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.

Themeisle

Hardeep Asrani

Blocks Export Import plugin allows you to import and export blocks as JSON in Gutenberg Block Editor.
All the code and sources for this plugin are publicly available as part of https://github.com/Codeinwp/otter-blocks.

Blocks Export Import – Backup & Move Gutenberg Blocks as JSON

Fantastic and easy

Export and import Gutenberg blocks as JSON files. Backup block layouts, move them between sites, or share them with your team — all without plugins.

fishdan Jsonmaker vs Blocks Export Import – Backup & Move Gutenberg Blocks as JSON