odoo-addon-account-ostax 19.0.0.1.17

OpenSalesTax connector for Odoo 19 — destination-based US sales tax via the OpenSalesTax engine

opensalestax-odoo

Destination-based US sales tax for Odoo Community. Replaces static tax-rate configuration with live calculation against an OpenSalesTax engine — your own self-hosted instance, no per-transaction fees, no SaaS lock-in.

The free, self-hostable answer to Avalara on Odoo Community Edition. Available on all four current Odoo major versions — 16.0, 17.0, 18.0, and 19.0 — same module, branch-per-version per the OCA convention.

Branch matrix

Pick the branch matching your Odoo install. Releases are independent per branch.

Odoo version	Branch	PyPI artifact	Status
16.0	16.0	odoo-addon-account-ostax==16.0.*	shipping
17.0	17.0	odoo-addon-account-ostax==17.0.*	shipping
18.0	18.0	odoo-addon-account-ostax==18.0.*	shipping
19.0	19.0	odoo-addon-account-ostax==19.0.*	shipping

What you get

• Sales orders, customer invoices, credit notes/refunds, POS — all with destination-based per-jurisdiction US tax
• Per-jurisdiction breakdown stored on every move (state / county / city / district), rendered on the form view for full audit trail
• Per-product taxability category (product.template.ostax_category — general / clothing / groceries / prescription_drugs / prepared_food / digital_goods); engine applies per-state taxability rules (e.g. Minnesota exempts clothing, New York taxes prepared food differently than groceries)
• Per-category default with parent-walk inheritance — mark "Apparel" as clothing once on product.category, every product underneath inherits unless overridden. Closest-ancestor wins.
• Per-worker engine-response cache (~1 hour sliding TTL) — repeat calculations within the same hour for the same line shape skip the engine. Helpful for batch invoicing, recurring orders, multi-line carts.
• Customer exemption certificates on res.partner
• Multi-company support — settings scoped per company
• Fiscal-position interop — non-US partners route through Odoo's standard "Export" mapping; the connector only engages for US shipping addresses
• Settings page with engine connection test, fail-soft toggle
• Optional admin debug log of recent calculations
• Optional 90-day archive cron for jurisdictions you've stopped shipping to

What's deferred to v0.2

• Vendor bills + use-tax accrual. Use tax is owed at the buyer's location, not the vendor's; v0.1 doesn't yet implement the buyer-location code path. Vendor bills (and any purchase-typed catalog tax) bypass the connector and fall through to Odoo's standard catalog rates — see v0.1.15.
• POS live-quote. Server-authoritative compute on order close works; per-line live JS-side round-trip on each line-add is a v0.2 enhancement.

Install

The same package serves all four Odoo majors via version-prefix selectors. Pick the one that matches your Odoo install:

# 1) The Python SDK (same on every branch):
pip install opensalestax

# 2) The connector (pick ONE matching your Odoo major):
pip install 'odoo-addon-account-ostax>=16.0.0.1.12,<17.0'  # Odoo 16
pip install 'odoo-addon-account-ostax>=17.0,<18.0'         # Odoo 17
pip install 'odoo-addon-account-ostax>=18.0,<19.0'         # Odoo 18
pip install 'odoo-addon-account-ostax>=19.0,<20.0'         # Odoo 19

Note for Odoo 16 users: The 16.0.0.1.11 wheel is broken (a tools.ormcache annotation-stripping bug — see CHANGELOG for v0.1.12). Always pin >=16.0.0.1.12.

Or install from source — replace <NN.0> with your major:

git clone -b <NN.0> https://github.com/ejosterberg/opensalestax-odoo.git
cd opensalestax-odoo
# Symlink or copy account_ostax/ into your Odoo addons-path

Then in Odoo: Apps → search "OpenSalesTax" → Install, then Settings → Accounting → OpenSalesTax to configure the engine URL.

Quick start

After install, in Settings → Accounting → OpenSalesTax:

1. Engine URL — point at your OpenSalesTax engine (e.g. http://10.0.0.50:8080). Self-hosted; see the engine project at https://github.com/ejosterberg/open-sales-tax for a docker-compose deployment.
2. API key — leave blank for unauthenticated engines (default).
3. Click "Test Connection" — should report engine version + DB status + RTT in milliseconds. If it fails, check the engine is reachable from the Odoo host and the URL is correct.
4. Fail-soft — recommended ON during initial rollout. The connector falls through to catalog rates if the engine is unreachable rather than blocking invoice posting. Switch off once you trust connectivity.

That's it for sales tax. Create a US customer with a 5-digit ZIP, add a sale order or invoice, and the connector engages automatically.

Configuring per-product / per-category taxability

For most products, leave everything at the defaults — the engine treats unflagged products as general taxable goods.

