Write bots for Discord in Haskell.

Functions and data types to write discord bots. Official discord docs https://discord.com/developers/docs/reference.

See the project readme for quickstart notes https://github.com/discord-haskell/discord-haskell#discord-haskell-

discord-haskell

Build that discord bot in Haskell! Also checkout the calamity haskell library for a more advanced interface.

Documentation

[installing] [debugging] [creating-bot]

[app-commands] [components] [cache] [embeds] [emoji] [intents] [voice]

[design] [contributing] [todo]

Example

This is an example bot that replies "pong" to messages that start with "ping". Checkout the other examples for things like state management.

{-# LANGUAGE OverloadedStrings #-}  -- allows "string literals" to be Text
import           Control.Monad (when, void)
import           UnliftIO.Concurrent
import           Data.Text (isPrefixOf, toLower, Text)
import qualified Data.Text.IO as TIO

import           Discord
import           Discord.Types
import qualified Discord.Requests as R

-- | Replies "pong" to every message that starts with "ping"
pingpongExample :: IO ()
pingpongExample = do
    userFacingError <- runDiscord $ def
             { discordToken = "Bot ZZZZZZZZZZZZZZZZZZZ"
             , discordOnEvent = eventHandler
             , discordOnLog = \s -> TIO.putStrLn s >> TIO.putStrLn ""
             } -- if you see OnLog error, post in the discord / open an issue

    TIO.putStrLn userFacingError
    -- userFacingError is an unrecoverable error
    -- put normal 'cleanup' code in discordOnEnd (see examples)

eventHandler :: Event -> DiscordHandler ()
eventHandler event = case event of
    MessageCreate m -> when (isPing m && not (fromBot m)) $ do
        void $ restCall (R.CreateReaction (messageChannelId m, messageId m) "eyes")
        threadDelay (2 * 10^6)
        void $ restCall (R.CreateMessage (messageChannelId m) "Pong!")
    _ -> return ()

fromBot :: Message -> Bool
fromBot = userIsBot . messageAuthor

isPing :: Message -> Bool
isPing = ("ping" `isPrefixOf`) . toLower . messageContent

Discord Server

Ask questions, get updates, request features, etc in the project discord server: https://discord.gg/eaRAGgX3bK

Official Discord Documentation

This api closley matches the official discord documentation, which lists the rest requests, gateway events, and gateway sendables.

You can use the docs to check the name of something you want to do. For example: the docs list a Get Channel API path, which translates to discord-haskell's rest request ADT for GetChannel of type ChannelId -> ChannelRequest Channel.

Open an Issue

If something goes wrong: check the error message (optional: check the debugging logs), make sure you have the most recent version, ask on discord, or open a github issue.