How would I go dynamicaly adding Automation and Tags (and helpers)?

Hi ! I wanna set up a music player with home assistant, with scannable tag as well as button in the dashboard to start a specific playlist / album.
I was hopping to be able to write a script of some sort to list all of my playlist and automaticaly add them to HA.
However i cannot find a way to do it dynamicaly. I was hopping for some sort of Rest API
I imagine something like PUSH \api\automations with the yaml config as the body and it would push it. Similarly for tags PUSH \api\tags to add a new tag. However i cannot find something like that in the doc. Am i missing something.

Maybe it’s not even the right approch ?
Maybe i need to write a custom integration to simulate that behavior ?

Did you manage to find a way to automate the creation of tags?