N8n new instance-level MCP not working with Gemini CLI?

Questions
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Describe the problem/error/question

It might be a Gemini CLI problem, but I’m not able to use n8n’s new instance-level MCP feature. gemini mcp list shows it connected correctly as streamable-http, and I managed to send a simple tools/list request to n8n and verified the MCP is indeed working. I am using the Authentication token method. Gemini CLI shows this error on interactive chat:

ℹ Restarting MCP servers…✕ MCP ERROR (n8n-instance)

✕ Error during discovery for MCP server ‘n8n-instance’: Client is not connected, must connect before interacting with the server. Current state is disconnected

What is the error message (if any)?

n8n doesnt show any errors its on Gemini CLI side which I described above. I am wondering if anyone managed to connect the new feature to Gemini CLI.

Please share your workflow

(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)

Share the output returned by the last node

Information on your n8n setup

  • n8n version: latest (2.3.2)
  • Database (default: SQLite): default
  • n8n EXECUTIONS_PROCESS setting (default: own, main): default
  • Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
  • Operating system: Ubuntu
  • Gemini CLI Version: 0.25.0-nightly.20260112.15891721a
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so the gemini cli might be having issues with the streamable-http transport that n8n uses for MCP. from what i’ve seen, some MCP clients expect stdio transport instead and dont handle http-based servers well yet.

couple things to try:

1. check your gemini cli config - make sure the n8n MCP server URL and auth token are exactly right

2. test the connection manually with curl to verify n8n’s MCP endpoint is actually accessible:

```bash

curl -H “Authorization: Bearer YOUR_TOKEN” http://your-n8n-instance/api/v1/mcp

```

3. gemini cli might need specific config for http-based MCP servers - check their docs or try a different MCP client like Claude Desktop to verify n8n’s side is working

the “must connect before interacting” error usually means the initial handshake failed, could be auth or the transport mismatch. lmk what you find with the curl test