mcp

The Paper MCP Server (@paperinvest/mcp-server) provides an MCP endpoint that lets AI coding assistants interact with the Paper Trading API. It exposes tools to fetch real-time quotes, batch quotes for multiple symbols, place simulated/paper orders, and inspect portfolio positions and P&L. Typical usage involves starting the server in your environment and wiring it into your MCP-enabled assistants (e.g., Cursor or Claude Desktop) using the provided integration configurations. Once running, you can request quotes, place trades in a simulated environment, and query portfolios to power AI trading prompts with live, paper-trade data.

The server expects your Paper API credentials to be available via environment variables. The key capabilities include: paper.quote(symbol) for a real-time NBBO quote, paper.quotesBatch(symbols[]) for multiple quotes in one request, paper.order({ ... }) to place a simulated order (market/limit/stop, etc.), and paper.portfolio(id) to retrieve positions and P&L. See the repository examples for concrete scripts and configurations that demonstrate how to call these tools from common MCP clients.

Prerequisites:

• Node.js 16+ (recommended)
• npm (comes with Node.js) or npm/yarn

Install the MCP server (global CLI) and run it via npx or a global install:

Option A: Use npx (no global install required)

# Start the MCP server via npx (will fetch the package on demand)
npx -y @paperinvest/mcp-server

Option B: Global installation (preferred for CLI usage, as recommended in the README)

npm i -g @paperinvest/mcp-server
# Then run the server directly (the CLI name is typically paper-mcp-server)
paper-mcp-server

Configuration (environment variables):

export PAPER_API_KEY=your_api_key
export PAPER_API_BASE_URL=https://api.paperinvest.io  # optional, defaults if omitted

If you choose to use npx without a global install, you can also preconfigure the environment when launching the command:

PAPER_API_KEY=your_api_key PAPER_API_BASE_URL=https://api.paperinvest.io npx -y @paperinvest/mcp-server

Once configured, the MCP server will expose its endpoints for the MCP clients and integrations (Cursor, Claude Desktop, etc.).

Tips and common considerations:

• Ensure PAPER_API_KEY is set in the same environment as your MCP client to avoid credential errors.
• If you update your API URL, set PAPER_API_BASE_URL to point to the correct Paper API endpoint.
• When integrating with Cursor or Claude Desktop, place the provided mcpServers.paper block into your respective config files (e.g., .cursor/mcp.json or Claude config) so the client can locate and connect to the server.
• If the server cannot connect, verify network access to https://api.paperinvest.io and that the API key is valid.
• For troubleshooting, restart the client (Cursor/Claude) after changing environment variables or the server configuration, and ensure paper-mcp-server is discoverable in PATH when using a global install.