In pure clientside
- Followers - https://dev.twitch.tv/docs/api/reference#get-users-follows - Long Poll for updates
- Bits - https://dev.twitch.tv/docs/pubsub - Twitch will send data to the socket when data occurs.
- Subscribers - pubsub as well
- Chat - https://dev.twitch.tv/docs/irc - Chat over websockets.
For pure client side you’d normally use implicit auth https://dev.twitch.tv/docs/authentication/getting-tokens-oauth#oauth-implicit-code-flow