{"record":{"id":"ea1196055f5a67b0","repo":"XTLS/Xray-core","slug":"failed-to-write-response-header","errorCode":null,"errorMessage":"failed to write response header","messagePattern":"failed to write response header","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"proxy/vless/encoding/encoding.go","lineNumber":148,"sourceCode":"\t\treturn nil, nil, nil, isfb, errors.New(\"invalid request version\")\n\t}\n}\n\n// EncodeResponseHeader writes encoded response header into the given writer.\nfunc EncodeResponseHeader(writer io.Writer, request *protocol.RequestHeader, responseAddons *Addons) error {\n\tbuffer := buf.StackNew()\n\tdefer buffer.Release()\n\n\tif err := buffer.WriteByte(request.Version); err != nil {\n\t\treturn errors.New(\"failed to write response version\").Base(err)\n\t}\n\n\tif err := EncodeHeaderAddons(&buffer, responseAddons); err != nil {\n\t\treturn errors.New(\"failed to encode response header addons\").Base(err)\n\t}\n\n\tif _, err := writer.Write(buffer.Bytes()); err != nil {\n\t\treturn errors.New(\"failed to write response header\").Base(err)\n\t}\n\n\treturn nil\n}\n\n// DecodeResponseHeader decodes and returns (if successful) a ResponseHeader from an input stream.\nfunc DecodeResponseHeader(reader io.Reader, request *protocol.RequestHeader) (*Addons, error) {\n\tbuffer := buf.StackNew()\n\tdefer buffer.Release()\n\n\tif _, err := buffer.ReadFullFrom(reader, 1); err != nil {\n\t\treturn nil, errors.New(\"failed to read response version\").Base(err)\n\t}\n\n\tif buffer.Byte(0) != request.Version {\n\t\treturn nil, errors.New(\"unexpected response version. Expecting \", int(request.Version), \" but actually \", int(buffer.Byte(0)))\n\t}\n","sourceCodeStart":130,"sourceCodeEnd":166,"githubUrl":"https://github.com/XTLS/Xray-core/blob/7d214f8b094f75322fa3990f8aadad1c912f24f5/proxy/vless/encoding/encoding.go#L130-L166","documentation":"Error \"failed to write response header\" thrown in XTLS/Xray-core.","triggerScenarios":"Thrown at proxy/vless/encoding/encoding.go:148 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":"7d214f8b094f75322fa3990f8aadad1c912f24f5","analyzedAt":"2026-08-15T14:26:24.325Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}