If your product touches Canadian tax — invoicing, bookkeeping, gig-platform tooling, payroll, an AI agent — you have two bad options today: maintain your own rate tables and hope you catch every CRA change, or let a model guess. We already maintain the third option: engines whose every figure traces to a published source, re-verified on a schedule, with 300,000+ automated assertions gating every release.
Free today, no key required
- 🤖 MCP server (this site) —
POST https://freelancertax.ca/mcp: six agent-callable tools (self-employed tax estimate, CPP, GST/HST registration test, Quick Method comparison, instalment plan, deadlines). JSON-RPC 2.0; every answer carries its verification date, source links and the engine's estimates-only disclaimer. - 💼 Payroll MCP server —
POST https://canada-payroll.ca/mcp: employer total cost and employee take-home across all 13 provinces and territories, plus net-to-gross where fully verified. - 📊 Open dataset (CC BY 4.0) — versioned JSON rate tables at /data/v1/, mirrored on GitHub. Attribution required: a link to freelancertax.ca.
A first call, no signup:
curl -X POST https://freelancertax.ca/mcp \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'Every tools/call answer is an envelope of {ok, data, summary, source, integrity, disclaimer} — the figures inside are computed by the same engines that power the calculators on this site, never stored in the handler.
The API tier we'll build if you want it
The MCP servers and dataset stay free. What some teams have asked about is a proper commercial surface on the same engines:
- 🔑 Metered REST endpoints — API keys, quotas, stable versioned routes for self-employed tax, CPP, GST/HST and payroll gross↔net.
- 📅 Guaranteed figure updates — when the CRA publishes next year's figures, verified endpoints update on a committed timeline, with changelogs.
- 📜 Commercial terms — a real license (no attribution requirement), support, and an accuracy methodology you can show your own auditors: how we verify.
Planned pricing (self-serve, no sales calls): Free — rate-limited, attribution required · Developer $29/mo · Commercial $99/mo. Founding waitlist members get first access and a say in limits and endpoints. Pricing is planned, not final, until launch.
The honest part
We build this only if enough people want it — that's how everything on this site gets made. Joining the waitlist is the vote. One email if it ships, zero spam either way, and the free tier above exists regardless.
Join the API waitlist — tell us what you'd build and we'll shape the endpoints around it.
Who this is for
Bookkeeping and invoicing SaaS adding Canadian tax features · gig-platform and marketplace tooling · indie payroll builders · agent developers who need Canadian math their model can't safely guess. If that's you and the waitlist isn't enough, the verification methodology and the open dataset are the best places to evaluate us.
All engine outputs are estimates for planning purposes — not tax, legal, or accounting advice. Planned tiers and pricing describe a product under validation and may change or not ship; the free MCP servers and open dataset are live today.