{"record":{"id":"6d4a0b4de4548fc3","repo":"n8n-io/n8n","slug":"method-not-allowed","errorCode":null,"errorMessage":"Method Not Allowed","messagePattern":"Method Not Allowed","errorType":"http","errorClass":null,"httpStatus":405,"severity":"error","filePath":"packages/@n8n/nodes-langchain/nodes/mcp/McpTrigger/McpServer.ts","lineNumber":273,"sourceCode":"\n\tasync handleDeleteRequest(req: express.Request, resp: CompressionResponse): Promise<void> {\n\t\tconst sessionId = this.getSessionId(req);\n\n\t\tif (!sessionId) {\n\t\t\tresp.status(400).send('No sessionId provided');\n\t\t\treturn;\n\t\t}\n\n\t\tconst transport = this.sessionManager.getTransport(sessionId);\n\n\t\tif (transport) {\n\t\t\tthis.pendingCallsManager.cleanupBySessionId(sessionId);\n\n\t\t\tif (transport instanceof StreamableHttpTransport) {\n\t\t\t\tawait transport.handleRequest(req, resp);\n\t\t\t\treturn;\n\t\t\t}\n\t\t\tresp.status(405).send('Method Not Allowed');\n\t\t\treturn;\n\t\t}\n\n\t\tresp.status(404).send('Session not found');\n\t}\n\n\tgetSessionId(req: express.Request): string | undefined {\n\t\treturn (req.query.sessionId ?? req.headers['mcp-session-id']) as string | undefined;\n\t}\n\n\tgetMcpMetadata(req: express.Request): { sessionId: string; messageId: string } | undefined {\n\t\tconst sessionId = this.getSessionId(req);\n\t\tif (!sessionId) return undefined;\n\n\t\tconst message = jsonParse(req.rawBody.toString());\n\t\tconst messageId = MessageParser.getRequestId(message);\n\n\t\treturn { sessionId, messageId: messageId ?? '' };","sourceCodeStart":255,"sourceCodeEnd":291,"githubUrl":"https://github.com/n8n-io/n8n/blob/5ac6606e81f67bb9534255570cd4e86fd8101eee/packages/@n8n/nodes-langchain/nodes/mcp/McpTrigger/McpServer.ts#L255-L291","documentation":"Error \"Method Not Allowed\" thrown in n8n-io/n8n.","triggerScenarios":"Thrown at packages/@n8n/nodes-langchain/nodes/mcp/McpTrigger/McpServer.ts:273 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"5ac6606e81f67bb9534255570cd4e86fd8101eee","analyzedAt":"2026-08-12T05:26:35.080Z","schemaVersion":2},"datasetVersion":"2026-08-12T13:17:24.610Z"}