HTTP status codes
| Code | Description |
|---|---|
| 200 | Success |
| 201 | Created - Resource successfully created |
| 204 | No Content - Resource successfully deleted |
| 400 | Bad Request - Invalid request format (e.g. a timestamp missing an explicit UTC offset) |
| 401 | Unauthorized - Invalid or expired token |
| 403 | Forbidden - Insufficient permissions |
| 404 | Not Found - Resource does not exist |
| 409 | Conflict - Resource conflict (e.g., duplicate) |
| 422 | Unprocessable Entity - Valid format but fails business validation |
| 429 | Too Many Requests - Rate limit exceeded |
| 500 | Internal Server Error - Contact support |
Error response format
ProblemDetails Response: All error responses use the RFC 9457 (Problem Details for HTTP APIs) format with the following fields:| Field | Type | Description |
|---|---|---|
| type | string | URI reference identifying the problem type |
| title | string | Short, human-readable summary of the problem type |
| status | number | HTTP status code |
| detail | string | Human-readable explanation specific to this occurrence |
| instance | string | URI identifying the specific API instance |
| errors | object | Validation errors by field name (only for validation failures) |
| timestamp | string (ISO 8601) | When the error occurred in UTC |
| trace_id | string | Request identifier for tracing and correlation |
{
"type": "https://tools.ietf.org/html/rfc9110#section-15.5.23",
"title": "Unprocessable Content",
"status": 422,
"detail": "One or more validation errors occurred in the request.",
"instance": "/v1/nominations/supplier",
"errors": {
"ClientReference": ["The ClientReference field is required."],
"FuelSpecifications": ["At least one fuel specification is required."]
},
"timestamp": "2026-03-10T12:34:56Z",
"trace_id": "00-abc123-def456-00"
}
{
"type": "https://tools.ietf.org/html/rfc9110#section-15.5.1",
"title": "Bad Request",
"status": 400,
"detail": "The timestamp '2026-07-06T14:00:00' must include an explicit UTC offset, for example '2026-07-06T14:00:00+02:00', '2026-07-06T14:00:00-04:00', or '2026-07-06T14:00:00Z'.",
"instance": "/v1/nominations/supplier",
"timestamp": "2026-03-10T12:34:56Z",
"trace_id": "00-abc123-def456-00"
}
{
"type": "https://tools.ietf.org/html/rfc9110#section-15.5.5",
"title": "Not Found",
"status": 404,
"detail": "Nomination with client reference 'NOM-2025-999' was not found.",
"instance": "/v1/nominations/NOM-2025-999",
"timestamp": "2026-03-10T12:34:56Z",
"trace_id": "00-abc123-def456-00"
}
{
"type": "https://tools.ietf.org/html/rfc9110#section-15.6.1",
"title": "Internal Server Error",
"status": 500,
"detail": "An unexpected error occurred",
"instance": "/v1/nominations/supplier",
"timestamp": "2026-03-10T12:34:56Z",
"trace_id": "00-abc123-def456-00"
}