XTLS/Xray-core · error

failed to read first request

Error message

failed to read first request

What it means

Error "failed to read first request" thrown in XTLS/Xray-core.

Source

Thrown at proxy/trojan/server.go:161

// Network implements proxy.Inbound.Network().
func (s *Server) Network() []net.Network {
	return []net.Network{net.Network_TCP, net.Network_UNIX}
}

// Process implements proxy.Inbound.Process().
func (s *Server) Process(ctx context.Context, network net.Network, conn stat.Connection, dispatcher routing.Dispatcher) error {
	iConn := stat.TryUnwrapStatsConn(conn)

	sessionPolicy := s.policyManager.ForLevel(0)
	if err := conn.SetReadDeadline(time.Now().Add(sessionPolicy.Timeouts.Handshake)); err != nil {
		return errors.New("unable to set read deadline").Base(err).AtWarning()
	}

	first := buf.FromBytes(make([]byte, buf.Size))
	first.Clear()
	firstLen, err := first.ReadFrom(conn)
	if err != nil {
		return errors.New("failed to read first request").Base(err)
	}
	errors.LogInfo(ctx, "firstLen = ", firstLen)

	bufferedReader := &buf.BufferedReader{
		Reader: buf.NewReader(conn),
		Buffer: buf.MultiBuffer{first},
	}

	var user *protocol.MemoryUser

	napfb := s.fallbacks
	isfb := napfb != nil

	shouldFallback := false
	if firstLen < 58 || first.Byte(56) != '\r' {
		// invalid protocol
		err = errors.New("not trojan protocol")
		log.Record(&log.AccessMessage{

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at proxy/trojan/server.go:161 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/2917d5215cf7d875. Report an issue: GitHub.