Hello World Bot

This section revolves around simple Serenity examples you can get quickly started with by following these 4 steps:

1. Go through the steps in Prerequisites below
2. Initialize a new Serenity project by running the cargo shuttle init --template serenity command
3. Copy pasting the contents of the example you want to deploy — make sure to check the tabs of the snippet(s) to ensure you are copying the right code/file
4. Running the cargo shuttle deploy command

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Prerequisites

To get started log in to the Discord developer portal.

1. Click the New Application button, name your application and click Create.
2. Navigate to the Bot tab in the lefthand menu, and add a new bot.
3. On the bot page click the Reset Token button to reveal your token. Put this token in your Secrets.toml. It’s very important that you don’t reveal your token to anyone, as it can be abused. Create a .gitignore file to omit your Secrets.toml from version control.
4. For the sake of this example, you also need to scroll down on the bot page to the Message Content Intent section and enable that option.

To add the bot to a server we need to create an invite link.

1. On your bot’s application page, open the OAuth2 page via the lefthand panel.
2. Go to the URL Generator via the lefthand panel, and select the bot scope as well as the Send Messages permission in the Bot Permissions section.
3. Copy the URL, open it in your browser and select a Discord server you wish to invite the bot to.

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Code

This example shows how to build a Serenity bot with Shuttle that responds to the !hello command with world!.

use anyhow::anyhow;
use serenity::async_trait;
use serenity::model::channel::Message;
use serenity::model::gateway::Ready;
use serenity::prelude::*;
use shuttle_secrets::SecretStore;
use tracing::{error, info};

struct Bot;

#[async_trait]
impl EventHandler for Bot {
    async fn message(&self, ctx: Context, msg: Message) {
        if msg.content == "!hello" {
            if let Err(e) = msg.channel_id.say(&ctx.http, "world!").await {
                error!("Error sending message: {:?}", e);
            }
        }
    }

    async fn ready(&self, _: Context, ready: Ready) {
        info!("{} is connected!", ready.user.name);
    }
}

#[shuttle_runtime::main]
async fn serenity(
    #[shuttle_secrets::Secrets] secret_store: SecretStore,
) -> shuttle_serenity::ShuttleSerenity {
    // Get the discord token set in `Secrets.toml`
    let token = if let Some(token) = secret_store.get("DISCORD_TOKEN") {
        token
    } else {
        return Err(anyhow!("'DISCORD_TOKEN' was not found").into());
    };

    // Set gateway intents, which decides what events the bot will be notified about
    let intents = GatewayIntents::GUILD_MESSAGES | GatewayIntents::MESSAGE_CONTENT;

    let client = Client::builder(&token, intents)
        .event_handler(Bot)
        .await
        .expect("Err creating client");

    Ok(client.into())
}