mcp tools not working with springboot ai 1.1.0-M1

[jbrinnand]

springboot ai 1.1.0-M1 is a new version of springboot ai and uses McpTool annotation instead of Tool to annotate methods. It looks like mcp tools is not able to read the tools when this annotation is present.

For example:

Accessing the server on the command line:

`mcp tools http://localhost:8898/mcp

Error: unexpected status code: 400

Example: mcp tools npx -y @modelcontextprotocol/server-filesystem ~`

However the npx inspector can access the server and run the tools successfully

So - why does mcp tools not work but the npx inspector connects and runs the tools successfully?

Thanks in advance

[esnible]

I had a similar problem. Wireshark revealed that the server provided more details that were not included in the CLI response: {"jsonrpc":"2.0","id":"server-error","error":{"code":-32600,"message":"Bad Request: Missing session ID"}}

The mcptools client starts with something like

GET /mcp HTTP/1.1
Host: server2.127-0-0-1.sslip.io:8888
User-Agent: Go-http-client/1.1
Accept: text/event-stream
Cache-Control: no-cache
Connection: keep-alive
Accept-Encoding: gzip

With recent libraries, protocolVersion: "2025-03-26", there should be a POST first to get the session ID.

[nilzao]

same here, with curl to debug:

get Mcp-Session-Id: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

curl -v --location 'http://localhost:8080/mcp' \
--header 'Accept: application/json, text/event-stream' \
--header 'Content-Type: application/json' \
--data '{
    "jsonrpc": "2.0",
    "method": "initialize",
    "id": "random-id-1234",
    "params": {
        "protocolVersion": "2025-06-18",
        "capabilities": {},
        "clientInfo": {
            "name": "My curl hack",
            "version": "0.0.1"
        }
    }
}'

curl --location 'http://localhost:8080/mcp' \
--header 'Accept: application/json, text/event-stream' \
--header 'mcp-session-id: 32fb52e1-1ee9-4af7-8b8d-39956f99613f' \
--header 'Content-Type: application/json' \
--data '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/list" 
}'

[nilzao]

hello world to test https://github.com/k3s-ia-lab/mcp-playground