XTLS/Xray-core · error

failed to write request header

Error message

failed to write request header

What it means

Error "failed to write request header" thrown in XTLS/Xray-core.

Source

Thrown at proxy/vless/encoding/encoding.go:57

		return errors.New("failed to write request user id").Base(err)
	}

	if err := EncodeHeaderAddons(&buffer, requestAddons); err != nil {
		return errors.New("failed to encode request header addons").Base(err)
	}

	if err := buffer.WriteByte(byte(request.Command)); err != nil {
		return errors.New("failed to write request command").Base(err)
	}

	if request.Command != protocol.RequestCommandMux && request.Command != protocol.RequestCommandRvs {
		if err := addrParser.WriteAddressPort(&buffer, request.Address, request.Port); err != nil {
			return errors.New("failed to write request address and port").Base(err)
		}
	}

	if _, err := writer.Write(buffer.Bytes()); err != nil {
		return errors.New("failed to write request header").Base(err)
	}

	return nil
}

// DecodeRequestHeader decodes and returns (if successful) a RequestHeader from an input stream.
func DecodeRequestHeader(isfb bool, first *buf.Buffer, reader io.Reader, validator vless.Validator) ([]byte, *protocol.RequestHeader, *Addons, bool, error) {
	buffer := buf.StackNew()
	defer buffer.Release()

	request := new(protocol.RequestHeader)

	if isfb {
		request.Version = first.Byte(0)
	} else {
		if _, err := buffer.ReadFullFrom(reader, 1); err != nil {
			return nil, nil, nil, false, errors.New("failed to read request version").Base(err)
		}

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at proxy/vless/encoding/encoding.go:57 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/1a04d0a62fd9e70f. Report an issue: GitHub.