TaxGraph

MCP server for Canadian tax research. Search legislation, CRA guidance and case law; retrieve definitions, citations and source passages.

Server URL: https://taxgraph.ca/mcp
Transport: Streamable HTTP. Authentication: none.

Connect

Try on the web

Ask on tax.wiki. Powered by TaxGraph.

Claude
  1. Open Customize → Connectors. Select + Add → Add custom connector.
  2. Name it TaxGraph and enter https://taxgraph.ca/mcp.
  3. Continue through setup. Select No sign in under Authentication, then Add.
  4. In a chat, open + → Connectors and enable TaxGraph.

Workspace connectors may need to be added by an administrator. Claude setup reference.

ChatGPT Web
  1. Open Settings → Security and login and enable Developer mode.
  2. Open Plugins and select +.
  3. Name the connection TaxGraph. Use Canadian tax research as the description and https://taxgraph.ca/mcp as the server URL. Create the connection; no TaxGraph credentials are required.
  4. Start a chat and select TaxGraph from + → More.

Developer mode availability depends on your account and workspace policy. ChatGPT setup reference.

ChatGPT Desktop & Codex
  1. Open Settings → Plugins. Select Add → Add MCP Server.
  2. Enter TaxGraph as the name and select Streamable HTTP.
  3. Enter https://taxgraph.ca/mcp as the URL. No authentication is required.
  4. Save the connection and restart if prompted. In the chat composer, type /mcp to check that TaxGraph is connected.

If your settings show MCP servers, select Add server there. ChatGPT desktop setup reference.

Microsoft 365 Copilot

Connect through an agent in Copilot Studio.

  1. Create or open an agent. Open Tools → Add a tool → New tool → Model Context Protocol.
  2. Enter TaxGraph as the server name, Canadian tax research as the description and https://taxgraph.ca/mcp as the server URL.
  3. Select None for authentication, then Create. Create a new connection and select Add to agent.
  4. Test and publish the agent. Under Channels → Teams and Microsoft 365 Copilot, enable Make agent available in Microsoft 365 Copilot and add the channel. Install the agent, then select it in Microsoft 365 Copilot to start a chat.

Requires access to a Copilot Studio environment; organization policies may require administrator approval. MCP setup reference · Microsoft 365 publishing reference.

Claude Code
claude mcp add --transport http taxgraph https://taxgraph.ca/mcp

Example usage

Definitions in context

Use TaxGraph to compare “excluded amount” in paragraph 20(1)(e) with the same term in subsection 120.4(1). Explain where each definition applies and quote the source wording.

CRA guidance and publication history

Use TaxGraph to find CRA guidance on subsection 85(1). Identify archived or replaced publications, follow their replacement history, and quote relevant passages with their surrounding context.

Later applications of a decision

Use TaxGraph to find later tax decisions applying Canada Trustco (2005 SCC 54). Compare how the courts used the decision, quote the supporting judgment paragraphs, and retrieve the Income Tax Act provisions cited in those passages.

Sources

LegislationIncome Tax Act; Income Tax Regulations.
CRAFolios, interpretation bulletins, technical news and severed technical interpretations.
Case lawTax-relevant decisions from the TCC, FCA, Federal Court and Supreme Court of Canada.
FinanceDepartment of Finance explanatory notes.