind: "text", value: (d, i) => (d.items[i] ? String(d.items[i].line) : "") },
+  { header: "description", kind: "text", value: (d, i) => d.items[i]?.description ?? "" },
+  { header: "hsn_sac", kind: "text", value: (d, i) => d.items[i]?.hsn_sac ?? "" },
+  { header: "quantity", kind: "text", value: (d, i) => d.items[i]?.quantity ?? "" },
+  { header: "unit", kind: "text", value: (d, i) => d.items[i]?.unit ?? "" },
+  { header: "rate", kind: "amount", value: (d, i) => d.items[i]?.rate ?? "" },
+  { header: "taxable_value", kind: "amount", value: (d, i) => d.items[i]?.taxable_value ?? "" },
+  // Invoice-level amounts sit on the first row only, so summing a column never counts an invoice twice.
+  { header: "invoice_discount", kind: "amount", value: (d, i) => (i === 0 ? d.totals.discount : "") },
+  { header: "invoice_cgst", kind: "amount", value: (d, i) => (i === 0 ? d.tax.cgst.amount : "") },
+  { header: "invoice_sgst", kind: "amount", value: (d, i) => (i === 0 ? d.tax.sgst.amount : "") },
+  { header: "invoice_utgst", kind: "amount", value: (d, i) => (i === 0 ? d.tax.utgst.amount : "") },
+  { header: "invoice_igst", kind: "amount", value: (d, i) => (i === 0 ? d.tax.igst.amount : "") },
+  { header: "invoice_total", kind: "amount", value: (d, i) => (i === 0 ? d.totals.total : "") },
+];
+
+export const LINE_CSV_HEADERS: readonly string[] = LINE_COLUMNS.map((c) => c.header);
+
+/** UTF-8 BOM, CRLF, header row always present; text cells are guarded against spreadsheet formulas. */
+export function toLineItemsCsv(docs: InvoiceDocV1[]): string {
+  const lines: string[] = [LINE_COLUMNS.map((c) => csvField(c.header)).join(",")];
+  for (const doc of docs) {
+    const rows = Math.max(1, doc.items.length);
+    for (let i = 0; i < rows; i++) {
+      lines.push(LINE_COLUMNS.map((c) => csvField(c.kind === "text" ? guardFormula(c.value(doc, i)) : c.value(doc, i))).join(","));
+    }
+  }
+  return `${lines.join("\r\n")}\r\n`;
+}
+
+// ---- saving ----
+
+export type InvoiceExportFormat = "json" | "csv";
+
+const safeName = (s: string) => s.replace(/[^A-Za-z0-9._-]+/g, "-");
+
+export function invoiceExportName(docs: InvoiceDocV1[], format: InvoiceExportFormat, now: Date): string {
+  const base =
+    docs.length === 1
+      ? `voiced-invoice-${safeName(docs[0].number)}`
+      : `voiced-invoices-${docs.length}-${now.toISOString().slice(0, 10)}`;
+  return `${base}${format === "csv" ? "-lines" : ""}.${format}`;
+}
+
+export interface InvoiceExportDeps {
+  getInvoice(id: number): Promise<Invoice>;
+  listPayments(invoiceId: number): Promise<Payment[]>;
+  listClients(): Promise<Client[]>;
+  getLastExportDir(): Promise<string>;
+  save(opts: { defaultPath: string; format: InvoiceExportFormat }): Promise<string | null>;
+  writeExportFile(path: string, bytes: Uint8Array): Promise<string>;
+  now(): Date;
+}
+
+/** Reads the invoices (frozen data plus payments) in the order given; the client record is optional detail. */
+export async function loadInvoiceDocs(deps: Pick<InvoiceExportDeps, "getInvoice" | "listPayments" | "listClients">, ids: number[]): Promise<InvoiceDocV1[]> {
+  const unique = [...new Set(ids)];
+  const loaded: { invoice: Invoice; payments: Payment[] }[] = [];
+  for (const id of unique) {
+    const [invoice, payments] = await Promise.all([deps.getInvoice(id), deps.listPayments(id)]);
+    loaded.push({ invoice, payments });
+  }
+  let clients = new Map<number, Client>();
+  if (loaded.some((l) => l.invoice.clientId !== null)) {
+    try {
+      clients = new Map((await deps.listClients()).filter((c) => c.id !== null).map((c) => [c.id as number, c]));
+    } catch {
+      // The structured address is extra detail; the export is complete without it.
+    }
+  }
+  return loaded.map(({ invoice, payments }) => buildInvoiceDoc(invoice, payments, invoice.clientId === null ? null : (clients.get(invoice.clientId) ?? null)));
+}
+
+/** Exports the chosen invoices through the save dialog. Returns the path, or null if the dialog was cancelled. */
+export async function exportInvoicesV1(deps: InvoiceExportDeps, ids: number[], format: InvoiceExportFormat): Promise<{ path: string; count: number } | null> {
+  const docs = await loadInvoiceDocs(deps, ids);
+  const text = format === "csv" ? toLineItemsCsv(docs) : toInvoiceJson(docs);
+  let dir = "";
+  try {
+    dir = await deps.getLastExportDir();
+  } catch {
+    // No remembered folder: the dialog opens wherever the system prefers.
+  }
+  const chosen = await deps.save({ defaultPath: joinPath(dir, invoiceExportName(docs, format, deps.now())), format });
+  if (!chosen) return null;
+  const path = (await deps.writeExportFile(chosen, new TextEncoder().encode(text))) || chosen;
+  return { path, count: docs.length };
+}

