fishdan Jsonmaker lets administrators curate a nested tree of links directly on the front end. Drop the <code>[jsonmaker]</code> shortcode onto a page, expand nodes to add children, rename or remove items inline, and fetch any branch at <code>/json/<slug>.json</code>.
Highlights
<ul>
<li>Inline “Add”, “Edit”, and “Delete” controls for administrators (capability <code>jsonmaker_manage</code>).</li>
<li>Clean JSON endpoint for each node (<code>/json/<slug>.json</code>).</li>
<li>Store either URLs or plain text values; an empty value keeps a node as a container.</li>
<li>All data persists in a single WordPress option—no custom tables.</li>
</ul>

fishdan Jsonmaker

Manage hierarchical link collections via a shortcode, edit them inline, and expose any node as JSON.

Pete Nelson

WordPress plugin to log <a href="http://v2.wp-api.org/" rel="nofollow ugc">REST API</a> requests and responses (for v2 of the API).
Includes:
<ul>
<li>WordPress admin page to view and search log entries</li>
<li>API endpoint to access log entries via JSON</li>
<li>Filters to customize logging</li>
<li>Custom endpoint logging</li>
<li>ElasticPress logging</li>
</ul>
Find us on <a href="https://github.com/petenelson/wp-rest-api-log" rel="nofollow ugc">GitHub</a>!
Roadmap
<ul>
<li>Better search capabilities for log entries via the REST API endpoint</li>
</ul>

REST API Log

Exactly what I needed

its trash.
whilst i do like the idea of the plugin, this tool is simply not working properly. guess it's abandoned. 
there is a filter build in to filter for the request type, but it does not work (simply doesn't filter at all). and there is an option, to purge logs, that are older than x days, but this doesn't work ether. and deleting the logs takes ages, you might want to do that in the db directly. so handle with care, as it will bloat the db and it'll be hard to find the data, you might be looking for..

don't!!1!

This is great tool to log REST API calls. Period.

1 star? 5 stars!

WordPress plugin to log REST API requests and responses

fishdan Jsonmaker vs REST API Log