API reference

Conventions

These conventions are shared with the HOPE Metahuman Service API and apply to every MTP endpoint, present and future.

Response envelopes

Successful REST responses are plain JSON resource representations.

Errors always use a single consistent shape:

{
  "error": {
    "code": "NOT_FOUND",
    "message": "The requested resource was not found",
    "requestId": "7f3a91c2-e8b4-4d21-9c65-0a3e8f1b47d2"
  }
}

requestId correlates your failure with the service’s logs. Capture it and include it in support requests.

Cross-tenant resource identifiers answer 404, never 403 — the API does not confirm the existence of resources you cannot access.

Common pagination

List routes that accept take and skip return an items array and total. take is capped by the endpoint, commonly at 100. Use the returned total rather than assuming a short page means there can be no later results.

{
  "items": [{ "...": "..." }],
  "total": 342
}

Timestamps

ISO 8601 in UTC, always: 2026-08-27T12:00:00.000Z.

Length limits

Every string field is capped. Exceeding a cap is a validation failure, not a truncation — the request is rejected. Limits will be listed per field on each endpoint page.

Strictness

Request bodies are validated strictly. An unrecognized field causes rejection rather than being silently ignored. This catches typos in field names, which would otherwise present as a setting mysteriously having no effect.

In the meantime

The concepts the API will expose are already documented: the content kernel describes the document model behind every content endpoint, roles and permissions the authorization model, and training sessions the runtime contract.