Redis

The Redis database is used as a cache and to store state of both the bot and chatters.

Here's a list of keys that keep track of stream and bot state:

NAME	FUNCTION	STATE
anivmessages	Store last aniv and aneev messages in JSON format	Always exists
rouletteCount	How many bullets have been fired with the roulette command	Always exists
timeoutStacking	Stores if timeout stacking is on	Exists if true, doesn't if false
streamIsLive	Stores if the stream is live	Exists if true, doesn't if false
disabledcommands	Stores a set of disabled commands and items	Each string in the set represents a command/item
disabledcheers	Stores a set of disabled cheers	Each string in the set represents a cheer

To act as a cache, redis stores the userid, displayname and username.

The expiration is 30 minutes.

When creating a user object, the id gets stored in userlookup:{username}, the displayname in user:{userid}:displayName and the username in user:{userid}:username.

When looking up an id, you can see if they exist in userlookup, and when getting the displayname, you can use user:123:displayName. This is all done by the User class.

Besides caching user data, redis has a lot more important information about users:

These are all stored in user:{id}:

NAME	FUNCTION	STATE
admin	Is the user an admin	Exists if true, doesn't if false
bot	Is the user a bot	Exists if true, doesn't if false
haschatted	Has the user chatted in chat before	Exists if true, doesn't if false
invulnerable	Is the user invulnerable	Exists if true, doesn't if false
mod	Is the user a moderator in the channel	Exists if true, doesn't if false
welcomemessageid	Id of welcome message. So this message can be deleted after a ban	Exists for the first 10 minutes
subbed	Status of the subscription of the user	Exists if true, doesn't if false. Contains 1 for tier 1, 2 for tier 2 and 3 for tier 3
timeout	Is the user timed out or banned	Exists if true, doesn't if false. Has an expiration set for when the user is freed, or none if it's a permanent-ban
remod	Does this user get mod after timeout is over	Exists if true, doesn't if false
greedy	Is the user greedy with lootboxes	Exists if true, doesn't if false
vulnerable	Is the user vulnerable to random timeouts (grenade, tnt, silverbullet)	Exists if true, doesn't if false
itemlock	Prevents the user from using and giving items and qbucks	Exists if true, doesn't if false
haschattedthisstream	The user has chatted in the current livestream. All will be cleared after you go live	Exists if true, doesn't if false
welcomemessagetext	The message the user has set as their welcome message. No expiration	If this exists, will send this message on the first message for a stream

Note that all of these flags can or do have an expiration. Like the timeout flag, deletes itself when the user is freed

The haschatted flag only exists because twitch Eventsub subscription channel.chat.message doesn't tell you if the message is from a brand new chatter, unlike the soon-to-be-deprecated IRC API. There is an open request here