Adding custom MCP server via supergateway

[shillem]

I am trying to configure a n8n MPC server using Supergateway.

The command is the following: npx -y supergateway --sse [url_placeholder] --header 'Authorization: Bearer [bearer_placeholder]'

However nothing happens, the UI shows Installing but never completes.

The log shows the following:

[2025-05-29][13:53:45][Tome::mcp::process][INFO] Executing command: Command { std: "/Applications/Tome.app/Contents/Resources/npx" "-y" "-y" "supergateway" "--sse" "https://<REDACTED>" "--header" "\'Authorization:" "Bearer" "<REDACTED>\'", kill_on_drop: false } ["-y", "-y", "supergateway", "--sse", "<REDACTED>", "--header", "'Authorization:", "Bearer", "<REDACTED>'"]

The Tome.log:

[2025-05-29][21:21:29][hermit][DEBUG] npx -y -y supergateway --sse <REDACTED> --header 'Authorization: Bearer <REDACTED>'

If I run the command from terminal the server spins up just fine.

Also, is there a way to define the name of the MCP server?

[mnoble]

Okay, so I tried to reproduce this. I tried this with an, admittedly, silly setup – but I think it emulates things well enough to just test.

I started up mcp-server-git as an SSE server using supergateway to emulate your n8n SSE server:

npx -y supergateway --stdio "uvx mcp-server-git"

Then I added it to Tome, also using supergateway, but with sse ➞ stdio:

npx -y supergateway --sse http://localhost:8000/sse

And it resolved, updated the name in Tome, BUT it couldn't pull the list of tools. It bails out with a JSON parsing error:

[2025-05-30][20:05:19][rmcp::transport::io][ERROR] Error reading from stream: serde error data did not match any variant of untagged enum JsonRpcMessage

I'm not exactly sure what format that's coming back as, but serde (Rust json lib) can't parse the JSON.

I'll do some more digging when I get a chance, but I suspect supergateway is returning JSON in a different format than "normal" stdio servers do and that's why it's failing to parse.

[shillem]

@mnoble thank you for testing. It seems you are able to go a step further than I can. I can't see errors/warnings logged on my side 😅

[shillem]

OK, a little update. I was able to have the mcp server appear, and confirm the serde error logged. So that's an issue. The other issue, when it doesn't set up the MCP server is due to me passing the authorization header parameter not working. If I do it from my terminal the supergateway starts fine, but not from within Tome. If I remove the need for the Authorization Bearer header, then it gets correctly initialized in Tome (though it doesn't really work as that serde error is thrown).

[mnoble]

The serde error is because the response isn't matching any of these enum values from the mcp library we're using (https://github.com/modelcontextprotocol/rust-sdk/blob/main/crates/rmcp/src/model.rs#L456). Why that is, though, I'm unsure still. I haven't had time yet to investigate more, tbh, but I need to dump the raw JSON-RPC response and take a look.

I suspect I know what the auth header issue is, though. I wrote a very naive parser for the mcp commands that just splits on whitespace. So I think the command, in Rust, ends up being:

["npx", "-y", "supergateway", "--sse", "{url_placeholder}", "--header", "'Authorization:", "Bearer {bearer}'"]

Notice the 'Authorization:" and Bearer {bearer}'` being two distinct elements. That might be the issue, but it's just a hunch so ¯_(ツ)_/¯

[Nedomas]

Hi, you can use Supergateway’s --oauth2Bearer "some-access-token" flag to pass Authorization header to client that seem to cut up the --header flag incorrectly like it’s happening here (Cursor has the same bug).

So your command would be this:

npx -y supergateway --sse [url_placeholder] --oauth2Bearer [bearer_placeholder]

[shillem]

Thank you @Nedomas , the --oauth2Bearer approach is definitely easier and solves the issue!

[shillem]

@mnoble I inspected Claude's logs, which is able to load the tools from the MCP server. However I noticed some errors there that maybe could be relevant for you:

