SSE mode not working?

[sjoeboo]

Trying to spin this up locally, building/runnign via Docker:

FROM golang:1.24-alpine AS builder

WORKDIR /app

RUN GOBIN="/go/bin" go install github.com/grafana/mcp-grafana/cmd/mcp-grafana@latest

EXPOSE 8000

ENV GRAFANA_URL="http://grafana:3000"

ENTRYPOINT [ "/go/bin/mcp-grafana", "-sse-address", "0.0.0.0:8000", "-t", "sse" ]

the server comes up, but i can't connect to it (trying via Cursor, but also curling localhost:8000 just gets me 404's/not found. Is there is a specific path needed?

[sjoeboo]

okay, now i see it listens on localhost:8000/sse as i can curl that and get back

event: endpoint
data: http://0.0.0.0:8000/message?sessionId=93a03023-741e-4e67-82c6-a532cac9c40b

but am still not able to wire up cursor to this

[sd2k]

Hey @sjoeboo. After curling the /sse endpoint and starting the SSE connection, could you try running this in a separate terminal (replacing the session ID with whatever the first request echos):

curl "http://0.0.0.0:8000/message?sessionId=$SESSION_ID" -d '{"jsonrpc": "2.0", "id": 1, "method": "initialize", "params": {"protocolVersion": "", "capabilities": {}, "clientInfo": {"name": "mcp-golang-test", "version": "0.1.2"}}}'

[sjoeboo]

{"jsonrpc":"2.0","id":1,"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{}},"serverInfo":{"name":"mcp-grafana","version":"0.1.0"}}}

[sd2k]

Thanks, that's helpful, it looks like the server is up OK but we're printing a different address (0.0.0.0:8000) in the initial SSE event to what you have configured (localhost:8000).

As a workaround could you try changing your Cursor config to use 0.0.0.0:8000 instead? That seems to work for me (on Linux). And I'll look into adding a flag to customise the endpoint address.

[sjoeboo]

wow that did it, thanks for the quick help!

[sd2k]

I think tools may also fail for another reason I hadn't thought of: we don't use the GRAFANA_URL environment variable with the SSE transport. I'll push a new release to fix that soon!

[sjoeboo]

was. just encountering/finding that. Yeah being able to get the url/token from the env would be wonderful, thanks!

[sd2k]

v0.2.1 is released and should have fixes for all the above. Thanks for reporting!