{"record":{"id":"a292b1d4b8027761","repo":"paperclipai/paperclip","slug":"mcp-sse-response-contained-no-data-events","errorCode":null,"errorMessage":"MCP SSE response contained no data events","messagePattern":"MCP SSE response contained no data events","errorType":"exception","errorClass":"SyntaxError","httpStatus":null,"severity":"error","filePath":"server/src/services/mcp-http.ts","lineNumber":83,"sourceCode":"    const data = dataLines.join(\"\\n\");\n    let parsed: unknown;\n    try {\n      parsed = JSON.parse(data) as unknown;\n    } catch (error) {\n      lastError = error;\n      continue;\n    }\n    if (!sawData) {\n      firstParsed = parsed;\n      sawData = true;\n    }\n    if (looksLikeJsonRpcMessage(parsed)) {\n      return parsed;\n    }\n  }\n  if (sawData) return firstParsed;\n  if (lastError) throw lastError;\n  throw new SyntaxError(\"MCP SSE response contained no data events\");\n}\n","sourceCodeStart":65,"sourceCodeEnd":85,"githubUrl":"https://github.com/paperclipai/paperclip/blob/120ae5428fa29bee300bcf806491cd4d965fbb7c/server/src/services/mcp-http.ts#L65-L85","documentation":"Protocol-shape failure in initializeMcpHttpSession's SSE reader: the HTTP stream from the MCP server produced SSE events but none carried data lines (and no earlier JSON parse succeeded). Thrown as a SyntaxError after all chunks are consumed, meaning the session could not be initialized from this response.","triggerScenarios":"Thrown at server/src/services/mcp-http.ts:83 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Check the MCP server SSE stream; ensure the server emits data events and the connection is not truncated."],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"120ae5428fa29bee300bcf806491cd4d965fbb7c","analyzedAt":"2026-08-18T22:49:45.177Z","contentChangedAt":"2026-08-18T22:49:45.177Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}