Usage within PhpStorm (Jetbrains)?

[rolandorojas]

Environment: Windows 11
Node version: 20.17.0

I set up the MCP for PhpStorm's Junie, but I cannot get it to start. This is the error I get

StandaloneCoroutine was cancelled

Rollbar MCP Server running on stdio node:events:497 throw er; // Unhandled 'error' event ^ Error: EPIPE: broken pipe, write at Socket._write (node:internal/net:61:18) at writeOrBuffer (node:internal/streams/writable:570:12) at _write (node:internal/streams/writable:499:10) at Writable.write (node:internal/streams/writable:508:10) at file:///C:/Users/rolan/AppData/Local/npm-cache/_npx/8679b797aad9220b/node_modules/@modelcontextprotocol/sdk/dist/esm/server/stdio.js:69:30 at new Promise ( ) at StdioServerTransport.send (file:///C:/Users/rolan/AppData/Local/npm-cache/_npx/8679b797aad9220b/node_modules/@modelcontextprotocol/sdk/dist/esm/server/stdio.js:67:16) at Promise.resolve.then.then.capturedTransport.send.jsonrpc (file:///C:/Users/rolan/AppData/Local/npm-cache/_npx/8679b797aad9220b/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:162:108) at process.processTicksAndRejections (node:internal/process/task_queues:95:5) Emitted 'error' event on Socket instance at: at emitErrorNT (node:internal/streams/destroy:169:8) at emitErrorCloseNT (node:internal/streams/destroy:128:3) at process.processTicksAndRejections (node:internal/process/task_queues:82:21) { errno: -4047, syscall: 'write', code: 'EPIPE' } Node.js v20.17.0

If I start it from the command line, it does appear to work:

>set ROLLBAR_ACCESS_TOKEN=<real-token-here>
> C:\nvm4w\nodejs\npx.cmd -y @rollbar/mcp-server@latest --stdio

The process starts successfully with the message "Rollbar MCP Server running on stdio."

Any ideas?

[brianr]

@rolandorojas thanks for the issue!

I don't have ready access to a Junie environment, but got the following tips from gpt5 - do any of these resolve your issue?

---

Short answer: Junie is killing the npx … @rollbar/mcp-server process almost immediately, so the server’s next write to stdout hits a closed pipe → EPIPE. On Windows this nearly always comes from one of three things: (1) Junie can’t find npx.cmd (PATH problem), (2) env vars (like ROLLBAR_ACCESS_TOKEN) aren’t being passed to the spawned process, or (3) Junie aborts the launch (timeout / config parse failure), which shows up in JetBrains logs as “StandaloneCoroutine was cancelled.” Here’s how to fix it.

Fix it in PhpStorm → Junie

1. Use the full Windows path to npx.cmd (Junie doesn’t spawn via a shell, so npx may not resolve from PATH).

• In Settings → Tools → Junie → MCP Settings, add/edit the JSON to something like:

{
  "mcpServers": {
    "rollbar": {
      "type": "stdio",
      "command": "C:\\nvm4w\\nodejs\\npx.cmd",
      "args": ["-y", "@rollbar/mcp-server@latest"],
      "env": {
        "ROLLBAR_ACCESS_TOKEN": "${input:rollbar_token}"
      }
    }
  }
}

• If your Node/npm live elsewhere, point command at that exact npx.cmd (e.g. C:\\Program Files\\nodejs\\npx.cmd).

2. Pass the token via Junie, not your shell. The shell set ROLLBAR_ACCESS_TOKEN=… you tested only affects that console. Junie launches its own process and won’t see it unless you put it under "env" in the config (as above). The official Junie docs show this pattern and recommend setting env in the MCP config. ([JetBrains]1)

3. (Optional) Wrap with cmd.exe if your path has spaces or quoting is flaky. Some early Junie builds on Windows are sensitive to paths with spaces. This variant is more tolerant:

{
  "mcpServers": {
    "rollbar": {
      "type": "stdio",
      "command": "C:\\Windows\\System32\\cmd.exe",
      "args": [
        "/d", "/s", "/c",
        "C:\\nvm4w\\nodejs\\npx.cmd",
        "-y", "@rollbar/mcp-server@latest"
      ],
      "env": { "ROLLBAR_ACCESS_TOKEN": "${input:rollbar_token}" }
    }
  }
}

(There are multiple active JetBrains tickets about Windows path/launch quirks and “StandaloneCoroutine was cancelled.”) ([YouTrack]2, [GitHub]3)

