Support MCP Debugging with any command (e.g. `bun`, `deno`, `pnpm run server.ts`)

[pattobrien]

It'd be great to have support for other JS runtimes during debug like bun and deno, rather than just node. Additionally, it would be even more convenient if debug mode could be triggered via any CLI command, so that e.g. package.json scripts could be used too.

I can imagine that stepping into the MCP server's code would be very useful during debugging, but as of right now it would require re-configuring my monorepo's setup to support running with node.

[pattobrien]

FWIW, my current workaround is to use a loader like tsx:

{
  "servers": {
    "my-server": {
      "command": "node",
      "args": [
        "--import",
        "tsx/esm",
        "--experimental-strip-types",
        "/path/to/my/server.ts"
      ],
      "dev": {
        "watch": "src/**/*.ts",
        "debug": {
          "type": "node"
        }
      }
    }
}

[connor4312]

npm/pnpm run is not really doable because they don't run the server directly, they spawn a child process, which we can't debug in this case for reason 😛 Thus I restricted it to node just to avoid confusion. But I agree that adding deno, bun, etc. would make sense.

[connor4312]

Code pointer if you want to PR:

vscode/src/vs/workbench/contrib/mcp/common/mcpDevMode.ts

Line 142 in aa4e7c1

if (!/node[0-9]*$/.test(launch.command)) {