Other backends

Sanity is one of many headless CMSs. They fall into three groups, and each could host Unyson+ through a thin adapter once the shared core exists.

Open source, self-hosted

You can run these yourself, ship a plugin for them, and your users own everything.

CMS	What it is	Fit for Unyson+
Payload	Node.js and TypeScript with a React admin	The strongest open-source target. Block fields and custom admin components suit a builder
Strapi	A well-known open-source CMS with a plugin marketplace	Good. Its dynamic zones work like page sections
Directus	An admin and API on top of any SQL database	Weak. It is built for data more than pages
KeystoneJS	A developer-focused CMS	Weak. Its audience is smaller

These work like Sanity: someone else runs the service.

CMS	What it is	Fit for Unyson+
Sanity	Structured content with a customisable React Studio	The first target, and popular with Astro
Storyblok	Nested components with its own visual editor	Possible through its app marketplace, but it already does part of the job
Prismic	Section-based pages using "Slices"	Possible
Contentful	Aimed at larger companies, with an app framework	Possible, for a smaller and more expensive market
Hygraph	GraphQL-first	Weak. It is less visual

Content is stored as files in the project's repository.

CMS	What it is	Fit for Unyson+
TinaCMS	Visual editing over Markdown and JSON files; pairs well with Astro	Good for a file-based editor
Decap CMS	A simple editor, formerly Netlify CMS	Weak. It is simple and dated

WordPress itself can be the backend, and it needs the least new work: editors keep the Unyson+ builder they know. See Headless WordPress.