Error catalog

Every error response uses the application/problem+json (RFC 9457) format. The type field points to the catalog page for its code: https://docs.skipo.com/errors/{code}. The code is a stable contract — branch your logic on it.

code	HTTP	Retryable?	Title
validation_error	400	no	Validation error
unauthorized	401	no	Unauthorized
invalid_signature	401	no	Invalid signature
clock_skew	401	yes	Clock skew too large
nonce_reused	401	yes	Nonce already used
key_expired	401	no	API key expired
key_revoked	401	no	API key revoked
insufficient_scope	403	no	Insufficient scope
ip_not_allowed	403	no	IP address not allowed
two_factor_required	403	no	Two-factor required
permission_denied	403	no	Permission denied
api_access_disabled	403	no	API access disabled
not_found	404	no	Resource not found
conflict	409	no	Conflict
idempotency_conflict	409	no	Idempotency conflict
key_limit_reached	409	no	API key limit reached
quotation_expired	410	yes	Quotation expired
unprocessable	422	no	Unprocessable request
rate_limited	429	yes	Rate limit exceeded
internal_error	500	yes	Internal server error
downstream_unavailable	502	yes	Downstream service unavailable
maintenance	503	yes	Service under maintenance
service_degraded	503	yes	Service degraded