Add Browser-Based MCP Tools to Cursor AI Editor

What is Cursor?

Cursor is the most popular AI-native code editor, built on VS Code. Its agent mode can plan, write, and execute code across your entire codebase. With MCP support, Cursor's agent can call external tools — querying databases, fetching APIs, running code — making it dramatically more powerful for complex tasks.

Prerequisites

• Cursor version 0.40+ — cursor.com
• Node.js 18+ — nodejs.org
• Agent MCP Studio open at agentmcp.studio

Step-by-Step Setup

1. Get your relay URL from Agent MCP Studio

   Open agentmcp.studio → Settings → MCP Relay Bridge. Copy the session URL (starts with wss://agentmcp.studio/api/relay/). Click Connect — the status will show "Waiting for bridge.js…"

2. Download bridge.js and install dependencies

   curl -O https://agentmcp.studio/bridge.js
   npm install ws   # in the same folder

3. Create or edit the Cursor MCP config

   Cursor looks for MCP servers in two locations:

   • Global (all projects): ~/.cursor/mcp.json
   • Project-level: .cursor/mcp.json in your project root

   Create or edit the global config:

   {
     "mcpServers": {
       "agent-mcp-studio": {
         "command": "node",
         "args": [
           "/absolute/path/to/bridge.js",
           "wss://agentmcp.studio/api/relay/YOUR-SESSION-UUID"
         ]
       }
     }
   }

4. Reload Cursor's MCP configuration

   Open Cursor Settings (Cmd/Ctrl+,) → search for MCP → click "Reload MCP servers". Or simply restart Cursor.

   In Cursor's Settings → MCP tab you should now see agent-mcp-studio listed with a green indicator. The bridge chip in Agent MCP Studio will turn 🟢 Live.

5. Use tools in Cursor's agent

   Open Cursor's chat with Agent mode enabled (not Ask or Edit). Type something that would require a tool — for example if you registered a fetch_webpage tool: "Fetch the content of example.com and summarise it." Cursor's agent will call your browser tool automatically.

Project-Level vs Global Config

Troubleshooting

Tools not showing in Cursor agent

• Confirm Agent MCP Studio shows 🟢 Live in the bridge chip
• Make sure you're using Agent mode in Cursor chat (not Ask or Edit)
• Check the MCP tab in Cursor settings for error messages
• Run bridge.js manually in terminal to see raw output: node bridge.js wss://...YOUR-UUID

Session UUID changes on browser refresh

The UUID is stable across refreshes — it only changes if you click "New session" in the studio. You do need to click Connect again after a refresh, but your Cursor config stays valid.

Frequently Asked Questions

How do I add an MCP server in Cursor?▾

Edit (or create) .cursor/mcp.json in your home directory. Add your server under the mcpServers key with command and args — then restart Cursor. Agent MCP Studio's bridge.js works as a drop-in MCP server command.

Where is the Cursor MCP config file?▾

Global config: ~/.cursor/mcp.json (macOS/Linux) or %USERPROFILE%\.cursor\mcp.json (Windows). You can also place a .cursor/mcp.json in a specific project folder to scope it to that workspace.

Does Cursor MCP work on Windows?▾

Yes. Cursor's MCP support works on macOS, Linux, and Windows. On Windows, use the full absolute path with escaped backslashes or forward slashes for the bridge.js location in your mcp.json.

Why isn't my MCP server showing in Cursor?▾

Most common causes: wrong absolute path to bridge.js, UUID mismatch between mcp.json and your Studio session, Cursor not fully restarted after saving the config, or Node.js not in your PATH.

Can Cursor use multiple MCP servers at once?▾

Yes — Cursor supports multiple servers in mcp.json. Each entry in mcpServers is an independent server. Agent MCP Studio's tools will appear alongside tools from any other MCP servers you configure.

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