Create post wordpress.com using rest API

Standard way to create posts is to use cookies and nonce.

However I found a more easy way to do it.

1. Install Basic-Auth plugin to your wordpress.

2. Create wordpress user with username admin and password admin (both credentials are insecure, used for demonstration purposes only)

3. Create post using code:

   $username = 'admin';
   $password = 'admin';
   $rest_api_url = "http://my-wordpress-site.com/wp-json/wp/v2/posts";
   
   $data_string = json_encode([
       'title'    => 'My title',
       'content'  => 'My content',
       'status'   => 'publish',
   ]);
   
   $ch = curl_init();
   curl_setopt($ch, CURLOPT_URL, $rest_api_url);
   curl_setopt($ch, CURLOPT_POST, 1);
   curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
   
   curl_setopt($ch, CURLOPT_HTTPHEADER, [
       'Content-Type: application/json',
       'Content-Length: ' . strlen($data_string),
       'Authorization: Basic ' . base64_encode($username . ':' . $password),
   ]);
   curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
   
   $result = curl_exec($ch);
   
   curl_close($ch);
   
   if ($result) {
       // ...
   } else {
       // ...
   }
   

Note that in example above version 2 of REST API is used.

The answer is right that we can use the "Basic-Auth" plugin to make a Rest API request.

But, @vallez want to create a post on wordpress.com website.

And wordpress.com provide the oAuth support for authentication.

Recently I have created a post which demostrate about using the oAuth to create a post on wordpress.com. You can read the article at create the post on wordpress.com site using oAuth and Rest API

Below are the steps to successfully create a post with oAuth on wordpress.com.

Step 1: Add authentication details to get auth key.

$auth_args = array(
    'username'      => '',
    'password'      => '',
    'client_id'     => '',
    'client_secret' => '',
    'grant_type'    => 'password', // Keep this as it is.
);
$access_key = get_access_key( $auth_args );

Below is the function get_access_key() which return the access key.

Step 2: Get Access Key.

/**
 * Get Access Key.
 * 
 * @param  array $args  Auth arguments.
 * @return mixed        Auth response.
 */
function get_access_key( $args ) {

    // Access Token.
    $curl = curl_init( 'https://public-api.wordpress.com/oauth2/token' );
    curl_setopt( $curl, CURLOPT_POST, true );
    curl_setopt( $curl, CURLOPT_POSTFIELDS, $args );
    curl_setopt( $curl, CURLOPT_RETURNTRANSFER, 1);
    $auth = curl_exec( $curl );
    $auth = json_decode($auth);

    // Access Key.
    return $auth->access_token;
}

Step 3: Set post arguments and pass it create the post.

$post_args = array(
    'title'       => 'Test Post with oAuth',
    'content'     => 'Test post content goes here..',
    'tags'        => 'tests',
    'post_status' => 'draft',
    'categories'  => 'API',
);

Step 4: Create a post with the access key.

Now, We have access key and the create post arguments. So, Lets pass them to function create_post().

create_post( $access_key, $post_args );

Step 5: Create a post with access key.

/**
 * Create post with access key.
 * 
 * @param  string $access_key   Access key.
 * @param  array $post_args     Post arguments.
 * @return mixed                Post response.
 */
function create_post( $access_key, $post_args )
{
    $options  = array (
        'http' => array(
            'ignore_errors' => true,
            'method'        => 'POST',
            'header'        => array(
                0 => 'authorization: Bearer ' . $access_key,
                1 => 'Content-Type: application/x-www-form-urlencoded',
            ),
            'content' => http_build_query( $post_args ),
        ),
    );
     
    $context  = stream_context_create( $options );
    $response = file_get_contents(
        'https://public-api.wordpress.com/rest/v1/sites/YOURSITEID/posts/new/',
        false,
        $context
    );
    return json_decode( $response );
}

Incase, someone is getting 401 Unauthorized error when using REST API with application password, make sure that you use WordPress username (not Application Password Name) and Application Password

{"code":"rest_cannot_manage_templates","message":"Sorry, you are not allowed to access the templates on this site.","data":{"status":401}}