cloudflare/cloudflared · error

invalid message type was provided

Error message

invalid message type was provided

What it means

Package-level sentinel error (errInvalidMessageType) in the management protocol. ReadServerEvent/ReadClientEvent return it when a decoded event's type is the zero value (UnknownServerEventType/UnknownClientEventType), meaning the peer sent a JSON message with a missing or empty 'type' field — a generic guard against malformed protocol messages.

Source

Thrown at management/events.go:15

package management

import (
	"context"
	"errors"
	"fmt"
	"io"

	jsoniter "github.com/json-iterator/go"
	"github.com/rs/zerolog"
	"nhooyr.io/websocket"
)

var (
	errInvalidMessageType = fmt.Errorf("invalid message type was provided")
)

// ServerEventType represents the event types that can come from the server
type ServerEventType string

// ClientEventType represents the event types that can come from the client
type ClientEventType string

const (
	UnknownClientEventType ClientEventType = ""
	StartStreaming         ClientEventType = "start_streaming"
	StopStreaming          ClientEventType = "stop_streaming"

	UnknownServerEventType ServerEventType = ""
	Logs                   ServerEventType = "logs"
)

// ServerEvent is the base struct that informs, based of the Type field, which Event type was provided from the server.

View on GitHub (pinned to 2253eeeb25)

Solutions

1. Inspect the websocket message received; its 'type' field is empty or absent.
2. Callers should compare with errors.Is(err, management.ErrInvalidMessageType) to distinguish it from typed unknown-type errors.
3. Fix the peer/sender to always set a valid event type, or ignore malformed messages in streaming loops.

When it happens

Trigger: Thrown at management/events.go:15 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of cloudflare/cloudflared@2253eeeb25 (2026-09-06). Data as JSON: /api/errors/9b932ab57709e010. Report an issue: GitHub.