WebSocket Close Code Lookup

Normal closure

The connection closed normally. Both sides agreed to close.

Recovery: No action needed. This is a clean close.

Going away

Server or client is going away (e.g., server shutdown, browser navigating away).

Recovery: Reconnect with exponential backoff. Check if the server is undergoing maintenance.

Protocol error

The endpoint received malformed data that violates the WebSocket protocol.

Recovery: Verify message framing and data format. Check for binary/text frame mismatches.

Unsupported data

The endpoint received data type it cannot handle (e.g., binary on a text-only endpoint).

Recovery: Ensure your messages match the expected data type (binary vs text).

No status received

Connection closed without sending a close frame.

Recovery: Treat as unexpected disconnection. Reconnect with backoff. Log the event.

Abnormal closure

Connection closed abnormally without a close frame. Common in trading bot WebSocket drops.

Recovery: This is the most common WebSocket error in trading bots. Reconnect with backoff and check for rate limiting on the endpoint.

Invalid frame payload data

The message payload is invalid (e.g., invalid UTF-8).

Recovery: Validate message encoding before sending. Ensure JSON is well-formed.

Policy violation

Connection rejected due to policy violation (e.g., rate limit exceeded).

Recovery: Check exchange rate limits. Reduce request frequency. Implement proper throttling.

Message too big

The message exceeds the maximum allowed frame size.

Recovery: Reduce message size or split large payloads into smaller chunks.

Internal server error

Server encountered an unexpected condition.

Recovery: Wait and retry with backoff. Check exchange status page for ongoing incidents.

Service restart

Server is restarting. Common during exchange maintenance windows.

Recovery: Reconnect after a delay. Check exchange maintenance schedule.

Try again later

Server is temporarily overloaded. Common during high volatility.

Recovery: Wait and retry with exponential backoff. Reduce connection frequency.

Application reserved

Exchange-specific close code. Refer to exchange WebSocket documentation.

Recovery: Check the exchange-specific WebSocket documentation for the exact meaning.

Rate limited

Connection rejected due to rate limiting on the WebSocket endpoint.

Recovery: Reduce reconnection frequency. Implement exponential backoff with jitter.

Invalid auth

Authentication failed for private WebSocket channels.

Recovery: Verify API key and signature. Regenerate credentials if needed.