Timothy Jacobs

When a network error is encountered, API clients should be able to retry a request without a risk of their request being processed twice. 
WP API Idempotence adds support for clients to include an idempotency key that uniquely identifies that request. If the server detects 
that a request with the same key has already been processed or is currently being processed, the response for the initial request will 
be returned.
For Example:
<pre><code>{
 "title": "My Important Post",
 "content": "This will only go out once!",
 "status": "draft",
 "idempotency_key": "1ced64e9-9537-4b7b-9919-444d9e15e201"
}
</code></pre>
<h4>Configuration</h4>
<ul>
<li>Idempotency key can either be passed in the request header or the request body.</li>
<li>The idempotency key name can be customized.</li>
<li>Change the HTTP methods the idempotency key is supported for. Defaults to <code>POST</code>, <code>PUT</code>, <code>PATCH</code>.</li>
</ul>
A sample request interface is included to demonstrate the selected configuration.
<h4>Developers</h4>
The plugin includes two actions to modify the dependency injection container (DIC) and insert custom services.
The <code>wp_api_idempotence_initialize_container_builder</code> action allows you to modify the Dependency Injection builder itself and 
the <code>wp_api_idempotence_initialize_container</code> action allows you to override dependencies. For example:
<pre><code>add_action( 'wp_api_idempotence_initialize_container', function( $container ) {
 $container->set( '_dataStore', DI\object( 'YourName\CustomDataStore' ) );
} );
</code></pre>
Under the hood, the plugin is made up of a <code>DataStore</code>, <code>RequestHasher</code>, <code>ResponseSerializer</code> and <code>RequestPoller</code>.
The <code>DataStore</code> is primarily responsible for retrieving or storing an idempotent request. By default, requests 
are stored in a custom database table. This could be substituted for a custom driver by implementing the <code>DataStore</code> 
interface. For example a Redis server.
The <code>RequestHasher</code> produces a unique hash for a <code>WP_REST_Request</code> object. This hash is based off of the contents of 
the request, not for the object via <code>spl_object_hash</code> or similar. This can also be substituted by implementing the 
 RequestHasher interface.
The <code>ResponseSerializer</code> converts a <code>WP_REST_Response</code> or <code>WP_Error</code> object back and forth from a string representation. 
The default JSON serializer supports filtering the serialization process using the <code>wp_api_idempotence_serialized_response_data</code> 
and <code>wp_api_idempotence_attach_serialized_response_data</code> filters. See <code>src/ResponseSerializer/Filtered.php</code>. 
The entire serializer can be substituted by implementing the <code>ResponseSerializer</code> interface.
Finally, the <code>RequestPoller</code> class polls the data store for a response if it is determined that an idempotent request 
is currently being processed when another request with the same key arrives. By default, the data store is polled 
every seconds a maximum of 15 times to try and retrieve a response object. If no response is found, an error with code 
 rest_duplicate_idempotency_key will be returned. This can be adjusted by overwriting the <code>poll.sleepSeconds</code> and 
 poll.maxQueries in the DIC. The <code>RequestPoller</code> can also be entirely subsituted by implementing the <code>RequestPoller</code> 
interface.
<h4>Contributing</h4>
This plugin is hosted on <a href="https://github.com/iron-bound-designs/wp-api-idempotence" rel="nofollow ugc">GitHub</a>. Issues and pull requests are welcomed.

WP REST API Idempotent Requests

Allow REST API clients to safely retry requests in case of network errors without risk of the request being processed twice.