src/lib/payments.ts

@@ -23,9 +23,11 @@ export interface Payment {
   reference: string;
   notes: string;
   createdAt: string;
+  /** Payment Entry name on ERPNext once the payment was sent. */
+  erpnextPaymentEntry?: string | null;
 }
 
-export type PaymentInput = Omit<Payment, "id" | "createdAt">;
+export type PaymentInput = Omit<Payment, "id" | "createdAt" | "erpnextPaymentEntry">;
 
 type TagType = "red" | "green" | "blue" | "gray" | "warm-gray" | "cool-gray" | "purple";
 

src/lib/settingsTab.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { SETTINGS_TABS, loadSettingsTab, parseSettingsTab, saveSettingsTab } from "./settingsTab";
+import { SETTINGS_TABS, loadSettingsTab, parseSettingsTab, requestSettingsTab, saveSettingsTab } from "./settingsTab";
 
 describe("settings tab persistence", () => {
   it("maps stored ids to indexes and falls back to the first tab", () => {
@@ -14,4 +14,10 @@ describe("settings tab persistence", () => {
     expect(() => saveSettingsTab(2)).not.toThrow();
     expect(() => saveSettingsTab(99)).not.toThrow();
   });
+
+  it("honours a requested tab once, then goes back to the stored one", () => {
+    requestSettingsTab("integrations");
+    expect(loadSettingsTab()).toBe(SETTINGS_TABS.findIndex((t) => t.id === "integrations"));
+    expect(loadSettingsTab()).toBe(0);
+  });
 });

src/lib/settingsTab.ts

@@ -9,6 +9,7 @@ export const SETTINGS_TABS = [
   { id: "templates", label: "Templates & export" },
   { id: "fonts", label: "Fonts" },
   { id: "data", label: "Data" },
+  { id: "integrations", label: "Integrations" },
 ] as const;
 
 export type SettingsTabId = (typeof SETTINGS_TABS)[number]["id"];
@@ -19,8 +20,21 @@ export function parseSettingsTab(value: string | null | undefined): number {
   return index < 0 ? 0 : index;
 }
 
+/** A tab another screen asked for; used once by the next Settings mount, so it works without localStorage. */
+let requested: SettingsTabId | null = null;
+
+/** Makes the next opening of Settings land on `id` (for "Set up in Settings" links). */
+export function requestSettingsTab(id: SettingsTabId): void {
+  requested = id;
+}
+
 /** The last Settings tab this viewer used. A per-viewer convenience only. */
 export function loadSettingsTab(): number {
+  if (requested) {
+    const index = parseSettingsTab(requested);
+    requested = null;
+    return index;
+  }
   try {
     return parseSettingsTab(localStorage.getItem(KEY));
   } catch {

src/styles/carbon.scss

@@ -698,3 +698,76 @@ body {
 .voiced-detail__unarchived p {
   margin-bottom: 1rem;
 }
+
+/* Settings, Integrations, ERPNext */
+.voiced-erp__section > h3 {
+  margin-bottom: 0.5rem;
+}
+
+.voiced-erp__fields {
+  display: grid;
+  gap: 1rem;
+  max-width: 40rem;
+  margin-top: 1rem;
+}
+
+.voiced-erp__label {
+  font-size: 0.75rem;
+  color: var(--cds-text-secondary);
+  margin-bottom: 0.25rem;
+}
+
+.voiced-erp__secret > * + * {
+  margin-top: 0.5rem;
+}
+
+.voiced-erp__result > * + * {
+  margin-top: 0.75rem;
+}
+
+.voiced-erp__uoms {
+  border: 0;
+  padding: 0;
+  display: grid;
+  gap: 1rem;
+}
+
+.voiced-erp__uoms legend {
+  font-size: 0.75rem;
+  color: var(--cds-text-secondary);
+}
+
+.voiced-erp__error {
+  color: var(--cds-text-error);
+  font-size: 0.75rem;
+}
+
+/* ERPNext column and bulk-send bar on the invoices list */
+.voiced-history__bulk {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 0.5rem;
+  margin-bottom: 1rem;
+}
+
+.voiced-erp__results {
+  list-style: none;
+  margin-top: 1rem;
+  max-height: 16rem;
+  overflow: auto;
+}
+
+.voiced-erp__results li {
+  padding: 0.25rem 0;
+  border-bottom: 1px solid var(--cds-border-subtle);
+}
+
+.voiced-erp__panel {
+  border: 1px solid var(--cds-border-subtle);
+  padding: 1rem;
+}
+
+.voiced-erp__panel > * + * {
+  margin-top: 0.75rem;
+}