4. Make sure your Junie build supports stdio MCP and is up-to-date. Junie currently supports stdio-only MCP servers; updating to the latest PhpStorm/Junie fixes a handful of Windows launch bugs. ([JetBrains]1)

5. Keep the args exactly like the README. The Rollbar MCP server is already an stdio server; you don’t need a --stdio flag for Junie—just run via npx with the package name and provide ROLLBAR_ACCESS_TOKEN. (That’s the canonical config from the repo README.) ([GitHub]4)

Why your CLI test works but Junie fails

• In your shell, npx is found and the env var is set → server stays up.
• In Junie, missing env or a bad command path causes the IDE to terminate the child process; the server tries to write its next JSON-RPC frame and hits EPIPE because stdin/stdout were already closed by the IDE. That’s exactly the failure mode JetBrains documents (and you’ll see “StandaloneCoroutine was cancelled” in the IDE). ([JetBrains]1, [YouTrack]5)

Known-good minimal config (copy/paste)

{
  "mcpServers": {
    "rollbar": {
      "type": "stdio",
      "command": "C:\\nvm4w\\nodejs\\npx.cmd",
      "args": ["-y", "@rollbar/mcp-server@latest"],
      "env": {
        "ROLLBAR_ACCESS_TOKEN": "${input:rollbar_token}"
      }
    }
  }
}

After saving, restart PhpStorm (or at least disable/re-enable the server in MCP Settings) and check Settings → Tools → Junie → MCP Settings → Status to see the tools load. ([JetBrains]1)

---

If problems persist

• Try running with a short path with no spaces (e.g., move Node to C:\Node) due to an open Junie bug on Windows path handling. ([YouTrack]2)
• Update PhpStorm/Junie to the 2025.2 line or newer where a number of MCP integration fixes landed. ([JetBrains]6, [The JetBrains Blog]7)
• Grab Junie’s “Copy Stdio Config” (Manual Client Configuration) and compare the shape/fields against what you entered. ([JetBrains]8)

If you want, paste your exact mcp.json here (with the token redacted) and I’ll spot-check it for Windows gotchas.

[rolandorojas]

Yeah, I spent about an hour trying to debug it with GPT5. I tested a bunch of different things, but my original comment is as far as I got. I tried these suggestions, but they don't work either. I was hoping someone smarter than me would have the solution.

[brianr]

Dang, OK! Does seem like some issue related to how Junie is invoking node/npx.

[brianr]

@rolandorojas can you share the rollbar section of the mcpServers config you have for Junie? (redacting token of course but would like to see as much as possible of the details).

[rolandorojas]

Sure. Here it is:

{
    "mcpServers": {
        "rollbar": {
            "type": "stdio",
          "command": "C:\\nvm4w\\nodejs\\npx.cmd",
          "args": ["-y", "@rollbar/mcp-server@latest", "--stdio"],
            "env": {
                "ROLLBAR_ACCESS_TOKEN": "REDACTED"
            }
        }
    }
}

[brianr]

@rolandorojas , we've found there seem to be issues in general with Junie's MCP support (example), BUT that said, we (@TheDevFactory) were able to get it working on Windows 11, PHPStorm 2025.2, and Junie 252.284.66 by doing the following:

1. Clone this repo and build locally, as shown here: https://github.com/rollbar/rollbar-mcp-server/blob/main/CONTRIBUTING.md#how-to-develop
2. Configure as follows (note the forward slashes even though it's Windows):

"rollbar": {
  "type": "stdio",
  "command": "node",
  "args": [
    "C:/path/to/rollbar-mcp-server/build/index.js"
  ],
  "env": {
    "ROLLBAR_ACCESS_TOKEN": "redacted"
  }
}

Does this work for you?

[rolandorojas]

Thanks for that. I actually found that it was a completely different issue. When I ran it through the command line to debug, I got this;

Now, forget about the token error. The actual issue is that dotenv message. The server is not supposed to output anything until Junie connects. That dotenv message adds enough noise to make the connection break.

The way to fix it is simply to silence dotenv

 "rollbar": {
            "type": "stdio",
            "command": "C:\\nvm4w\\nodejs\\npx.cmd",
            "args": ["-y", "@rollbar/mcp-server@latest"],
            "env": {
                "ROLLBAR_ACCESS_TOKEN": "REDACTED",
                "DOTENV_CONFIG_QUIET": "true"
            }
        }

I think you could avoid having users do this if you do something like

require('dotenv').config({ quiet: true });

Thanks for the help!

[brianr]

@rolandorojas great find, thank you!

Fixed in #40 and will have that in the next release.

[brianr]

This fix has been released in 0.2.3. Thanks again!