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.

Daniel Bachhuber

Ryan McCue

Jonny Harris

Joe Hoyle

Rachel Baker

This plugin uses the OAuth 1.0a protocol to allow delegated authorization; that is, to allow applications to access a site using a set of secondary credentials. This allows server administrators to control which applications can access the site, as well as allowing users to control which applications have access to their data.
This plugin only supports WordPress >= 4.4.
The latest stable version is also available from the <a href="https://wordpress.org/plugins/rest-api-oauth1/" rel="ugc">WordPress Plugin Directory</a>.
<h3>New to OAuth</h3>
We strongly recommend you use an existing OAuth library. You’ll be best off if you understand the authorization process, but leave the actual implementation to well-tested libraries, as there are a lot of edge cases.
Start reading from <a href="docs/introduction/README.md" rel="nofollow ugc">the Introduction</a> to get started!
<h3>For OAuth Veterans</h3>
If you already know how to use OAuth, here’s the lowdown:
<ul>
<li>The plugin uses OAuth 1.0a in</li>
<li>We use the three-legged flow</li>
<li>To find the REST API index, apply the <a href="http://v2.wp-api.org/guide/discovery/" rel="nofollow ugc">API autodiscovery process</a></li>
<li>The endpoints for the OAuth process are available in the REST API index: check for <code>$.authentication.oauth1</code> in the index data.
<ul>
<li>The temporary credentials (request token) endpoint is <code>$.authentication.oauth1.request</code> (typically <code>/oauth1/request</code>)</li>
<li>The authorization endpoint is <code>$.authentication.oauth1.authorize</code> (typically <code>/oauth1/authorize</code>)</li>
<li>The token exchange (access token) endpoint is <code>$.authentication.oauth1.access</code> (typically <code>/oauth1/access</code>)</li>
</ul>
</li>
<li>Your callback URL must match the registered callback URL for the application in the scheme, authority (user/password) host, port, and path sections. (Subpaths are not allowed.)</li>
<li>The only signature method supported is HMAC-SHA1.</li>
<li>OAuth parameters are supported in the Authorization header, query (GET) parameters, or request body (POST) parameters (if encoded as <code>application/x-www-form-urlencoded</code>). OAuth parameters are not supported in JSON data.</li>
</ul>

WP REST API – OAuth 1.0a Server

Hello, I have made an adapter for Parse Server under Node.js with which you can link the login of any installation of wordpress in Parse Server, for that I have used your plugin, which is the one that gives us access_token and allows us to verify the authenticity Of the user registered in the server.

https://github.com/enriquecerda/parse-server-wordpress-login

Links with Parse-server Node.js

Got this working after some good amount of work! Thanks for bringing this and making API calls secure.

Worked like a charm!

Really Useful And Good Plugin
But Please
1- Reply on The Support Forum
2- Update it To Work Good With Last WordPress Verison
3 – No Clear Docs
4 - not work with localhost

Good But

Connect applications to your WordPress site without ever giving away your password.

WP REST API Idempotent Requests vs WP REST API – OAuth 1.0a Server