src/views/AppSettings.tsx

@@ -41,6 +41,7 @@ import { ImagePicker } from "../components/ImagePicker";
 import { LogoBranding } from "../components/LogoBranding";
 import DataBackupPanel from "../components/DataBackupPanel";
 import DiagnosticsPanel from "../components/DiagnosticsPanel";
+import ErpnextSettingsPanel from "../components/ErpnextSettingsPanel";
 import { FontOverrideTable } from "../components/FontOverrideTable";
 import { useToast } from "../components/ToastProvider";
 import { SETTINGS_TABS, loadSettingsTab, saveSettingsTab } from "../lib/settingsTab";
@@ -159,7 +160,7 @@ export default function AppSettings({
   return (
     <div className="voiced-page">
       <h1 className="voiced-page__title">Settings</h1>
-      <p className="voiced-page__subtitle">Business details, branding, defaults and bank accounts.</p>
+      <p className="voiced-page__subtitle">Business details, branding, defaults, bank accounts and integrations.</p>
 
       <Tabs selectedIndex={tab} onChange={({ selectedIndex }) => selectTab(selectedIndex)}>
         <TabList aria-label="Settings sections" contained scrollIntoView>
@@ -171,6 +172,7 @@ export default function AppSettings({
           <Tab>Templates &amp; export</Tab>
           <Tab>Fonts</Tab>
           <Tab>Data</Tab>
+          <Tab>Integrations</Tab>
         </TabList>
         <TabPanels>
             <TabPanel>
@@ -516,6 +518,9 @@ export default function AppSettings({
             <TabPanel>
               <DataBackupPanel />
             </TabPanel>
+            <TabPanel>
+              <ErpnextSettingsPanel active={tab === SETTINGS_TABS.findIndex((t) => t.id === "integrations")} />
+            </TabPanel>
         </TabPanels>
       </Tabs>
 

src/views/InvoiceDetail.tsx

@@ -3,6 +3,7 @@ import {
   Button,
   InlineLoading,
   InlineNotification,
+  Link,
   Modal,
   OverflowMenu,
   OverflowMenuItem,
@@ -28,6 +29,20 @@ import { toDraftPayload } from "../lib/draft";
 import { invoiceToFormState } from "../lib/duplicate";
 import type { ExportMode } from "../lib/filename";
 import { useInvoiceExport } from "../hooks/useInvoiceExport";
+import { useGenericExport } from "../hooks/useGenericExport";
+import { openInErpnext } from "../lib/erpnextActions";
+import type { ErpnextConfig, ErpnextPushResult, ErpnextSyncStatus } from "../lib/erpnext";
+import {
+  canOpenInErpnext,
+  describePaymentPush,
+  describePush,
+  failedPush,
+  formatSyncedAt,
+  isConfigured,
+  paymentPushDisabledReason,
+  pushDisabledReason,
+  syncTag,
+} from "../lib/erpnextUi";
 import { useReturnFocus } from "../hooks/useReturnFocus";
 import ExportFeedback from "../components/ExportFeedback";
 import PdfPreview from "../components/PdfPreview";
@@ -41,6 +56,8 @@ interface Props {
   onBack: () => void;
   /** A draft was created from this invoice; the shell opens it in the New invoice form. */
   onDuplicated: (draftId: number) => void;
+  /** Goes to Settings, Integrations. */
+  onOpenSettings: () => void;
 }
 
 interface Frozen {
@@ -74,7 +91,7 @@ function Field({ label, children }: { label: string; children: React.ReactNode }
   );
 }
 
-export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicated }: Props) {
+export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicated, onOpenSettings }: Props) {
   const toast = useToast();
   const [invoice, setInvoice] = useState<Invoice | null>(null);
   const [payments, setPayments] = useState<Payment[]>([]);
@@ -88,6 +105,12 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
   const [cancelOpen, setCancelOpen] = useState(false);
   const [reason, setReason] = useState("");
   const [duplicating, setDuplicating] = useState(false);
+  const [erpCfg, setErpCfg] = useState<ErpnextConfig | null>(null);
+  const [erpSync, setErpSync] = useState<ErpnextSyncStatus | undefined>(undefined);
+  const [lastPush, setLastPush] = useState<ErpnextPushResult | null>(null);
+  const [sendingErp, setSendingErp] = useState(false);
+  const [sendingPayment, setSendingPayment] = useState<number | null>(null);
+  const generic = useGenericExport();
   useReturnFocus(deleteTarget !== null);
   useReturnFocus(cancelOpen);
 
