XTLS/Xray-core · error

not trojan protocol

Error message

not trojan protocol

What it means

Error "not trojan protocol" thrown in XTLS/Xray-core.

Source

Thrown at proxy/trojan/server.go:178

	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{
			From:   conn.RemoteAddr(),
			To:     "",
			Status: log.AccessRejected,
			Reason: err,
		})

		shouldFallback = true
	} else {
		user = s.validator.Get(hexString(first.BytesTo(56)))
		if user == nil {
			// invalid user, let's fallback
			err = errors.New("not a valid user")
			log.Record(&log.AccessMessage{
				From:   conn.RemoteAddr(),
				To:     "",
				Status: log.AccessRejected,
				Reason: err,

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at proxy/trojan/server.go:178 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/85a799f4ab228709. Report an issue: GitHub.