How to Use Model Context Protocol (MCP) in Cursor

Cursor connects to the server, lists capabilities, and invokes tools with your approval.

Install & configure in Cursor

1. Open settings → Features → MCP.
2. Click + Add New MCP Server.
3. Fill in:
   • Name: any friendly label (e.g., “Weather TS”).
   • Type: stdio or SSE.
   • Command / URL:
     • For stdio: a shell command that starts the server.
     • For SSE: the server’s SSE endpoint URL.
4. Save. If tools don’t appear, click Refresh in the MCP pane.

Example configurations

stdio (TypeScript weather server)

node ~/mcp-quickstart/weather-server-typescript/build/index.js

SSE (demo)

http://example.com:8000/sse

Tip: On macOS/Linux, make your server script executable so you can run it by name.

Using the tools inside Composer

Once the server is added:

• The Composer Agent will auto-invoke relevant tools when your prompt implies them.
• You can nudge usage by mentioning the tool name or describing its purpose.
• Cursor will ask for approval before running a tool. You can inspect parameters, approve, and see the tool’s structured response inline.

A quick smoke test

Try prompts like:

• “Use get_weather for Tokyo today and summarize.”
• “Read the repo README via the filesystem resource, then propose a one-line improvement.”

If you see an approval dialog and a response payload, you’re connected.

Environment variables (wrapping stdio servers)

Some servers need API keys or config. A simple wrapper script keeps your command clean:

#!/usr/bin/env bash
# file: start-weather.sh
export WEATHER_API_KEY="sk-..."
exec node ~/mcp-quickstart/weather-server-typescript/build/index.js

Then set the Command in Cursor to:

~/mcp-quickstart/start-weather.sh

You can also inline env vars:

WEATHER_API_KEY=sk-... node ~/mcp-quickstart/weather-server-typescript/build/index.js

Designing tools that work well in Cursor

• Name & describe clearly: models pick tools by name + description.
• Keep inputs small & typed: prefer concise JSON schemas; validate early.
• Return structure, not prose: let Cursor render; summarize only when needed.
• Be safe by default: require approval for destructive operations; log everything.
• Fail predictably: timeouts, retries, and helpful error messages.

Troubleshooting

Advanced tips

• Multiple servers: add one per domain (filesystem, search, CI, etc.).
• Versioning: include a version in your server name (e.g., “Docs Search v0.3”).
• Least privilege: read-only resources by default; narrow scopes for tools.
• Observability: log inputs/outputs/errors with request IDs for debugging.
• Compose flows: read a resource → call a tool → format with a prompt for clean handoffs.

Uninstall or disable

Open Settings → Features → MCP, select the server, and remove or toggle it off. Keep wrapper scripts and keys out of your repo if they’re local-only.

Wrap-up

MCP turns scattered integrations into one clean interface. In Cursor, that means faster setup, safer tool calls, and reusable servers you can share across projects. Add a server, run a smoke test, and start replacing glue code with something you won’t have to rewrite next time.