Errors

Errors return a JSON body with a detail message and a standard HTTP status:

{ "detail": "Requires plan: pro or enterprise" }

Status	Meaning
400	Bad request / validation error
401	Not authenticated (missing/invalid key or session)
402	Plan required — the feature isn't on your plan
403	Authenticated but not permitted (scope/role)
404	Resource not found
409	Conflict (e.g. alias already taken)
410	Gone (expired / exhausted link)
422	Unprocessable (e.g. destination flagged unsafe)
429	Rate limited — see Rate limits
5xx	Server error — safe to retry with backoff

Validation errors (400/422) may return a list of field issues; render detail accordingly.