@@ -123,14 +146,31 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
     }
   }, []);
 
+  /** ERPNext is optional: when it cannot be read the panel just stays out of the way. */
+  const loadErp = useCallback(async (id: number, gen: number) => {
+    try {
+      const [cfg, sync] = await Promise.all([api.erpnextGetConfig(), api.erpnextSyncStatus(id)]);
+      if (gen !== generation.current) return;
+      setErpCfg(cfg);
+      setErpSync(sync);
+    } catch {
+      if (gen === generation.current) {
+        setErpCfg(null);
+        setErpSync(undefined);
+      }
+    }
+  }, []);
+
   useEffect(() => {
     const gen = ++generation.current;
     setInvoice(null);
     setPdf(null);
     setArchive(null);
+    setLastPush(null);
     void loadData(invoiceId, gen);
     void loadPdf(invoiceId, gen);
-  }, [invoiceId, loadData, loadPdf]);
+    void loadErp(invoiceId, gen);
+  }, [invoiceId, loadData, loadPdf, loadErp]);
 
   const refresh = () => loadData(invoiceId, generation.current);
 
@@ -194,6 +234,44 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
     }
   };
 
+  /** `submit` undefined keeps what the invoice already is in ERPNext. A failure is shown, never thrown. */
+  const onSendErp = async (submit: boolean) => {
+    if (!invoice) return;
+    setSendingErp(true);
+    let result: ErpnextPushResult;
+    try {
+      result = await api.erpnextPushInvoice(invoice.id, submit);
+    } catch (e) {
+      result = failedPush(invoice.id, invoice.number, e);
+    }
+    setLastPush(result);
+    const note = describePush(result);
+    toast[note.kind](note.title, note.subtitle);
+    await loadErp(invoiceId, generation.current);
+    setSendingErp(false);
+  };
+
+  const onOpenErp = async () => {
+    try {
+      await openInErpnext(invoiceId);
+    } catch (e) {
+      toast.error("Could not open ERPNext", String(e));
+    }
+  };
+
+  const onSendPayment = async (paymentId: number) => {
+    setSendingPayment(paymentId);
+    try {
+      const note = describePaymentPush(await api.erpnextPushPayment(paymentId));
+      toast[note.kind](note.title, note.subtitle);
+      await refresh();
+    } catch (e) {
+      toast.error("Could not send the payment", String(e));
+    } finally {
+      setSendingPayment(null);
+    }
+  };
+
   const onDeletePayment = async () => {
     if (!deleteTarget) return;
     const target = deleteTarget;
@@ -231,6 +309,12 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
   const balance = invoice.balancePaise ?? 0;
   const canPay = invoice.status === "issued" && balance > 0;
   const half = invoice.taxRate / 2;
+  const erpOn = isConfigured(erpCfg);
+  const erpTag = syncTag(erpSync);
+  const erpBlocked = pushDisabledReason({ cfg: erpCfg, vendorRegistered: settings.gstRegistration !== "unregistered", invoiceStatus: invoice.status });
+  const erpHasState = Boolean(erpSync && erpSync.status !== "none");
+  const erpSubmitted = erpSync?.status === "synced" && erpSync.remoteDocstatus === 1;
+  const showPaymentErp = erpOn || payments.some((p) => p.erpnextPaymentEntry);
 
   return (
     <div className="voiced-page voiced-detail">
@@ -284,6 +368,8 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
         </Button>
         <OverflowMenu aria-label="More actions" iconDescription="More actions" flipped size="md" disabled={busy}>
           <OverflowMenuItem itemText="Re-render with current template" onClick={() => onExport("searchable", "rerender")} />
+          <OverflowMenuItem itemText="Export as voiced.invoice.v1 (JSON)" hasDivider onClick={() => void generic.run([invoice.id], "json")} />
+          <OverflowMenuItem itemText="Export line items (CSV)" onClick={() => void generic.run([invoice.id], "csv")} />
           {invoice.status === "issued" ? (
             <OverflowMenuItem
               itemText={payments.length > 0 ? "Cancel invoice (delete payments first)" : "Cancel invoice"}
@@ -416,6 +502,104 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
             {invoice.notes ? <p className="voiced-detail__pre voiced-muted">{invoice.notes}</p> : null}
           </section>
 
