VS Code agent mode

VS Code's agent mode can call MCP servers, and the DebugAI extension brings one with it. Once the extension is installed and signed in, it registers a server named DebugAI with the same three tools the npm package has: lookup_error, debug_error and report_outcome.

You need VS Code 1.101 or later. You do not need Node.js for this one: the server runs on VS Code's own runtime.

Use the debugai lookup_error tool on this error: TypeError: Cannot read properties of undefined (reading 'name')

How the bundled server differsCopy Anchor Link

It is the same protocol surface as @debugai/mcp on npm. A few things follow from living inside the extension:

• It answers for the first folder open in VS Code. The agent's errors are filed under the same project as the ones you debug from the editor, so the agent and the DebugAI panel share one memory for that folder. Open a different folder and the extension updates the server to match. With no folder open, it reads no local files.
• projectRoot is for an error from somewhere else, a folder that is not the one open in VS Code. A filePath does not pick the project here, as it does on the npm server.
• Sign-in happens in the extension, not inside the chat. When the key is rejected, the server tells the agent to have you run DebugAI: Set API Key from the Command Palette.
• Its footer says so. Each answer's footer carries DebugAI MCP <version> (VS Code), so you can tell which server replied.

Without the extensionCopy Anchor Link

To give VS Code's agent the tools without installing the extension, add the npm server:

npx -y @debugai/mcp login
npx -y @debugai/mcp install --client=vscode

Then run MCP: List Servers from the Command Palette to confirm it is there. This path needs Node.js 18.14.1 or later.

setup skips VS Code on purpose. With the extension installed, doctor says so:

· VS Code (native MCP) — no entry here, which is right with the DebugAI extension installed

The entry goes under servers in mcp.json, in VS Code's user folder:

~/Library/Application Support/Code/User/mcp.json

{
  "servers": {
    "debugai": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@debugai/mcp@latest"]
    }
  }
}

• Your key is never written into this file. It lives in ~/.debugai/config.json with 0600 permissions.
• Before changing the file, install saves a copy beside it, named mcp.json.debugai-backup-<timestamp>. Every other setting in the file is kept.
• If the file has comments, the rewrite drops them, and install warns you when it does. The backup keeps them.

NextCopy Anchor Link

• Work with your agent: the lookup, debug and report loop, and how to point an answer at the right project.
• MCP server troubleshooting: doctor output, sign-in from inside a chat, and the errors an agent can get back.