capitalcom-mcp 0.2.0

Model Context Protocol server for the Capital.com Open API (built on capitalcom-cli)

Capital.com MCP Server

Model Context Protocol server for the Capital.com Open API. Built on the tested capitalcom-cli broker engine (SDK), it exposes safe, guarded trading + market-data tools to MCP clients.

⚠️ Unofficial & educational. Not affiliated with Capital.com. Trading is risky and this is not financial advice. Trading is disabled by default; all trades are two-phase (preview → confirm → execute) with allowlists and size/rate limits. Start on a demo account. Apache-2.0 licensed.

Install

No clone required — uvx runs it in an isolated, throwaway environment and always fetches the latest tested release:

uvx capitalcom-mcp --help        # smoke test

Or install a persistent command with pipx:

pipx install capitalcom-mcp

1. Add your credentials (once)

Get an API key in the Capital.com app: Settings → API integrations (make a demo key first). Then run the wizard — it writes a 0600 file and prints the exact client snippet:

uvx capitalcom-mcp init

This writes ~/.config/capital-mcp/.env. Verify any time (no secrets printed):

uvx capitalcom-mcp doctor

Prefer a secret manager? Set CAP_API_KEY_CMD / CAP_IDENTIFIER_CMD / CAP_API_PASSWORD_CMD to a command that prints the secret (e.g. op read op://vault/..., pass ...). The secret is fetched at launch and never written to disk or to your client config.

2. Add the server to your client

Every client uses the same command/args/env shape. Pasting "CAP_ENV_FILE": "<path from init>" keeps secrets out of the client file; or put CAP_API_KEY/CAP_IDENTIFIER/CAP_API_PASSWORD directly in env.

Claude Desktop

~/Library/Application Support/Claude/claude_desktop_config.json (macOS) / %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "capitalcom": {
      "command": "uvx",
      "args": ["capitalcom-mcp"],
      "env": { "CAP_ENV_FILE": "/Users/you/.config/capital-mcp/.env" }
    }
  }
}

Claude Code

claude mcp add --transport stdio \
  --env CAP_ENV_FILE=/Users/you/.config/capital-mcp/.env \
  capitalcom -- uvx capitalcom-mcp

Cursor

~/.cursor/mcp.json (global) or .cursor/mcp.json (project):

{
  "mcpServers": {
    "capitalcom": {
      "command": "uvx",
      "args": ["capitalcom-mcp"],
      "env": { "CAP_ENV_FILE": "/Users/you/.config/capital-mcp/.env" }
    }
  }
}

VS Code (Copilot)

.vscode/mcp.json — note the root key is servers and type: "stdio":

{
  "servers": {
    "capitalcom": {
      "type": "stdio",
      "command": "uvx",
      "args": ["capitalcom-mcp"],
      "env": { "CAP_ENV_FILE": "/Users/you/.config/capital-mcp/.env" }
    }
  }
}

Windsurf

~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "capitalcom": {
      "command": "uvx",
      "args": ["capitalcom-mcp"],
      "env": { "CAP_ENV_FILE": "/Users/you/.config/capital-mcp/.env" }
    }
  }
}

ChatGPT

ChatGPT requires a remote server (stdio is not supported) — see Remote / VPS hosting. Once your server is reachable over HTTPS, enable Developer Mode (Settings → Connectors → Advanced) and add the server URL ending in /mcp. ChatGPT Deep Research connectors call two read-only tools, search and fetch, which this server implements; full custom tools require Developer Mode.

Remote / VPS hosting

Run with streamable-HTTP instead of stdio:

CAP_ENV_FILE=/home/you/.config/capital-mcp/.env \
  capitalcom-mcp run --transport http --host 0.0.0.0 --port 8000
# endpoint: http://<host>:8000/mcp

Or via env (handy in systemd): CAP_MCP_TRANSPORT=http, CAP_MCP_HOST, CAP_MCP_PORT. Put it behind a TLS-terminating reverse proxy for any public use.

Safety model

• Trading off unless CAP_ALLOW_TRADING=true and the EPIC is in CAP_ALLOWED_EPICS (or ALL).
• Two-phase execution; confirm=true required for mutations.
• Size, open-position, and daily-order caps; CAP_DRY_RUN=true blocks all executions. A TIMEOUT confirmation is ambiguous — reconcile, don't blindly retry.

Development

make install   # editable MCP + capitalcom-cli SDK from PyPI
make check     # ruff + mypy + pytest (offline; no network/credentials)

End-to-end tests drive every tool through the MCP against the demo API (read, watchlists, account switch, preview/execute/amend/close/cancel, streaming). They place real demo orders and clean up after themselves, so use a demo .env with trading + streaming enabled:

# demo .env: CAP_ALLOW_TRADING=true, CAP_ALLOWED_EPICS=GOLD, CAP_WS_ENABLED=true
CAP_MCP_E2E=1 pytest -m e2e -v

License

Apache-2.0. See LICENSE and NOTICE.