svrooij

Since wordpress version 4.9.? wordpress includes the functionality provided by this plugin in the core of wordpress.
Checkout https://developer.wordpress.org/rest-api/using-the-rest-api/global-parameters/#_fields for functionality included in the wordpress core, 
they made it even better by filtering the amount of data pulled from the database.
This plugin will no longer be maintained since it has been superseded by the core functionality.
The <a href="https://wordpress.org/plugins/rest-api/" rel="ugc">wp-rest-api-v2</a> returns a lot of properties. 
It could be very useful (or mobile-data-friendly) to only return the properties needed by the application.
If you only want titles and links of some articles it doesn’t make sense to return the content or the excerpt.
This isn’t limited to posts, it also works on custom posttypes, categories, pages, terms, taxonomies and comments.
Instead of returning:
<pre><code>{
 "id": 2138,
 "date": "2015-10-25T15:31:03",
 "guid": {
 "rendered": "http://worldofict.nl/?p=2138"
 },
 "modified": "2015-10-25T15:31:03",
 "modified_gmt": "2015-10-25T14:31:03",
 "slug": "rechtenvrije-fotos",
 "type": "post",
 "link": "http://worldofict.nl/tip/2138-rechtenvrije-fotos/",
 "title": {
 "rendered": "Rechtenvrije foto’s"
 },
 "content": {
 "rendered": ".. A lot of content .. "
 },
 "excerpt": {
 "rendered": " .. A lot of content ..."
 },
 "author": 2,
 "featured_image": 2139,
 "comment_status": "open",
 "ping_status": "open",
 "sticky": false,
 "format": "standard",
 //.. even more tags ....
}
</code></pre>
It can return (with <code>fields=id,title.rendered,link</code> as GET parameter)
<pre><code>{
 "id": 2138,
 "link": "http://worldofict.nl/tip/2138-rechtenvrije-fotos/",
 "title": {
 "rendered": "Rechtenvrije foto’s"
 }
}
</code></pre>
<h4>Notes</h4>
<ol>
<li>If you specify fields so it wouldn’t return data the default response is send back to the client.</li>
<li>(for developers) something wrong with this plugin? <a href="https://github.com/svrooij/rest-api-filter-fields/" rel="nofollow ugc">Github</a></li>
<li>If you liked the plugin <a href="https://github.com/sponsors/svrooij" rel="nofollow ugc">consider sponsoring me</a></li>
</ol>

REST API – Filter Fields

This is hands-down the best REST API extension available.

Best REST API plugin

Filter the properties returned by the Wordpress rest api V2 (only needed until wordpress 4.9)

REST API Featured Image is a lightweight yet powerful plugin that simplifies how to retrieve featured images via the WordPress REST API. By introducing a top-level field called <code>featured_media_src_url</code>, this plugin embeds the direct URL of the featured image into your REST API responses. This eliminates the need for additional API calls to fetch featured images, resulting in faster load times and enhanced site performance.
Key Features:
– Direct Access to Featured Image URL: Adds <code>featured_media_src_url</code> to REST API responses, providing immediate access to the featured image URL. 
– Performance Optimization: Reduces the number of API requests, improving the speed and efficiency of your applications. 
– Custom Post Type Support: Fully supports custom post types, allowing you to enable or disable the featured image URL field for specific post types through the admin settings. 
– User-Friendly Configuration: Easy to install and configure without any coding.
Why Use REST API Featured Image?
When developing applications or themes that rely on the WordPress REST API, accessing the featured image typically requires an additional request for each post. This can be time-consuming and may negatively impact site performance. REST API Featured Image addresses this issue by including the featured image URL directly in the REST API response, saving you time and resources.
REST API Featured Image Field:
– <code>featured_media_src_url</code>

REST API Featured Image

Enhance your WordPress REST API by adding a featured image URL field directly to API responses, improving performance by eliminating extra requests.

REST API – Filter Fields vs REST API Featured Image