+          <section aria-labelledby="detail-erpnext">
+            <h2 id="detail-erpnext" className="voiced-detail__h2">
+              ERPNext
+            </h2>
+            {!erpOn && !erpHasState ? (
+              <p className="voiced-muted">
+                ERPNext is not set up.{" "}
+                <Link
+                  href="#"
+                  onClick={(e: React.MouseEvent) => {
+                    e.preventDefault();
+                    onOpenSettings();
+                  }}
+                >
+                  Set it up in Settings, Integrations
+                </Link>
+                .
+              </p>
+            ) : (
+              <div className="voiced-erp__panel">
+                <dl>
+                  <Field label="Status">
+                    <Tag type={erpTag.type} size="sm" title={erpTag.tooltip}>
+                      {erpTag.label}
+                    </Tag>
+                  </Field>
+                  {erpSync?.remoteName ? <Field label="ERPNext document">{erpSync.remoteName}</Field> : null}
+                  {erpSync?.syncedAt ? <Field label="Last synced">{formatSyncedAt(erpSync.syncedAt)}</Field> : null}
+                  {erpSync?.status === "synced" ? <Field label="PDF">{erpSync.attached ? "Attached in ERPNext" : "Not attached"}</Field> : null}
+                </dl>
+                {erpSync && (erpSync.status === "error" || erpSync.status === "conflict") && erpSync.lastError ? (
+                  <InlineNotification
+                    kind={erpSync.status === "conflict" ? "warning" : "error"}
+                    lowContrast
+                    hideCloseButton
+                    title={erpSync.status === "conflict" ? "Conflict with ERPNext" : "The last send failed"}
+                    subtitle={erpSync.lastError}
+                  />
+                ) : null}
+                {lastPush && lastPush.warnings.length > 0 ? (
+                  <InlineNotification kind="warning" lowContrast hideCloseButton title="Sent with notes" subtitle={lastPush.warnings.join(" ")} />
+                ) : null}
+                {erpOn ? (
+                  <>
+                    <div className="voiced-header-action">
+                      {erpSubmitted ? (
+                        <Button kind="tertiary" size="sm" disabled={sendingErp || erpBlocked !== null} onClick={() => void onSendErp(true)}>
+                          {sendingErp ? "Sending…" : "Re-send"}
+                        </Button>
+                      ) : (
+                        <>
+                          <Button kind="tertiary" size="sm" disabled={sendingErp || erpBlocked !== null} onClick={() => void onSendErp(false)}>
+                            {sendingErp ? "Sending…" : erpHasState ? "Re-send as draft" : "Send as draft"}
+                          </Button>
+                          <Button kind="primary" size="sm" disabled={sendingErp || erpBlocked !== null} onClick={() => void onSendErp(true)}>
+                            Send &amp; submit
+                          </Button>
+                        </>
+                      )}
+                      {canOpenInErpnext(erpSync) ? (
+                        <Button kind="ghost" size="sm" onClick={() => void onOpenErp()}>
+                          Open in ERPNext
+                        </Button>
+                      ) : null}
+                    </div>
+                    {erpBlocked ? (
+                      <p className="voiced-muted">
+                        {erpBlocked}{" "}
+                        <Link
+                          href="#"
+                          onClick={(e: React.MouseEvent) => {
+                            e.preventDefault();
+                            onOpenSettings();
+                          }}
+                        >
+                          Open Settings
+                        </Link>
+                      </p>
+                    ) : null}
+                  </>
+                ) : (
+                  <p className="voiced-muted">
+                    ERPNext is not set up any more, so nothing can be sent.{" "}
+                    <Link
+                      href="#"
+                      onClick={(e: React.MouseEvent) => {
+                        e.preventDefault();
+                        onOpenSettings();
+                      }}
+                    >
+                      Open Settings
+                    </Link>
+                  </p>
+                )}
+              </div>
+            )}
+          </section>
+
           <section aria-labelledby="detail-payments">
             <h2 id="detail-payments" className="voiced-detail__h2">
               Payments
@@ -432,6 +616,7 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
                       <TableHeader>Reference</TableHeader>
                       <TableHeader className="voiced-num">Received</TableHeader>
                       <TableHeader className="voiced-num">TDS</TableHeader>
+                      {showPaymentErp ? <TableHeader>ERPNext</TableHeader> : null}
                       <TableHeader>
                         <span className="cds--assistive-text">Actions</span>
                       </TableHeader>
@@ -448,6 +633,35 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
                         </TableCell>
                         <TableCell className="voiced-num">{formatPaise(p.amountPaise)}</TableCell>
                         <TableCell className="voiced-num">{formatPaise(p.tdsPaise)}</TableCell>
+                        {showPaymentErp ? (
+                          <TableCell>
+                            {p.erpnextPaymentEntry ? (
+                              <>
+                                <Tag type="green" size="sm">
+                                  Sent
+                                </Tag>{" "}
+                                <span className="voiced-muted">{p.erpnextPaymentEntry}</span>
+                              </>
+                            ) : (
+                              (() => {
+                                const reason = paymentPushDisabledReason({ cfg: erpCfg, sync: erpSync, entry: p.erpnextPaymentEntry });
+                                return (
+                                  <>
+                                    <Button
+                                      kind="ghost"
+                                      size="sm"
+                                      disabled={reason !== null || sendingPayment !== null}
+                                      onClick={() => void onSendPayment(p.id)}
+                                    >
+                                      {sendingPayment === p.id ? "Sending…" : "Send payment to ERPNext"}
+                                    </Button>
+                                    {reason ? <div className="voiced-muted">{reason}</div> : null}
+                                  </>
+                                );
+                              })()
+                            )}
+                          </TableCell>
+                        ) : null}
                         <TableCell>
                           <Button
                             kind="ghost"
@@ -507,7 +721,7 @@ export default function InvoiceDetail({ invoiceId, settings, onBack, onDuplicate
       >
         <p>
           {deleteTarget
-            ? `${formatPaise(deleteTarget.amountPaise + deleteTarget.tdsPaise)} (cash ${formatPaise(deleteTarget.amountPaise)}, TDS ${formatPaise(deleteTarget.tdsPaise)}) received on ${formatDate(deleteTarget.paidOn)}. The invoice balance goes back up by that amount.`
+            ? `${formatPaise(deleteTarget.amountPaise + deleteTarget.tdsPaise)} (cash ${formatPaise(deleteTarget.amountPaise)}, TDS ${formatPaise(deleteTarget.tdsPaise)}) received on ${formatDate(deleteTarget.paidOn)}. The invoice balance goes back up by that amount.${deleteTarget.erpnextPaymentEntry ? ` It was sent to ERPNext as ${deleteTarget.erpnextPaymentEntry}; that entry is not removed there.` : ""}`
             : ""}
         </p>
       </Modal>