2025-06-10T15:03:04.837Z [n8n] [info] Message from client: {"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0}
[supergateway] Starting...
[supergateway] Supergateway is supported by Supermachine (hosted MCPs) - https://supermachine.ai
[supergateway]   - outputTransport: stdio
[supergateway] Connecting to SSE...
[supergateway] Stdio server listening
[supergateway] Stdio → SSE: {
  jsonrpc: '2.0',
  id: 0,
  method: 'initialize',
  params: {
    protocolVersion: '2024-11-05',
    capabilities: {},
    clientInfo: { name: 'claude-ai', version: '0.1.0' }
  }
}
[supergateway] SSE connected
[supergateway] Response: {
  jsonrpc: '2.0',
  id: 0,
  result: {
    protocolVersion: '2024-11-05',
    capabilities: { tools: {} },
    serverInfo: { name: 'n8n-mcp-server', version: '0.1.0' }
  }
}
2025-06-10T15:03:06.944Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":0,"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{}},"serverInfo":{"name":"n8n-mcp-server","version":"0.1.0"}}}
2025-06-10T15:03:06.945Z [n8n] [info] Message from client: {"method":"notifications/initialized","jsonrpc":"2.0"}
[supergateway] SSE → Stdio: { jsonrpc: '2.0', method: 'notifications/initialized' }
2025-06-10T15:03:06.946Z [n8n] [info] Message from server: {"jsonrpc":"2.0","method":"notifications/initialized"}
2025-06-10T15:03:06.946Z [n8n] [info] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":1}
2025-06-10T15:03:06.946Z [n8n] [info] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":2}
2025-06-10T15:03:06.946Z [n8n] [info] Message from client: {"method":"resources/list","params":{},"jsonrpc":"2.0","id":3}
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 1, method: 'tools/list', params: {} }
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 2, method: 'tools/list', params: {} }
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 3, method: 'resources/list', params: {} }
[supergateway] Response: {
  jsonrpc: '2.0',
  id: 1,
  result: { tools: [ [Object], [Object], [Object], [Object], [Object] ] }
}
2025-06-10T15:03:07.048Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":1,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
[supergateway] Response: {
  jsonrpc: '2.0',
  id: 2,
  result: { tools: [ [Object], [Object], [Object], [Object], [Object] ] }
}
2025-06-10T15:03:07.129Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":2,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
[supergateway] Request error: McpError: MCP error -32601: Method not found
    at Client._onresponse (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:212:27)
    at _transport.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:76:22)
    at _eventSource.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/client/sse.js:105:79)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:106:119
    at dispatchEvent (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:70:24)
    at parseLine (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:23:7)
    at Object.feed (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:18:7)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:95:46
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5) {
  code: -32601,
  data: undefined
}
2025-06-10T15:03:07.130Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":3,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:03:07.131Z [n8n] [info] Message from client: {"method":"prompts/list","params":{},"jsonrpc":"2.0","id":4}
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 4, method: 'prompts/list', params: {} }
[supergateway] Request error: McpError: MCP error -32601: Method not found
    at Client._onresponse (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:212:27)
    at _transport.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:76:22)
    at _eventSource.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/client/sse.js:105:79)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:106:119
    at dispatchEvent (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:70:24)
    at parseLine (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:23:7)
    at Object.feed (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:18:7)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:95:46
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5) {
  code: -32601,
  data: undefined
}
2025-06-10T15:03:07.215Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":4,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:03:08.694Z [n8n] [info] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":5}
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 5, method: 'tools/list', params: {} }
2025-06-10T15:03:08.694Z [n8n] [info] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":6}
2025-06-10T15:03:08.694Z [n8n] [info] Message from client: {"method":"resources/list","params":{},"jsonrpc":"2.0","id":7}
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 6, method: 'tools/list', params: {} }
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 7, method: 'resources/list', params: {} }
[supergateway] Response: {
  jsonrpc: '2.0',
  id: 5,
  result: { tools: [ [Object], [Object], [Object], [Object], [Object] ] }
}
[supergateway] Response: {
  jsonrpc: '2.0',
  id: 6,
  result: { tools: [ [Object], [Object], [Object], [Object], [Object] ] }
}
[supergateway] Request error: McpError: MCP error -32601: Method not found
    at Client._onresponse (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:212:27)
    at _transport.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:76:22)
    at _eventSource.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/client/sse.js:105:79)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:106:119
    at dispatchEvent (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:70:24)
    at parseLine (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:23:7)
    at Object.feed (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:18:7)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:95:46
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5) {
  code: -32601,
  data: undefined
}
2025-06-10T15:03:08.835Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":5,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
2025-06-10T15:03:08.849Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":6,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
2025-06-10T15:03:08.849Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":7,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:03:08.852Z [n8n] [info] Message from client: {"method":"prompts/list","params":{},"jsonrpc":"2.0","id":8}
[supergateway] Stdio → SSE: { jsonrpc: '2.0', id: 8, method: 'prompts/list', params: {} }
[supergateway] Request error: McpError: MCP error -32601: Method not found
    at Client._onresponse (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:212:27)
    at _transport.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:76:22)
    at _eventSource.onmessage (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/@modelcontextprotocol/sdk/dist/esm/client/sse.js:105:79)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:106:119
    at dispatchEvent (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:70:24)
    at parseLine (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:23:7)
    at Object.feed (file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource-parser/dist/index.js:18:7)
    at file:///Users/shillem/.npm/_npx/85d60ba1adc82a16/node_modules/eventsource/dist/index.js:95:46
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5) {
  code: -32601,
  data: undefined
}
2025-06-10T15:03:09.182Z [n8n] [info] Message from server: {"jsonrpc":"2.0","id":8,"error":{"code":-32601,"message":"Method not found"}}

