Hello,
is there an NC API doku?
Similar to https://doc.owncloud.org/api/ ?
when developing an app this is my main source of reference at the moment.
A bump to the NC server team…
There is none AFAIK. File an issue on the documentation repo if you think it’s important and maybe get your hands dirty 
For the REST-APIs I think it would be good to have a tool like Swagger in place which:
- allows to generate the API docs from code via annotations (I guess it works with PHP as well, never used it with that, but quick search gave me http://zircote.com/swagger-php/)
- lets you try the call right from the docs page via simple form
That would improve the docs on https://docs.nextcloud.com/server/12/developer_manual/client_apis/WebDAV/index.html as well as https://docs.nextcloud.com/server/12/developer_manual/client_apis/OCS/index.html, which by the way only shows one endpoint.
Since I’m new to Nextcloud development, I am not sure if the OCS API docs are actually complete (with only that one endpoint). For example, I don’t see how I would be able to retrieve document meta information, such as tags, via REST API, or if it’s actually possible at all.
bump, also 
It would be great to have at least a little more information about existing REST endpoints.
So we have these:
https://docs.nextcloud.com/server/16/developer_manual/client_apis/index.html
https://docs.nextcloud.com/server/16/developer_manual/core/ocs-share-api.html
https://docs.nextcloud.com/server/16/developer_manual/core/ocs-sharee-api.html
I’ve just done a PR to consolidate them under this one URL:
https://docs.nextcloud.com/server/16/developer_manual/client_apis/index.html
I’m sure they are not 100% complete, but should cover most use cases.