How to add CongressMCP to Claude Desktop

91+ congressional data tools — bills, votes, members, committees, hearings — via the Congress.gov API. Paste the config into ~/Library/Application Support/Claude/claude_desktop_config.json and restart Claude Desktop.

Last updated June 14, 2026 · 32★ · stdio · apikey

Claude Desktop config for CongressMCP

uvx congressmcp

{
  "mcpServers": {
    "congressmcp": {
      "command": "uvx",
      "args": [
        "congressmcp"
      ],
      "env": {
        "CONGRESS_API_KEY": "your-api-key-here"
      }
    }
  }
}

Requires `uv` (the Python package runner). Install it from https://docs.astral.sh/uv/ if `uvx` is not found.

Setup steps

1Open Claude Desktop → Settings → Developer → Edit Config (this opens ~/Library/Application Support/Claude/claude_desktop_config.json).
2Paste the CongressMCP config below under the top-level "mcpServers" key.
3Fill in any placeholder secrets (API keys, paths) in the snippet.
4Save the file, then fully quit and reopen Claude Desktop.
5Open a chat and confirm CongressMCP's tools appear under the 🔌 tools menu.

Before you start

A free Congress.gov API key (sign up at api.congress.gov/sign-up)
uv / uvx (or pip) to install and run the congressmcp package
An MCP client such as Claude Desktop, Cursor, or VS Code

What CongressMCP can do in Claude Desktop

Bills (16 operations)

Search bills, fetch details, text, actions, amendments, cosponsors, and subjects.

Amendments (7 operations)

Search amendments and retrieve details, actions, sponsors, and text.

Treaties & Summaries (5 operations)

Treaty search, actions, committees, and text; plus bill summaries.

Members & Committees (13 operations)

Search members by name, state, or district; sponsored legislation; committee bills and reports.

Voting & Nominations (13 operations)

House and Senate votes, nominations, and roll calls.

Records & Hearings (10+ operations)

Access the Congressional Record, hearings, CRS reports, and committee prints.

Security

Requires a free Congress.gov API key (CONGRESS_API_KEY), set via the env block in your MCP client config. Sign up at api.congress.gov/sign-up.

CongressMCP + Claude Desktop FAQ

Where is the Claude Desktop config file?

Claude Desktop reads MCP servers from ~/Library/Application Support/Claude/claude_desktop_config.json. Paste the CongressMCP config there under the "mcpServers" key and restart the client.

Is CongressMCP safe to use with Claude Desktop?

Requires a free Congress.gov API key (CONGRESS_API_KEY), set via the env block in your MCP client config. Sign up at api.congress.gov/sign-up.

Is the Congress.gov API key free?

Yes. Sign up at api.congress.gov/sign-up — it takes about 30 seconds and is completely free.

Which MCP clients are supported?

Claude Desktop, Cursor, VS Code, and any other MCP client. The README provides config for Claude Desktop (claude_desktop_config.json), VS Code (.vscode/mcp.json), and Cursor (~/.cursor/mcp.json).

Can I self-host it over HTTP?

Yes. Run from source with `congressmcp --transport streamable-http --port 8000`, or set MCP_TRANSPORT=streamable-http. The default transport is stdio for local MCP clients.

View repo Full CongressMCP page