src/views/InvoiceHistory.tsx

@@ -1,6 +1,7 @@
 import { useEffect, useMemo, useState } from "react";
 import {
   Button,
+  Checkbox,
   InlineLoading,
   Link,
   OverflowMenu,
@@ -43,6 +44,11 @@ import {
 import type { ExportMode } from "../lib/filename";
 import type { ExportSource } from "../lib/exportFlow";
 import { useInvoiceExport } from "../hooks/useInvoiceExport";
+import { useGenericExport } from "../hooks/useGenericExport";
+import { openInErpnext } from "../lib/erpnextActions";
+import type { ErpnextConfig, ErpnextSyncStatus } from "../lib/erpnext";
+import { canOpenInErpnext, indexSyncStatuses, isConfigured, pushDisabledReason, sendableSelection, syncTag } from "../lib/erpnextUi";
+import SendToErpnextModal, { type SendTarget } from "../components/SendToErpnextModal";
 import ExportFeedback from "../components/ExportFeedback";
 import { useToast } from "../components/ToastProvider";
 import type { InvoiceSummary, Settings } from "../lib/types";
@@ -52,6 +58,8 @@ interface Props {
   active: boolean;
   /** Opens the detail page of an invoice. */
   onOpen: (id: number) => void;
+  /** Goes to Settings, Integrations. */
+  onOpenSettings: () => void;
 }
 
 const PAGE_SIZES = [25, 50, 100];
@@ -65,7 +73,7 @@ const COLUMNS: { key: SortKey; label: string; numeric?: boolean }[] = [
   { key: "status", label: "Status" },
 ];
 
-export default function InvoiceHistory({ settings, active, onOpen }: Props) {
+export default function InvoiceHistory({ settings, active, onOpen, onOpenSettings }: Props) {
   const toast = useToast();
   const [rows, setRows] = useState<InvoiceSummary[]>([]);
   const [loading, setLoading] = useState(true);
@@ -76,15 +84,36 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
   const [pageSize, setPageSize] = useState(PAGE_SIZES[0]);
   const exp = useInvoiceExport({ settings, bank: null });
   const [exportingHistory, setExportingHistory] = useState(false);
+  const [erpCfg, setErpCfg] = useState<ErpnextConfig | null>(null);
+  const [syncs, setSyncs] = useState<Map<number, ErpnextSyncStatus>>(new Map());
+  const [selected, setSelected] = useState<Set<number>>(new Set());
+  const [sendTargets, setSendTargets] = useState<{ invoices: SendTarget[]; skipped: number } | null>(null);
+  const generic = useGenericExport();
+
+  /** One bulk call for every row's ERPNext status. ERPNext is optional, so a failure here only hides the column. */
+  const loadErpnext = async () => {
+    try {
+      const [cfg, list] = await Promise.all([api.erpnextGetConfig(), api.erpnextSyncStatuses()]);
+      setErpCfg(cfg);
+      setSyncs(indexSyncStatuses(list));
+    } catch {
+      setErpCfg(null);
+      setSyncs(new Map());
+    }
+  };
 
   const load = async () => {
     try {
-      setRows(await api.listInvoices());
+      const list = await api.listInvoices();
+      setRows(list);
+      // Keep only selections that still exist.
+      setSelected((prev) => new Set([...prev].filter((id) => list.some((r) => r.id === id))));
     } catch (e) {
       toast.error("Could not load invoices", String(e));
     } finally {
       setLoading(false);
     }
+    void loadErpnext();
   };
 