Jason Bahl

Tyler

David Levine

Ryan Kanner

Geoff Taylor

Edwin Cromley

WPGraphQL is a free, open-source WordPress plugin that provides an extendable GraphQL schema and API for any WordPress site.
Get Started
<ol>
<li>Install WPGraphQL: <code>wp plugin install wp-graphql --activate</code></li>
<li>Try it out: <a href="https://repl.wpgraphql.com" rel="nofollow ugc">Live Demo</a></li>
<li>Read the <a href="https://wpgraphql.com/docs/quick-start" rel="nofollow ugc">Quick Start Guide</a>.</li>
<li>Join the <a href="https://discord.gg/AGVBqqyaUY" rel="nofollow ugc">Community on Discord</a> and <a href="https://github.com/wp-graphql/wp-graphql" rel="nofollow ugc">Star the Repo</a>!</li>
</ol>
Key Features
<ul>
<li>Flexible API: Query posts, pages, custom post types, taxonomies, users, and more.</li>
<li>Extendable Schema: Easily add functionality with WPGraphQL’s API, enabling custom integrations.</li>
<li>Compatible with Modern Frameworks: Works seamlessly with <a href="https://vercel.com/guides/wordpress-with-vercel" rel="nofollow ugc">Next.js</a>, <a href="https://docs.astro.build/en/guides/cms/wordpress/" rel="nofollow ugc">Astro</a>, <a href="https://www.okupter.com/blog/headless-wordpress-graphql-sveltekit" rel="nofollow ugc">SvelteKit</a>, and more.</li>
<li>Optimized Performance: Fetch exactly the data you need in a single query. Boost performance with <a href="https://github.com/wp-graphql/wp-graphql-smart-cache" rel="nofollow ugc">WPGraphQL Smart Cache</a>.</li>
</ul>
WPGraphQL is becoming a <a href="https://wordpress.org/news/2024/10/wpgraphql/" rel="ugc">Canonical Plugin</a> on WordPress.org, ensuring long-term support and a growing community of users and contributors.
<h4>Upgrading</h4>
It is recommended that anytime you want to update WPGraphQL that you get familiar with what’s changed in the release.
WPGraphQL publishes <a href="https://github.com/wp-graphql/wp-graphql/releases" rel="nofollow ugc">release notes on Github</a>.
WPGraphQL has been following Semver practices for a few years. We will continue to follow Semver and let version numbers communicate meaning. The summary of Semver versioning is as follows:
<ul>
<li>MAJOR version when you make incompatible API changes,</li>
<li>MINOR version when you add functionality in a backwards compatible manner, and</li>
<li>PATCH version when you make backwards compatible bug fixes.</li>
</ul>
You can read more about the details of Semver at semver.org
<h3>Privacy Policy</h3>
WPGraphQL uses <a href="https://appsero.com" rel="nofollow ugc">Appsero</a> SDK to collect some telemetry data upon user’s confirmation. This helps us to troubleshoot problems faster and make product improvements.
Appsero SDK does not gather any data by default. The SDK starts gathering basic telemetry data only when a user allows it via the admin notice.
Learn more about how <a href="https://appsero.com/privacy-policy/" rel="nofollow ugc">Appsero collects and uses this data</a>.
Learn more about how <a href="https://appsero.com/privacy-policy/" rel="nofollow ugc">Appsero collects and uses this data</a>.

WPGraphQL


I operate a large blog that uses WordPress as a headless CMS with a Next.JS frontend, which is largely enabled by this plugin. Let me just say first that creating an entire alternative third-party data API is an ambitious undertaking and I appreciate all the work the authors have put into it.



But as a developer I have to throw out a word of caution that this plugin often has major bugs that can have critical impact on your production website. For example after a recent minor update  we discovered a bug where any URL with a special character in it started returning a 404, causing several of our pages to suddenly become unavailable to users and delisted from Google, and this went on for many months before we realized it.



There have been many similar instances. My general approach is to lean more on WordPress's REST API over time which is more reliable since it's maintained by the WordPress team, and only use WPGraphQL when it's necessary.



Also recommend turning off auto-updates and test your website extremely thoroughly after any upgrade.


Unreliable

GraphQL vs. REST API
  10    :     0

Thank you for this plugin. Building my headless application with WPGraphQL is fun. 
The repl interface to test queries is A+.

Speedy

WPGraphQL adds a flexible and powerful GraphQL API to WordPress, enabling efficient querying and interaction with your site's data.

WP REST API Idempotent Requests vs WPGraphQL