{"record":{"id":"6d9fa3a3e12ccc70","repo":"langflow-ai/langflow","slug":"internal-server-error-in-project-mcp-transport","errorCode":null,"errorMessage":"Internal server error in project MCP transport","messagePattern":"Internal server error in project MCP transport","errorType":"http","errorClass":"HTTPException","httpStatus":500,"severity":"error","filePath":"src/backend/base/langflow/api/v1/mcp_projects.py","lineNumber":530,"sourceCode":") -> Response:\n    \"\"\"Common handler for project-specific Streamable HTTP requests.\"\"\"\n    # Lazily initialize the project's Streamable HTTP manager\n    # to pick up new projects as they are created.\n    project_server = get_project_mcp_server(project_id)\n    await project_server.ensure_session_manager_running()\n\n    user_token = current_user_ctx.set(current_user)\n    project_token = current_project_ctx.set(project_id)\n    variables = extract_global_variables_from_headers(request.headers, include_auth_headers=True)\n    request_vars_token = current_request_variables_ctx.set(variables or None)\n\n    try:\n        await project_server.session_manager.handle_request(request.scope, request.receive, request._send)  # noqa: SLF001\n    except HTTPException:\n        raise\n    except Exception as exc:\n        await logger.aexception(f\"Error handling Streamable HTTP request for project {project_id}: {exc!s}\")\n        raise HTTPException(status_code=500, detail=\"Internal server error in project MCP transport\") from exc\n    finally:\n        current_request_variables_ctx.reset(request_vars_token)\n        current_project_ctx.reset(project_token)\n        current_user_ctx.reset(user_token)\n\n    return ResponseNoOp(status_code=200)\n\n\nstreamable_http_route_config = {\n    \"methods\": [\"GET\", \"POST\", \"DELETE\"],\n    \"response_class\": ResponseNoOp,\n    \"include_in_schema\": False,\n}\n\n\n@router.api_route(\"/{project_id}/streamable\", **streamable_http_route_config)\n@router.api_route(\"/{project_id}/streamable/\", **streamable_http_route_config)\nasync def handle_project_streamable_http(","sourceCodeStart":512,"sourceCodeEnd":548,"githubUrl":"https://github.com/langflow-ai/langflow/blob/976ec789d2886a86de109c044d089d68e96c9a35/src/backend/base/langflow/api/v1/mcp_projects.py#L512-L548","documentation":"Error \"Internal server error in project MCP transport\" thrown in langflow-ai/langflow.","triggerScenarios":"Occurs when an unexpected internal error is raised inside the project MCP transport handler.","commonSituations":"See trigger scenarios.","solutions":["Check server logs for the transport error and retry; restart the MCP server if it is stuck."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"976ec789d2886a86de109c044d089d68e96c9a35","analyzedAt":"2026-08-14T18:23:12.227Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}