It appears HTMX supports non-HTML APIs. The json-enc extension encodes <form> fields as JSON, and client-side-templates allows templating from JSON (and others)

It appears HTMX supports non-HTML APIs. The json-enc extension encodes <form> fields as JSON, and client-side-templates allows templating from JSON (and others) API responses. Now, take my words with a grain of salt because i'm unaware of the details, but i don't see a reason HTMX couldn't support XML with proper schemas which would be great: - for structured/typed data and ensuring proper API protocol negotiation between client and server - for data structures closer to the DOM model (which has both fields and children for most elements, while a JSON key can point to a list or an object, not both) - for serialization formats the browser knows about and is optimized for - for interoperability with other systems/protocols based on XML schemas, such as XMPP Data can be served in many forms. Your API could be a DNS key-value server, or a JSON endpoint, or a HTML page. Just because most people don't structure their HTML semantically doesn't mean it can't (or shouldn't) be done, which means you don't loose "access to data as data". On the contrary, designing your API as semantic/structured HTML empowers users to parse/script your website to better suit their needs, whether that's for accessibility purposes or for developing 3rd party clients. Something that's become almost impossible in the age of SPAs and CAPTCHAs imposing the developer's will on my browsing experience.