OpenAccountants
Open-source tax skills for AI across 134 countries — VAT/GST, income tax, social contributions. pip install openaccountants-mcp
Documentation
OpenAccountants
Open-source Tax Guides your AI can cite — reviewed by named, licensed accountants.
Every AI can do tax math. None of them can stand behind an answer. Here, real accountants put their name, credential and review date on the Guides your AI reads — publicly, on the record, in this repo.
1,855 Guides across 231 jurisdictions · 176 accountant-reviewed · 43 named accountants · 10,516 questions answered through connected AIs
Live from openaccountants.com — updated 2026-09-11 by the nightly sync.
Try it in 60 seconds
Add the hosted connector to Claude, ChatGPT, Cursor, Windsurf or any MCP client:
https://www.openaccountants.com/api/mcp
Guided setup: openaccountants.com/connect
Then ask a question your AI would otherwise guess at:
"What's the combined sales tax rate in Manatee County, Florida for 2026?"
Without OpenAccountants, models answer from training data. With it, the answer cites the current Guide — and names the accountant who reviewed it.
You: "I'm a freelancer in South Africa. What do I owe?"
↓ loads za-income-tax, za-provisional-tax
AI: ITR12 working paper · IRP6 provisional schedule
Medical credits · Retirement annuity deduction
─────────────────────────────────────────
Reviewed by Werner Britz CA(SA)
Prefer self-hosting or manual files?
- pip MCP server:
pip install openaccountants-mcp(mirrors this repo'spackages/) - Manual: download your jurisdiction's folder from
packages/and upload the files to your AI. Start with your country's main package;index.jsonis the machine-readable inventory.
Two states, greppable honesty
Every Guide is in exactly one state — and the repo greps honestly:
| State | Meaning |
|---|---|
| Accountant-reviewed | A named, licensed accountant reviewed the complete Guide. Their name is in the frontmatter (reviewed_by:) and on the public roster |
| Source-cited draft | Written from primary legislation, every figure cited to its source — not yet professionally reviewed |
⚠️ General reference, not advice. Guides may be incomplete, outdated, or wrong for your facts. Have a qualified professional review outputs before filing, payment, or action.
Are you an accountant?
Your name on the tax knowledge AI actually uses — with attribution built in:
- Build a Guide for the work you know cold: openaccountants.com/skills/new. It publishes credited to you, and lands in this repo under your name.
- Review a Guide in your jurisdiction — your name, credential and review date go on it, here and on every AI answer that cites it.
- Set your GitHub username in your profile and your platform edits are committed to this repo as you — your contribution graph reflects your work.
The current roster: VERIFIERS.md (generated nightly from the platform).
How it stays accurate
A tax library is only as good as its worst stale number, so machines re-check this one every night:
- The maths check re-reads every guide and flags sums that do not add up, tax bands with gaps, totals that do not total, and years that disagree.
- The source watch visits the official pages the figures came from and raises a hand when a page changes.
- The refresh engine re-derives the stalest guides from official sources on a fixed monthly budget, refusing to publish any figure without a link.
- The nightly exam tests whether AIs actually said what the guides say that day, or improvised. Improvisation gets caught, counted and fixed at the source.
The sync runs both ways: platform edits land here as commits under the author's own name, and merged PRs here flow back into what every AI serves, credited to you. A guide with an accountant's byline never changes without that accountant's one-click approval.
The whole story, in plain words: openaccountants.com/how-it-works
Contributing
Edit skills/** only — everything else regenerates automatically:
packages/,index.json,llms-full.txt— generated nightly; never edit in a PR- Merged source PRs are credited to you and must be confirmed as ingested before the next platform export
- Full guide: CONTRIBUTING.md · Layout: docs/REPO-LAYOUT.md
For developers
| What | Where |
|---|---|
| Guide source (per jurisdiction) | skills/ |
| Per-country bundles (generated) | packages/ |
| Machine-readable inventory | index.json |
| LLM entry point | llms.txt |
| Python MCP server | mcp/ · PyPI |
| Repo architecture + sync | docs/REPO-LAYOUT.md · docs/WEBSITE-SYNC.md |
API and platform integrations: openaccountants.com/for-developers
License
- Code (mcp/, scripts/, tools/): AGPL-3.0
- Guide content: OpenAccountants Guide License v1.0 — see LICENSING.md; commercial options in COMMERCIAL-LICENSING.md
Contact: info@openaccountants.com · Security policy · Cite this repo