br-write-schema

You can validate API payloads by defining a writeSchema on your WordPress Resource to apply per-field constraints, type coercion, and sanitization before handlers run. This ensures incoming data is checked and errors are reported as fieldErrors in a 400 response.

The best way to enforce per-field constraints on POST and PUT requests is to use a schema definition that checks required fields, nullable handling, and min/max length constraints. This approach validates and coerces payload data before it reaches your handlers.

When payload validation fails, the schema throws an ApiException with the code validation_failed. The system then returns a 400 HTTP response that includes details in the fieldErrors object, identifying the specific fields that did not meet the constraints.

Yes, you can reuse validation schemas across multiple WordPress Resource endpoints by defining them via writeSchema or payloadSchema. This allows consistent payload validation and sanitization across different resources without duplicating rule definitions.

Yes, payload schema validation supports a flat enum shape with an explicit values list and provides aliases for common types like int for integer and bool for boolean. This simplifies schema definitions while maintaining strict constraint checks.