# Optional API integration

Universal Document is an open format. No hosted API is required to create, open, or validate it.

Operational conversion and enterprise APIs are offered as managed services when their product status says Live or Early Access. Authentication, limits, and service-specific request/response contracts are supplied during onboarding; do not send credentials in URLs. Clients should treat 4xx errors as request/authentication failures, retry only retryable 5xx responses with backoff, and preserve the original input outside the service.

For independent implementation, use the public schema, profile, vectors, and local compatibility runner. Hosted services are convenience and scale layers, not ownership or control of the standard.