   // The view stays mounted, so refetch every time it is shown again (a payment may have been recorded).
@@ -113,6 +142,44 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
   const onSort = (key: SortKey) =>
     setSort((s) => (s.key === key ? { key, dir: s.dir === "asc" ? "desc" : "asc" } : { key, dir: key === "date" || key === "total" || key === "balance" ? "desc" : "asc" }));
 
+  const erpOn = isConfigured(erpCfg);
+  const vendorRegistered = settings.gstRegistration !== "unregistered";
+  const showErpColumn = erpOn || syncs.size > 0;
+  const selectedRows = rows.filter((r) => selected.has(r.id));
+  const blockedReason = pushDisabledReason({ cfg: erpCfg, vendorRegistered });
+  const pageAllSelected = shown.length > 0 && shown.every((r) => selected.has(r.id));
+  const toggleOne = (id: number, on: boolean) =>
+    setSelected((prev) => {
+      const next = new Set(prev);
+      if (on) next.add(id);
+      else next.delete(id);
+      return next;
+    });
+  const togglePage = (on: boolean) =>
+    setSelected((prev) => {
+      const next = new Set(prev);
+      for (const r of shown) {
+        if (on) next.add(r.id);
+        else next.delete(r.id);
+      }
+      return next;
+    });
+  const askSend = (list: InvoiceSummary[]) => {
+    const { send, skipped } = sendableSelection(list);
+    if (send.length === 0) {
+      toast.warning("Nothing to send", "Only issued invoices are sent to ERPNext.");
+      return;
+    }
+    setSendTargets({ invoices: send.map((r) => ({ id: r.id, number: r.number })), skipped });
+  };
+  const onOpenErpnext = async (id: number) => {
+    try {
+      await openInErpnext(id);
+    } catch (e) {
+      toast.error("Could not open ERPNext", String(e));
+    }
+  };
+
   const onExport = async (id: number, mode: ExportMode, source: ExportSource) => {
     setBusyId(id);
     try {
@@ -259,6 +326,38 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
             </span>
           </div>
 
