Hermes and mcp

Setup, Configuration and Use Installation
1

I tried Hermes Agent with mcp and have no success to established the connection without issue. Get 400 error.
Tried opencode mcp and this is working without an issue. With same configuration with same openhab cloud url and API key.
Is there a special trick to solve this or is this an issue by Hermes?
Somebody out there who tried that?

2

Can you explain how you are trying to set this up? What values you are using, stdio vs direct vs cloud? Anything really?

Edit: Also does the 400 error have any other info in it, a message or something like that? Also i take it hermes is running locally? Or are you using something like a VPS?

EDIT 2: One last thing, just looking at hermes, are you specifying the bearer token for hermes specifically like:

mcp_servers:
  openhab:
    url: "http://openhab.local:8080/mcp" # or your https local url or https://myopenhab.org/api/hooks/<uuid>
    headers:
      Authorization: "Bearer oh.YOUR_TOKEN"

I have not yet run hermes (or claw or similar), so i’m not 100% sure. The good thing is we are using the official MCP java library, so should be very standards compliant.

3

Hi Dan,

thanks for your response and sorry for my late answer.

[hermes] WARNING tools.mcp_tool: Failed to connect to MCP server 'openhab': Client error '400 Bad Request' for url '``https://myopenhab.org/api/hooks/UUID``'
[hermes] For more information check: ``https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/400

And my config looks like:

mcp_servers:
openhab:
url: ``https://myopenhab.org/api/hooks/uuid
transport: streamable-http
headers:
Authorization: Bearer ${OPENHAB_API_KEY}
n8n:
url: ``http://192.168.0.50:5678/mcp-server/http
headers:
Authorization: Bearer ${N8N_API_KEY}
linear:
url: ``https://mcp.linear.app/mcp
auth: oauth
enabled: true

So MCP for n8n isn’t a problem it’s working but openhab doesn’t work. As i told before… Only in hermes. URL is working in opencode.

Dunno why formatting goes wrong here…