Content-Type: application/problem+json. Inspect code for the category and detail for context. Preserve request_id when reporting a failure. Validation errors may include an errors object keyed by field.
Each endpoint lists the errors relevant to that operation. Unexpected server or infrastructure failures can have a different response body, so clients must handle HTTP errors even when the body is not problem JSON.
Respond to the error
These are shared recovery conventions, not a promise that every endpoint returns every status.
Rate limits
Request budgets are shared across credentials for a member and organization. A429 response includes Retry-After in seconds. Wait before retrying and use bounded backoff to avoid repeatedly exhausting the budget.
For a mutation, preserve the same idempotency key and body when retrying the same logical operation. Do not assume a timeout means the server did not apply the change. See writes and concurrency.