• What are oAuth Tokens for?

They are mostly used to connect your chat bot or script to Twitch. Simply said you give them permissions to do whatever they’re supposed to.

That can be sending messages, updating stream title, game, status or reading various infos out of your Twitch account.

 

• What happens if I lose my token?

Nothing, simply generate a new one.

 

• What permissions does this token has?

Channel Editor: Write channel metadata (game, status, etc).
Channel Read: Read nonpublic channel information, including email address and stream key.
Channel stream: Reset a channel’s stream key.
Channel subscriptions: Read all subscribers to your channel.
Chat Login: Log into chat and send messages.
For a full overview of the permissions which exist: https://dev.twitch.tv/docs/authentication#scopes

 

• Do you save the tokens somewhere?

No. You should also never share your token with anyone so they can’t get access to your account.