And also

2025-06-10T15:03:04.811Z [info] [n8n] Initializing server...
2025-06-10T15:03:04.832Z [info] [n8n] Server started and connected successfully
2025-06-10T15:03:04.837Z [info] [n8n] Message from client: {"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0}
2025-06-10T15:03:06.945Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":0,"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{}},"serverInfo":{"name":"n8n-mcp-server","version":"0.1.0"}}}
2025-06-10T15:03:06.945Z [info] [n8n] Message from client: {"method":"notifications/initialized","jsonrpc":"2.0"}
2025-06-10T15:03:06.946Z [info] [n8n] Message from server: {"jsonrpc":"2.0","method":"notifications/initialized"}
2025-06-10T15:03:06.946Z [info] [n8n] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":1}
2025-06-10T15:03:06.946Z [info] [n8n] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":2}
2025-06-10T15:03:06.946Z [info] [n8n] Message from client: {"method":"resources/list","params":{},"jsonrpc":"2.0","id":3}
2025-06-10T15:03:07.048Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":1,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
2025-06-10T15:03:07.129Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":2,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
2025-06-10T15:03:07.130Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":3,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:03:07.131Z [info] [n8n] Message from client: {"method":"prompts/list","params":{},"jsonrpc":"2.0","id":4}
2025-06-10T15:03:07.215Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":4,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:03:08.694Z [info] [n8n] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":5}
2025-06-10T15:03:08.694Z [info] [n8n] Message from client: {"method":"tools/list","params":{},"jsonrpc":"2.0","id":6}
2025-06-10T15:03:08.694Z [info] [n8n] Message from client: {"method":"resources/list","params":{},"jsonrpc":"2.0","id":7}
2025-06-10T15:03:08.835Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":5,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
2025-06-10T15:03:08.849Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":6,"result":{"tools":[{"name":"MCP_Brave_List_Tools","description":"Use MCP client","inputSchema":{"type":"object","properties":{},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"MCP_Brave_Execute_Tool","description":"Use MCP client","inputSchema":{"type":"object","properties":{"tool":{"type":"string","description":"Set this with the specific MCP Brave tool name"},"Tool_Parameters":{}},"required":["tool","Tool_Parameters"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"qdrant","description":"It contains scraped websites contents","inputSchema":{"type":"object","properties":{"input":{"type":"string"}},"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"IPinfo","description":"It returns information associated with a given IP address.","inputSchema":{"type":"object","properties":{"ipAddress":{"type":"string"}},"required":["ipAddress"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}},{"name":"UptimeRobot","description":"Get many monitors in UptimeRobot","inputSchema":{"type":"object","properties":{"Search":{"type":"string"}},"required":["Search"],"additionalProperties":true,"$schema":"http://json-schema.org/draft-07/schema#"}}]}}
2025-06-10T15:03:08.849Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":7,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:03:08.853Z [info] [n8n] Message from client: {"method":"prompts/list","params":{},"jsonrpc":"2.0","id":8}
2025-06-10T15:03:09.182Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":8,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:13:09.384Z [info] [n8n] Message from client: {"method":"resources/list","params":{},"jsonrpc":"2.0","id":9}
2025-06-10T15:13:09.630Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":9,"error":{"code":-32601,"message":"Method not found"}}
2025-06-10T15:13:09.630Z [info] [n8n] Message from client: {"method":"prompts/list","params":{},"jsonrpc":"2.0","id":10}
2025-06-10T15:13:09.804Z [info] [n8n] Message from server: {"jsonrpc":"2.0","id":10,"error":{"code":-32601,"message":"Method not found"}}

Could the error be related to what is discussed on this supergateway issue: supercorp-ai/supergateway#12

[Nedomas]

hey @shillem - these errors MCP error -32601: Method not found are expected as this is just how MCP clients warn when the MCP server does not provide some of the MCP features - in this case prompts/list and such.

Since the underlying server you’re wrapping with Supergateway does not have prompts, it will correctly error on these requests. But it is not a problem and you can treat them more as warnings rather than errors.