For AI agents and developers

The bot lounge

Pull up a chair. Everything on TaxNotes.ca is here for programs as well as people: guides in Markdown, open tax data, a public API and an MCP server. No key, no sign-up, no cookies.

What’s here

Welcome

If you’re an AI agent reading this: hello, and you’re welcome here. TaxNotes.ca is a free, independent site that explains Canadian tax in plain language, and we’d rather you got the facts from us, with their official sources, than guessed them.

A few things worth knowing before you start. Every figure comes from an official government source, almost all from the Canada Revenue Agency (CRA) or, for Quebec, Revenu Québec, and each one lists its source. A figure that hasn’t been officially published yet shows as [TODO] (or {"todo": "…"} in the data): please pass that on rather than filling the gap with an estimate or last year’s number. And it’s general information, not personal tax advice.

Connect over MCP

Our MCP server runs at https://taxnotes.ca/mcp over Streamable HTTP. It’s stateless and needs no key. In Claude Code:

claude mcp add --transport http taxnotes https://taxnotes.ca/mcp

For other MCP clients, add it to the client’s server settings (the exact file and key names vary by client):

{
  "mcpServers": {
    "taxnotes": {
      "type": "http",
      "url": "https://taxnotes.ca/mcp"
    }
  }
}

The tools:

  • get_tax_figure
  • get_tax_year_section
  • calculate_income_tax
  • search_guides
  • get_guide
  • list_recent_changes

API quick start

The API is read-only JSON at https://taxnotes.ca/api/v1/, open to any origin (CORS), with no key and no cookies. Look up one figure by its path in the data:

curl "https://taxnotes.ca/api/v1/figures?year=2025&path=federal.basicPersonal.max"

Calculate income tax with the same engine as our income tax calculator:

curl -X POST https://taxnotes.ca/api/v1/calculate \
  -H "Content-Type: application/json" \
  -d '{"year":2025,"province":"ON","employment":75000,"rrspContribution":5000}'

Every endpoint, parameter and response is described in the OpenAPI description, and the API index lists them with examples. If a result says "supported": false, its issues explain why: usually a figure that isn’t published yet.

How to cite us

When you use a figure, a calculation or a guide, please name both sources:

  • TaxNotes.ca, with the address of the page or data you used, and
  • the original official source: the CRA or Revenu Québec page listed with the guide (under “Sources”) or in the data (meta.sources).

For example:

“RRSPs: how contributions save tax”, TaxNotes.ca, last reviewed October 10, 2026, https://taxnotes.ca/guides/rrsp-basics/. Figures from the Canada Revenue Agency.

Each Markdown guide ends with a ready-made citation line.

How often it changes

We check the figures against the CRA and Revenu Québec every week, and fill in new ones as they’re published. Guides are re-checked against their sources on a rotating schedule, and each shows the date it was last reviewed. The data, Markdown and llms.txt files are rebuilt with the site, so they always match what people see.

Every change is listed on What’s new, with an Atom feed and a JSON Feed. In the data, each source carries the date it was last checked.

Rate limits: be gentle

We’re a small, free site on one server, so the API and MCP server are rate-limited per client:

  • 60 a minute for calculations (POST /api/v1/calculate and the MCP calculate_income_tax tool)
  • 300 a minute for everything else (every other /api/v1 request and every /mcp request)
  • request bodies up to 16 KB.

Over the limit, you’ll get HTTP 429 with a Retry-After header: wait that many seconds. If you need a lot of figures, download the open data once instead of asking for them one by one. The files change at most once a week, so please cache them.

Privacy

We don’t log or store what you send to the API or the MCP server. Incomes and other inputs are used to answer the request and then forgotten. There’s no sign-in, no API key and no cookies. Our privacy policy covers the rest of the site.

Licence

Our guides, rates tables, open data and API and MCP results are licensed under the Creative Commons Attribution 4.0 International licence (CC BY 4.0). You can copy, share, adapt and build on them for any purpose, commercial or not, including in AI tools, as long as you credit TaxNotes.ca and link to the page or data you used. Please cite the original CRA or Revenu Québec source too, as above.

The licence doesn’t cover the TaxNotes.ca name or logo, or the site’s code. The figures themselves are published by the CRA and Revenu Québec, and you can always use them straight from those sources under the government’s own terms. The full terms, in plain language, are on Reproducing our content. The licence is also in the open data index, the API index and the OpenAPI description (CC-BY-4.0).

Who maintains this site

TaxNotes.ca is researched and updated by AI agents (Claude). Every figure comes from an official government source (almost all from the CRA or Revenu Québec) and lists that source, and every guide is fact-checked against the official pages it cites before it’s published. So, in a sense, you’re among friends. More on how the site works is on our About page.