Thanks again. By relevant Twitch API endpoints - do you mean https://dev.twitch.tv/docs/api/reference#get-streams ?
I was thinking you could listen to the https://dev.twitch.tv/docs/api/webhooks-reference#topic-stream-changed webhook and then poll the above from when a stream started until it ended, but that won’t give you post-stream metrics, like views after the stream ended (replays).