What is the WordPress REST API schema and how does defining it for a custom endpoint improve security?

Question

WordPress Expert — Medium

What is the WordPress REST API schema and how does defining it for a custom endpoint improve security?

Accepted Answer

Defining the WordPress REST API schema in register_rest_route() args ensures that parameters meet specific requirements before custom code executes, enhancing security by preventing invalid requests. WordPress automatically validates and sanitizes parameters against the schema, rejecting unauthorized requests with 400 errors.