For products in special-taxability categories (clothing, groceries, prescription drugs, prepared food, digital goods), set the category on:

• The product (Inventory → Products → form view → Accounting tab → OST tax category), OR
• The product's internal category (Inventory → Configuration → Product Categories → form view → OST tax category default) — every descendant product inherits unless overridden.

The lookup precedence is: per-product → product's category → walk up parent_id until a value is found → fall back to general.

How it works

The connector overrides Odoo's tax computation entry points (the new batch tax engine on 18+, legacy compute_all on 16/17). When a US customer with a valid 5-digit ZIP is on an outbound flow — sale order, customer invoice, credit note, POS order — Odoo's tax pipeline calls the OpenSalesTax engine via the Python SDK and replaces the static catalog rate with a per-jurisdiction breakdown.

Non-US partners fall through to Odoo's standard fiscal-position handling. Vendor bills and other inbound moves currently bypass the connector (use-tax accrual lands in v0.2 — see "What's deferred to v0.2" above).

Engine compatibility

Tested against OpenSalesTax engine v0.54.1+. Minimum: v0.22 — earlier versions had an SD-state-bleed bug (engine GitHub issue #37 — closed in v0.22.0). The connector requires the v1 HTTP API (/v1/calculate, /v1/health, /v1/states, /v1/rates).

Pin the engine in production. The connector is forward-compatible within the v1 API contract; if a future engine bumps to v2, the connector will need a corresponding bump.

Troubleshooting

"Test Connection" works but invoices don't engage. Check that the customer has country_id = United States and a 5-digit-or-longer zip. Non-US customers and US customers with malformed ZIPs route to Odoo's standard fiscal-position handling — not an OST bug.

Tax appears as Tax 15% (or your chart's default). You're on v0.1.2 or earlier, before per-type tax groups landed. Upgrade to v0.1.3 or later — the synthetic taxes now sit under OpenSalesTax — State / County / City / District groups.

Vendor bills show catalog rates. Expected on v0.1.x — vendor bills fall through to Odoo's catalog handling. Proper use-tax accrual at the buyer's location is v0.2 work.

Engine is reachable but calls return errors. Enable Debug log on the settings page and check Settings → Technical → OpenSalesTax Calc Log for the last ~50 calls per company (status code, RTT, engine version). If 4xx, the request is malformed (usually a non-numeric ZIP); if 5xx, the engine itself is failing — pull engine logs.

Invoice posts with amount_tax = 0 despite a US customer. The customer probably has an OST exemption certificate set (res.partner → OST exemption tab). Exempt partners short-circuit to zero tax with no engine call.

Calculation only

Tax calculations are provided as-is for convenience. The merchant is solely responsible for tax-collection accuracy and remittance to the appropriate jurisdictions. Verify against your state Department of Revenue before remitting.

This module does NOT file returns, remit collected tax, validate addresses, or provide legal/tax advice.

License

LGPL-3 (or-later) per the project's per-platform license carve-out. Apache-2.0 SDK consumed. DCO sign-off required on every commit; no AI co-author trailers. See CONTRIBUTING.md.

Status

Production-grade across all four Odoo majors. v0.1.17 is shipping on PyPI as odoo-addon-account-ostax==<branch>.0.1.17 for 16.0, 17.0, 18.0, and 19.0. Per-branch test workflows green on every branch; 49 unit tests pass on real Odoo + Postgres in Docker.

What works on every branch:

• Real destination-based per-jurisdiction US sales tax on every customer invoice, sale order, credit note (state / county / city / district splits in the totals area)
• Line-level OST jurisdiction tags persisted on posted invoices
• Engine audit JSON captured on _post() (engine version, calc timestamp, full per-jurisdiction detail)
• Per-product + per-category OST taxability mapping
• Per-worker engine-response cache (~1h sliding TTL)
• Customer exemption certificate handling
• Multi-company isolation
• Settings page + Test Connection action
• Optional admin debug log
• Optional 90-day archive cron for jurisdictions you've stopped shipping to

How it's wired:

• Odoo 18 + 19 override account.tax._add_tax_details_in_base_lines using the official manual_tax_amounts injection mechanism — same hook the proprietary Avalara module uses, no internal-API fragility.
• Odoo 16 + 17 override the legacy compute_all method (the new batch engine arrived in 18.0).
• Per-version settings xpath: 16 uses //div[@data-key='account']; 17/18/19 use //app[@name='account'].

Verified end-to-end on real Odoo + Postgres in Docker against the live engine, including Odoo's official US chart of accounts (l10n_us): $100 invoice to MSP (ZIP 55401) produces amount_tax=9.03 with 6 per-jurisdiction lines.