Errors

The Brave gateway uses standard HTTP codes. The OS-Travel and Cyberesa compatible gateways always answer HTTP 200 and carry the error in the body — read all three sections.

Brave gateway — HTTP codes

Code	Typical `error.code`	Meaning
`400`	`validation_failed`	Invalid body or parameters (details in `error.fields`)
`401`	`invalid_signature`, `stale_timestamp`, `missing_credentials`	Authentication failed — see Request signing
`403`	`ip_not_allowed`, `key_revoked`, `gateway_not_enabled`	IP not allowed, key revoked, gateway or format not enabled
`404`	`not_found`	Unknown hotel, booking or reference data
`409`	`invalid_state`	State conflict (e.g. cancelling an already cancelled booking)
`422`	`rate_expired`, `stop_sales`, `on_request_only`	Offer expired, stop-sales, or “on request” offer not bookable
`429`	`rate_limited`	Quota exceeded — the `Retry-After` header says when to retry
`500`	`internal_error`	Internal error — retryable for reads only

Brave gateway — error envelope

JSON (Accept: application/json):

{
  "error": {
    "code": "rate_expired",
    "message": "The rate has expired. Run a new search.",
    "fields": { "rateKey": "expired on 2026-11-13T10:22:00+01:00" }
  }
}

XML (Accept: application/xml):

<ErrorResponse>
  <Code>rate_expired</Code>
  <Message>The rate has expired. Run a new search.</Message>
</ErrorResponse>

OS-Travel gateway — `ErrorMessage`

Always HTTP 200, even on errors: V1/V2 clients only parse 200.

{
  "ErrorMessage": {
    "Code": 401,
    "Description": "Invalid credentials."
  }
}

On success, ErrorMessage is always present with Code: null and Description: null (V2).
Quota exceeded: Description contains "Too many requests ... Retry after YYYY-MM-DD HH:MM:SS.".
For BookingCancellation, read the error in BookingCancellation.ErrorMessage (Code ≠ 200).

Cyberesa gateway — `ErrorResult`

Always HTTP 200 + valid XML, no CDATA. Business errors appear as:

<ErrorResult>
  <Message>Invalid credentials</Message>
</ErrorResult>

or <Error><Message>…</Message></Error>, or <Error>…</Error>. Check for these nodes before parsing the business response.

What to do

429 — respect Retry-After and slow down; see Rate limits.
401 — check the signature computation and clock sync (NTP).
422 rate_expired — the rateKey is gone: new search, new checkrate.
Bookings — never retry blindly: replay with the same clientReference (see Idempotency).
Reads — a single retry is fine (GET, search) on 500 or timeout.