{"record":{"id":"34f325109c6728f2","repo":"zeroclaw-labs/zeroclaw","slug":"mcp-server-returned-no-response","errorCode":null,"errorMessage":"MCP server returned no response","messagePattern":"MCP server returned no response","errorType":"exception","errorClass":"anyhow::Error","httpStatus":null,"severity":"error","filePath":"crates/zeroclaw-tools/src/mcp_transport.rs","lineNumber":1653,"sourceCode":"        last_event_data_lines = current_data_lines;\n    }\n\n    if last_event_data_lines.is_empty() {\n        return Cow::Borrowed(text.trim());\n    }\n\n    if last_event_data_lines.len() == 1 {\n        return Cow::Borrowed(last_event_data_lines[0].trim());\n    }\n\n    let joined = last_event_data_lines.join(\"\\n\");\n    Cow::Owned(joined.trim().to_string())\n}\n\nfn parse_jsonrpc_response_text(resp_text: &str) -> Result<JsonRpcResponse> {\n    let trimmed = resp_text.trim();\n    if trimmed.is_empty() {\n        bail!(\"MCP server returned no response\");\n    }\n\n    let json_text = if looks_like_sse_text(trimmed) {\n        extract_json_from_sse_text(trimmed)\n    } else {\n        Cow::Borrowed(trimmed)\n    };\n\n    let mcp_resp: JsonRpcResponse = serde_json::from_str(json_text.as_ref())\n        .with_context(|| format!(\"invalid JSON-RPC response: {}\", resp_text))?;\n    Ok(mcp_resp)\n}\n\nfn looks_like_sse_text(text: &str) -> bool {\n    text.starts_with(\"data:\")\n        || text.starts_with(\"event:\")\n        || text.contains(\"\\ndata:\")\n        || text.contains(\"\\nevent:\")","sourceCodeStart":1635,"sourceCodeEnd":1671,"githubUrl":"https://github.com/zeroclaw-labs/zeroclaw/blob/88bb9c8533fc57ed7a03e36ca7c9ed2bf8336dcc/crates/zeroclaw-tools/src/mcp_transport.rs#L1635-L1671","documentation":"Error \"MCP server returned no response\" thrown in zeroclaw-labs/zeroclaw.","triggerScenarios":"Thrown at crates/zeroclaw-tools/src/mcp_transport.rs:1653 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Check the MCP server is responding; verify transport health and retry."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"88bb9c8533fc57ed7a03e36ca7c9ed2bf8336dcc","analyzedAt":"2026-08-23T01:07:41.857Z","schemaVersion":2},"datasetVersion":"2026-08-23T08:06:27.607Z"}