Default API endpoints in Wordpress - Step-by-Step Execution

Concept Flow - Default API endpoints

WordPress Site

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REST API Initialized

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Default Endpoints Registered

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Client Sends HTTP Request

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Endpoint Matches Request

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Process Request & Return JSON Response

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Client Receives Data

WordPress sets up default REST API endpoints that listen for HTTP requests and return JSON data automatically.

Execution Sample

Wordpress

GET /wp-json/wp/v2/posts
GET /wp-json/wp/v2/pages
GET /wp-json/wp/v2/users

These are example HTTP GET requests to default WordPress REST API endpoints to fetch posts, pages, and users.

Execution Table

Step	Action	Request URL	Endpoint Matched	Response Type	Result
1	Client sends HTTP GET	/wp-json/wp/v2/posts	/wp/v2/posts	JSON	List of posts returned
2	Client sends HTTP GET	/wp-json/wp/v2/pages	/wp/v2/pages	JSON	List of pages returned
3	Client sends HTTP GET	/wp-json/wp/v2/users	/wp/v2/users	JSON	List of users returned
4	Client sends HTTP GET	/wp-json/wp/v2/comments	/wp/v2/comments	JSON	List of comments returned
5	Client sends HTTP GET	/wp-json/wp/v2/nonexistent	No match	404 Error	Endpoint not found
6	Client sends HTTP POST	/wp-json/wp/v2/posts	/wp/v2/posts	JSON	New post created (if authorized)
7	Client sends HTTP GET	/wp-json/	Root API	JSON	API index with available namespaces
8	Client sends HTTP GET	/wp-json/wp/v2/	/wp/v2 root	JSON	List of available routes in wp/v2 namespace

💡 Requests to unknown endpoints return 404; authorized POST requests create or update data.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 5	After Step 6
Request URL	None	/wp-json/wp/v2/posts	/wp-json/wp/v2/pages	/wp-json/wp/v2/users	/wp-json/wp/v2/nonexistent	/wp-json/wp/v2/posts
Endpoint Matched	None	/wp/v2/posts	/wp/v2/pages	/wp/v2/users	No match	/wp/v2/posts
Response	None	Posts JSON	Pages JSON	Users JSON	404 Error	Post Created JSON

Key Moments - 3 Insights

Why does a request to /wp-json/wp/v2/nonexistent return a 404 error?

Because there is no default endpoint registered for 'nonexistent', so the API returns a 404 as shown in execution_table step 5.

Can you create a new post by sending a GET request to /wp-json/wp/v2/posts?

No, GET requests only fetch data. Creating a post requires a POST request as shown in step 6.

What does the root API endpoint /wp-json/ return?

It returns a JSON index of available namespaces and routes, helping clients discover API endpoints, as in step 7.

Visual Quiz - 3 Questions

Look at the execution_table, what response does the client get when requesting /wp-json/wp/v2/users?

A A list of users in JSON format

B A 404 error

C A list of posts

D An HTML page

💡 Hint

Check execution_table row 3 under 'Response Type' and 'Result'

At which step does the API return a 404 error?

A Step 2

B Step 6

C Step 5

D Step 1

💡 Hint

Look for '404 Error' in the 'Response Type' column in execution_table

If the client sends a POST request to /wp-json/wp/v2/posts, what happens according to the execution_table?

A A list of posts is returned

B A new post is created if authorized

C A 404 error is returned

D Nothing happens

💡 Hint

See step 6 in execution_table under 'Action' and 'Result'

Concept Snapshot

WordPress default API endpoints are URLs like /wp-json/wp/v2/posts.
They respond to HTTP requests with JSON data.
GET requests fetch data; POST requests create or update data.
Unknown endpoints return 404 errors.
The root /wp-json/ shows available API namespaces.

Full Transcript

WordPress automatically sets up default REST API endpoints under the /wp-json/ URL. When a client sends an HTTP request like GET /wp-json/wp/v2/posts, WordPress matches this to the posts endpoint and returns a JSON list of posts. Similarly, requests to pages, users, and comments endpoints return their respective data. If the client requests an endpoint that does not exist, such as /wp-json/wp/v2/nonexistent, the API returns a 404 error. POST requests to endpoints like /wp-json/wp/v2/posts can create new content if the client is authorized. The root API endpoint /wp-json/ returns a JSON index of available namespaces and routes to help clients discover the API. This flow ensures WordPress sites provide a standard way to access and manipulate site data via HTTP requests.