Adding Varnish should be straightforward but AFAIK there is no existing docs about this yet.

Alternatively, you could use Souin or the Caddy cache-handle, which should switch to Souin soon.

Thanks for the info.

A Cache-Plugin for Caddy will be great with APIP-Support. There is a lot of good ideas on the Todo-List. I am looking forward to it. But it looks that it is not production ready yet. Is there any documentation to use it with APIP 2.6?
Cache-Handler
Souin

I made a proof of concept, but there is still a lot of work.
#1961

Hi @Chris53897 the cache-handler and Souin are available as Caddy module you just have to add either --with github.com/caddy/cache-handler or --with github.com/darkweak/souin/plugins/caddy in the api/Dockerfile and base your Caddyfile declaration (located inside the api/docker/caddy/Caddyfile) according to the selected repository.
Souin Caddy sample configurations
cache-handler

Souin is in a better state at present for handling Cache than cache-handler (which will eventually be equivalent to the Souin caddy plugin AFAIK).

Presently Souin has some quirks to resolve with building the Caddy plugin module via xcaddy. It does seem promising and I plan to try it out soon myself (unrelated to api-platform).

I am still in an evaluation stage myself, but from what I've read of Varnish through their docs, they seem to have a rather decent solution, while Souin as a Caddy module (when ready) looks to be competitive and offer a better UX.

Souin docs and examples need improvement at present, and I may contribute to that if I adopt it for production use, in the meantime I would advise Varnish if you have advanced requirements (more established ecosystem, community/resources, detailed docs, examples, resulting in less friction).