+          <div className="voiced-history__bulk" role="group" aria-label="Actions for the selected invoices">
+            <span aria-live="polite">{selected.size} selected</span>
+            <Button kind="tertiary" size="md" disabled={selected.size === 0 || blockedReason !== null} onClick={() => askSend(selectedRows)}>
+              Send selected to ERPNext
+            </Button>
+            <Button kind="ghost" size="md" disabled={selected.size === 0 || generic.busy} onClick={() => void generic.run([...selected], "json")}>
+              Export selected (voiced.invoice.v1 JSON)
+            </Button>
+            <Button kind="ghost" size="md" disabled={selected.size === 0 || generic.busy} onClick={() => void generic.run([...selected], "csv")}>
+              Export selected (line items CSV)
+            </Button>
+            {selected.size > 0 ? (
+              <Button kind="ghost" size="md" onClick={() => setSelected(new Set())}>
+                Clear selection
+              </Button>
+            ) : null}
+            {blockedReason !== null && selected.size > 0 ? (
+              <span className="voiced-muted">
+                {blockedReason}{" "}
+                <Link
+                  href="#"
+                  onClick={(e: React.MouseEvent) => {
+                    e.preventDefault();
+                    onOpenSettings();
+                  }}
+                >
+                  Open Settings
+                </Link>
+              </span>
+            ) : null}
+          </div>
+
           {sorted.length === 0 ? (
             <div className="voiced-empty">No invoices match these filters.</div>
           ) : (
@@ -266,6 +365,9 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
               <Table aria-label="Invoices">
                 <TableHead>
                   <TableRow>
+                    <TableHeader>
+                      <Checkbox id="historySelectPage" labelText="Select all invoices on this page" hideLabel checked={pageAllSelected} onChange={(_e, { checked }) => togglePage(checked)} />
+                    </TableHeader>
                     {COLUMNS.map((c) => (
                       <TableHeader
                         key={c.key}
@@ -278,6 +380,7 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
                         {c.label}
                       </TableHeader>
                     ))}
+                    {showErpColumn ? <TableHeader>ERPNext</TableHeader> : null}
                     <TableHeader>
                       <span className="cds--assistive-text">Actions</span>
                     </TableHeader>
@@ -286,8 +389,20 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
                 <TableBody>
                   {shown.map((row) => {
                     const badge = statusBadge(row.status, row.paymentStatus);
+                    const sync = syncs.get(row.id);
+                    const erpTag = syncTag(sync);
+                    const rowBlocked = pushDisabledReason({ cfg: erpCfg, vendorRegistered, invoiceStatus: row.status });
                     return (
                       <TableRow key={row.id} className="voiced-history__row" onClick={() => onOpen(row.id)}>
+                        <TableCell onClick={(e: React.MouseEvent) => e.stopPropagation()}>
+                          <Checkbox
+                            id={`historySelect-${row.id}`}
+                            labelText={`Select invoice ${row.number}`}
+                            hideLabel
+                            checked={selected.has(row.id)}
+                            onChange={(_e, { checked }) => toggleOne(row.id, checked)}
+                          />
+                        </TableCell>
                         <TableCell>
                           <Link
                             href="#"
@@ -314,6 +429,13 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
                             </Tag>
                           ) : null}
                         </TableCell>
+                        {showErpColumn ? (
+                          <TableCell>
+                            <Tag type={erpTag.type} size="sm" title={erpTag.tooltip}>
+                              {erpTag.label}
+                            </Tag>
+                          </TableCell>
+                        ) : null}
                         <TableCell onClick={(e: React.MouseEvent) => e.stopPropagation()}>
                           <OverflowMenu
                             aria-label={`Actions for invoice ${row.number}`}
@@ -325,6 +447,17 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
                             <OverflowMenuItem itemText="Open" onClick={() => onOpen(row.id)} />
                             <OverflowMenuItem itemText="Export PDF (original as issued)" onClick={() => void onExport(row.id, "searchable", "original")} />
                             <OverflowMenuItem itemText="Export flattened PDF" onClick={() => void onExport(row.id, "flattened", "original")} />
+                            <OverflowMenuItem itemText="Export as voiced.invoice.v1 (JSON)" hasDivider onClick={() => void generic.run([row.id], "json")} />
+                            {erpOn || syncs.size > 0 ? (
+                              <OverflowMenuItem
+                                itemText="Send to ERPNext"
+                                hasDivider
+                                disabled={rowBlocked !== null}
+                                title={rowBlocked ?? undefined}
+                                onClick={() => askSend([row])}
+                              />
+                            ) : null}
+                            {canOpenInErpnext(sync) && erpOn ? <OverflowMenuItem itemText="Open in ERPNext" onClick={() => void onOpenErpnext(row.id)} /> : null}
                           </OverflowMenu>
                         </TableCell>
                       </TableRow>
@@ -363,6 +496,31 @@ export default function InvoiceHistory({ settings, active, onOpen }: Props) {
           )}
         </>
       )}
+
+      {!erpOn && !loading && rows.length > 0 ? (
+        <p className="voiced-muted" style={{ marginTop: "1rem" }}>
+          ERPNext is not set up.{" "}
+          <Link
+            href="#"
+            onClick={(e: React.MouseEvent) => {
+              e.preventDefault();
+              onOpenSettings();
+            }}
+          >
+            Set it up in Settings, Integrations
+          </Link>{" "}
+          to send invoices to it.
+        </p>
+      ) : null}
+
+      <SendToErpnextModal
+        open={sendTargets !== null}
+        invoices={sendTargets?.invoices ?? []}
+        skipped={sendTargets?.skipped ?? 0}
+        defaultSubmit={erpCfg?.submitOnPush ?? false}
+        onClose={() => setSendTargets(null)}
+        onFinished={() => void loadErpnext()}
+      />
     </div>
   );
 }

src/views/NewInvoice.tsx

@@ -59,6 +59,7 @@ import { SHORTCUT_LIST, useShortcuts } from "../hooks/useShortcuts";
 import PageSetupControls from "../components/PageSetupControls";
 import { useInvoicePdf } from "../hooks/useInvoicePdf";
 import { useInvoiceExport } from "../hooks/useInvoiceExport";
+import { autoPushIssued } from "../lib/erpnextUi";
 import ExportButton, { ExportModePicker } from "../components/ExportButton";
 import ExportFeedback from "../components/ExportFeedback";
 import { createExportDeps } from "../lib/exportDeps";
@@ -649,6 +650,16 @@ export default function NewInvoice({ settings, onSettingsChange, active, onActiv
     detachDraft();
     api.listClients().then(setClients).catch(() => {});
     void refreshDrafts();
+    // "Send on issue": in the background, so it never delays or fails the issue; the result arrives as a toast.
+    void autoPushIssued(
+      { getConfig: api.erpnextGetConfig, push: api.erpnextPushInvoice },
+      outcome.invoice,
+      settings.gstRegistration !== "unregistered",
+    )
+      .then((note) => {
+        if (note) toast[note.kind](note.title, note.subtitle);
+      })
+      .catch(() => {});
     // Unarchived invoices export by rendering and archiving first (see exportInvoice), so this still works.
     await exp.start(outcome.invoice, mode, "original");
     setSaving(false);