Errors

Close codes

Code	Meaning	Do
`4000`	Idle: 60 s without a JSON ping or subscription change	Fix the heartbeat, then reconnect
`4008`	Connection reached 24 h	Reconnect
`4403`	API key revoked or expired	Get a valid API key; do not retry blindly
`1013`	Temporary: socket or airport cap overshoot, or a slow reader	Reconnect with backoff
`1008`	Reserved: bad path	Check the URL

See Close codes on the WebSocket API page.

On the WebSocket

Errors on an open socket are messages, and the socket stays open. Codes: invalid_airports, bad_request, unknown_action, too_many_airports. Other events close the socket with a close code instead, for example 4403 when an API key is revoked or expires. See Errors on the socket.

HTTP

502 and 504 are not used: MOBS answers from memory.

HTTP	Meaning
400	`invalid_airports`: an airport is not covered
401	Invalid or expired API key
403	API key lacks the scope
422	Bad query: malformed code, more than 100 codes, bad `mode`, or missing `airports`
429	Rate limit, with Retry-After
503	METAR not live yet after a start, or the server-wide cap

Bodies are JSON with error, message and, on 429 and a full-server 503, retry_after_s.

Placeholder · A11

{"error":"unauthorized",
 "message":"a valid API key is required"}

{"error":"forbidden",
 "message":"this API key does not have the stream scope"}

{"error":"rate_limited",
 "message":"too many connections for this API key",
 "retry_after_s":30}

These messages use the “API key” wording that shipped in v0.11.3, which is the current main. The 403 message names the missing scope (stream or latest), so the example above is the stream case.

Getting started

METAR API

Coverage

Close codes

On the WebSocket

HTTP

​Close codes

​On the WebSocket

​HTTP

Close codes

On the WebSocket

HTTP