# TwitchEventSub
Twitch EventSub for Elixir.
## Installation
The package can be installed by adding `twitch_eventsub` to your list of
dependencies in `mix.exs`:
```elixir
def deps do
[
{:hello_twitch_eventsub, "~> 0.1.5"}
]
end
```
If you are using the websocket eventsub, add:
{:websockex, "~> 0.4"},
If you are using webhooks with Plug (and you are not already using Phoenix or Plug, add:
{:plug, "~> 1.15"},
### Setup
* You need to create an app on the [Twitch Developer Console](https://dev.twitch.tv/console/apps/create)
to get the `client_id` and `client_secret`.
You can get an OAuth token from the command line, or using `twitchapps.com`.
#### CLI version (recommended)
* Add a `redirect_uri` to your app on the developer console that looks like:
`http://localhost:42069/oauth/callback`
* [Optional] set `TWITCH_CLIENT_ID`, `TWITCH_CLIENT_SECRET`, and `TWITCH_AUTH_SCOPE`
environment variables. For the auth scope you can use the example in the code
block further down this page.
* Run `mix help auth.token` to see the available options.
* You can specify the auth-specific options or exclude them and the app will use the
optional environment variables noted above.
* If you output `--json` then it will be easy to revoke and refresh your token during
development.
**IMPORTANT NOTE:** add `.twitch.json` to your `.gitignore` file.
#### Twitchapps.com version
* Add the redirect URL to your app: `https://twitchapps.com/tokengen/`.
* Go to the [Twitch OAuth Token Generator](https://twitchapps.com/tokengen/) and
paste in your `client_id` and the scopes you want (see the example below you can use).
##### Example Scopes
For scopes, I just use all the `read` scopes except for `whisper` and `stream_key`.
If you want to do the same, just paste the below into the `scopes` field on the
token generator page:
```
analytics:read:extensions analytics:read:games bits:read channel:read:ads channel:read:charity channel:read:goals channel:read:guest_star channel:read:hype_train channel:read:polls channel:read:predictions channel:read:redemptions channel:read:subscriptions channel:read:vips moderation:read moderator:read:automod_settings moderator:read:blocked_terms moderator:read:chat_settings moderator:read:chatters moderator:read:followers moderator:read:guest_star moderator:read:shield_mode moderator:read:shoutouts user:read:blocked_users user:read:broadcast user:read:email user:read:follows user:read:subscriptions channel:bot chat:read user:bot user:read:chat
```
If you want to do moderation things with this token, then you can add the required scopes for
your actions found here [https://dev.twitch.tv/docs/authentication/scopes](https://dev.twitch.tv/docs/authentication/scopes/).
#### Config files example (if using `.twitch.json` for local dev)
```elixir
# config/runtime.exs
twitch_access_token =
case config_env() do
:prod ->
System.fetch_env!("TWITCH_ACCESS_TOKEN")
_dev_or_test ->
File.read!(".twitch.json")
|> Jason.decode!()
|> Map.fetch!("access_token")
end
config :my_app,
event_sub: [
user_id: "123456",
channel_ids: ["123456"],
handler: MyApp.TwitchEvents,
client_id: System.fetch_env!("TWITCH_CLIENT_ID"),
access_token: twitch_access_token,
# Webhook secret is only if you are using webhooks.
webhook_secret: System.fetch_env!("TWITCH_WEBHOOK_SECRET")
]
```
#### Config options (EventSub)
* `:user_id` - The twitch user ID of the user that your token is for.
* `:channel_ids` - The twitch user ID of the broadcaster channels that you are subscribing to.
* `:handler` - A module that `use`s `TwitchEventSub` and implements the `TwitchEventSub.Handler` behaviour.
* `:client_id` - The client ID of the application you used for the token.
* `:access_token` - The OAuth token you generated with the correct scopes for your subscriptions.
* `:subscriptions` - Optional. The list of subscriptions to create. See below for more info.
Defaults to:
```elixir
# Default subscriptions.
~w[
channel.chat.message channel.chat.notification
channel.ad_break.begin channel.cheer channel.follow channel.subscription.end
channel.channel_points_custom_reward_redemption.add
channel.channel_points_custom_reward_redemption.update
channel.charity_campaign.donate channel.charity_campaign.progress
channel.goal.begin channel.goal.progress channel.goal.end
channel.hype_train.begin channel.hype_train.progress channel.hype_train.end
channel.shoutout.create channel.shoutout.receive
stream.online stream.offline
]
```
All of the above subscriptions will work without passing conditions, as long as you
provide the `broadcaster_user_id` and `user_id` fields to the config.
Other subscriptions require different conditions, so if you add them, you need to add the subscription
as a map, and include the condition. Example:
```elixir
config :my_app,
event_sub: [
subscriptions: [
"channel.chat.message",
"channel.chat.notification",
"channel.ad_break.begin",
"channel.cheer",
# etc...
# Add a map of attrs for subscriptions.
# Required fields are `:name`, and `:condition`.
# See the Twitch docs for the required and optional conditions.
%{
name: "channel.channel_points_custom_reward_redemption.add",
condition: %{
broadcaster_user_id: "1337",
reward_id: "92af127c-7326-4483-a52b-b0da0be61c01"
}
}
]
]
```
#### Config options (Websocket-specific)
* `:url` - Optional. The URL for the Twitch EventSub websocket server. Defaults to Twitch.
* `:keepalive_timeout` - Optional. The keepalive timeout in seconds. Specifying an invalid,
but numeric value will return the nearest acceptable value. Defaults to `10`.
* `:start?` - Optional. A boolean value of whether or not to start the eventsub socket.
Defaults to `false` if there are no `event_sub` config options.
#### Config options (Webhook-specific)
* `:webhook_secret` - The secret to be used when creating and receiving subscriptions.
### Handler module
Create a bot module to deal with chat messages or events:
```elixir
defmodule MyApp.TwitchEvents do
use TwitchEventSub
@impl true
def handle_event("channel.follow", event) do
# TODO: Do something when you get a follow?
end
end
```
### Starting Websocket
Examples of adding Twitch EventSub websocket to your application's supervision tree below.
```elixir
# lib/my_app/application.ex in `start/2` function:
defmodule MyApp.Application do
# ...
def start(_type, _args) do
children = [
# ... existing stuff ...
# Add the bot.
{TwitchEventSub.WebSocket, Application.fetch_env!(:my_app, :event_sub)}
]
# ...
end
# ...
end
```
