WordPress REST API for Beginners

What Is the REST API?

Traditionally, WordPress generates HTML pages when visitors request URLs. The REST API adds another layer: it provides WordPress data in a structured format (JSON) that other applications can understand. Instead of "give me the blog page," you can say "give me the post data for post ID 42."

This transforms WordPress from a website builder into a content platform. Your WordPress content can power mobile apps, custom front-ends, external dashboards, automated workflows, and integrations with other systems—all while you manage content in the familiar WordPress admin.

REST API Basics

What REST Means

REST (Representational State Transfer) is an architecture style for web services. Key concepts:

• Resources: Things you can access (posts, users, pages)
• Endpoints: URLs that represent resources
• Methods: Actions you can perform (GET, POST, PUT, DELETE)
• JSON: Data format for requests and responses

HTTP Methods

WordPress API Structure

The WordPress REST API follows a consistent URL pattern:

• yoursite.com/wp-json/ — API root
• yoursite.com/wp-json/wp/v2/ — WordPress core namespace
• yoursite.com/wp-json/wp/v2/posts — Posts endpoint
• yoursite.com/wp-json/wp/v2/posts/123 — Specific post

Default Endpoints

WordPress provides endpoints for all core content types.

Content Endpoints

• /wp/v2/posts — Blog posts
• /wp/v2/pages — Pages
• /wp/v2/media — Media library items
• /wp/v2/comments — Comments

Taxonomy Endpoints

• /wp/v2/categories — Categories
• /wp/v2/tags — Tags

User Endpoints

• /wp/v2/users — Users (public info only by default)
• /wp/v2/users/me — Current authenticated user

Settings and System

• /wp/v2/settings — Site settings (authenticated)
• /wp/v2/types — Registered post types
• /wp/v2/statuses — Post statuses

Making Requests

Using Your Browser

The simplest way to explore: just visit the URL. Open yoursite.com/wp-json/wp/v2/posts in your browser to see JSON data for your posts.

Using Command Line

# Get all posts
curl https://yoursite.com/wp-json/wp/v2/posts

# Get a specific post
curl https://yoursite.com/wp-json/wp/v2/posts/123

# Get posts with specific parameters
curl "https://yoursite.com/wp-json/wp/v2/posts?per_page=5&categories=10"

Common Parameters

• per_page — Number of results (max 100)
• page — Page number for pagination
• search — Search term
• categories — Filter by category ID
• tags — Filter by tag ID
• orderby — Sort field (date, title, etc.)
• order — Sort direction (asc, desc)

Understanding Responses

API responses include:

• Response body: The JSON data you requested
• Headers: Metadata including pagination info
• Status codes: Success (200), created (201), error (4xx, 5xx)

Authentication

Public content is accessible without authentication. Creating, editing, or deleting content requires authentication.

Authentication Methods

• Cookie authentication: For logged-in WordPress users (includes nonce)
• Application passwords: Built into WordPress 5.6+ for external apps
• OAuth: For third-party integrations (requires plugin)
• JWT tokens: Popular for headless setups (requires plugin)

Application Passwords

The simplest method for external applications:

1. Go to Users → Your Profile

   Scroll to Application Passwords section.

2. Create new application password

   Give it a descriptive name for the application using it.

3. Save the password

   Copy it immediately—it won't be shown again.

4. Use with Basic Auth

   Include username and application password in requests.

# Authenticated request with application password
curl --user "username:application_password" \
  https://yoursite.com/wp-json/wp/v2/posts

Creating and Updating Content

Creating a Post

curl --user "username:app_password" \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "title": "My New Post",
    "content": "This is the post content.",
    "status": "publish"
  }' \
  https://yoursite.com/wp-json/wp/v2/posts

Updating a Post

curl --user "username:app_password" \
  -X PUT \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Updated Title"
  }' \
  https://yoursite.com/wp-json/wp/v2/posts/123

Deleting a Post

# Move to trash
curl --user "username:app_password" \
  -X DELETE \
  https://yoursite.com/wp-json/wp/v2/posts/123

# Permanently delete
curl --user "username:app_password" \
  -X DELETE \
  https://yoursite.com/wp-json/wp/v2/posts/123?force=true

Practical Use Cases

Mobile Applications

Build iOS or Android apps that read and write WordPress content. Your team manages content in WordPress; users access it through native apps.

Headless WordPress

Use WordPress for content management, but display content through a custom front-end built with React, Vue, or other frameworks.

Integrations

• Sync content to external systems
• Trigger workflows when content changes
• Import content from other platforms
• Connect with marketing automation tools

Custom Dashboards

Build specialized interfaces that pull WordPress data but display it differently than the admin area—executive dashboards, editorial workflows, client portals.

Custom Endpoints

When built-in endpoints don't meet your needs, create custom ones.

Registering Custom Endpoints

add_action( 'rest_api_init', function() {
    register_rest_route( 'myplugin/v1', '/featured-content', array(
        'methods'  => 'GET',
        'callback' => 'get_featured_content',
        'permission_callback' => '__return_true',
    ));
});

function get_featured_content( $request ) {
    // Your logic to fetch featured content
    $data = array(
        'title' => 'Featured Item',
        'url'   => 'https://example.com',
    );
    return new WP_REST_Response( $data, 200 );
}

When to Create Custom Endpoints

• Combining data from multiple sources
• Complex queries not possible with default endpoints
• Exposing custom post type data
• Creating simplified responses for specific apps

Getting Started

The REST API opens WordPress to possibilities beyond traditional websites. You don't need to use it for everything—sometimes a standard WordPress site is exactly right. But understanding the API prepares you for projects that need more flexibility.

Start by exploring the API on your own site. Visit /wp-json/ and browse the endpoints. Try fetching posts with different parameters. Experiment with tools like Postman. The API is already there, waiting to be used.