New to REST APIs? Get up to speed with phrases used throughout our documentation.
Model-View-Controller is a standard pattern in software development. If you aren’t already familiar with it, you should do a bit of reading to get up to speed.
Within WP-API, we’ve adopted the controller concept to have a standard pattern for the classes representing our resource endpoints. All resource endpoints extend
WP_REST_Controller to ensure they implement common methods.
HEAD, GET, POST, PUT, and DELETE Requests
These “HTTP verbs” represent the type of action a HTTP client might perform against a resource. For instance,
GET requests are used to fetch a Post’s data, whereas
DELETE requests are used to delete a Post. They’re collectively called “HTTP verbs” because they’re standardized across the web.
If you’re familiar with WordPress functions, a
GET request is the equivalent of
wp_remote_get(), and a
POST request is the same as
The phrase “HTTP Client” refers to the tool you use to interact with WP-API. You might use Postman (Chrome) or REST Easy (Firefox) to test requests in your browser, or httpie to test requests at the commandline.
WordPress itself provides a HTTP Client in the
WP_HTTP class and related functions (e.g.
wp_remote_get()). This can be used to access one WordPress site from another.
A “Resource” is a discrete entity within WordPress. You may know these resources already as Posts, Pages, Comments, Users, Terms, and so on. WP-API permits HTTP clients to perform CRUD operations against resources (CRUD stands for Create, Read, Update, and Delete).
Pragmatically, here’s how you’d typically interact with WP-API resources:
GET /wp-json/wp/v2/poststo get a collection of Posts. This is roughly equivalent to using
GET /wp-json/wp/v2/posts/123to get a single Post with ID 123. This is roughly equivalent to using
POST /wp-json/wp/v2/poststo create a new Post. This is roughly equivalent to using
DELETE /wp-json/wp/v2/posts/123to delete Post with ID 123. This is roughly equivalent to
Routes / Endpoints
Endpoints are functions available through the API. This can be things like retrieving the API index, updating a post, or deleting a comment. Endpoints perform a specific function, taking some number of parameters and return data to the client.
A route is the “name” you use to access endpoints, used in the URL. A route can have multiple endpoints associated with it, and which is used depends on the HTTP verb.
For example, with the URL `http://example.com/wp-json/wp/v2/posts/123`:
- The “route” is
wp/v2/posts/123– The route doesn’t include
wp-jsonis the base path for the API itself.
- This route has 3 endpoints:
get_itemmethod, returning the post data to the client.
update_itemmethod, taking the data to update, and returning the updated post data.
delete_itemmethod, returning the now-deleted post data to the client.
Note: On sites without pretty permalinks, the route is instead added to the URL as the
rest_route parameter. For the above example, the full URL would then be `http://example.com/?rest_route=wp/v2/posts/123`
A “schema” is a representation of the format for WP-API’s response data. For instance, the Post schema communicates that a request to get a Post will return
author, and other fields. Our schemas also indicate the type each field is, provide a human-readable description, and show which contexts the field will be returned in.