serenity

Serenity is a Rust library for the Discord API.

View the examples on how to make and structure a bot.

Serenity supports bot login via the use of Client::builder.

You may also check your tokens prior to login via the use of validate_token.

Once logged in, you may add handlers to your client to dispatch Events, by implementing the handlers in a trait, such as EventHandler::message. This will cause your handler to be called when a Event::MessageCreate is received. Each handler is given a Context, giving information about the event. See the client's module-level documentation.

The Shard is transparently handled by the library, removing unnecessary complexity. Sharded connections are automatically handled for you. See the gateway's documentation for more information.

A Cache is also provided for you. This will be updated automatically for you as data is received from the Discord API via events. When calling a method on a Context, the cache will first be searched for relevant data to avoid unnecessary HTTP requests to the Discord API. For more information, see the cache's module-level documentation.

Note that - although this documentation will try to be as up-to-date and accurate as possible - Discord hosts official documentation. If you need to be sure that some information piece is accurate, refer to their docs.

Example Bot

A basic ping-pong bot looks like:

use std::env;

use serenity::async_trait;
use serenity::prelude::*;
use serenity::model::channel::Message;
use serenity::framework::standard::macros::{command, group};
use serenity::framework::standard::{StandardFramework, CommandResult};

#[group]
#[commands(ping)]
struct General;

struct Handler;

#[async_trait]
impl EventHandler for Handler {}

#[tokio::main]
async fn main() {
    let framework = StandardFramework::new()
        .configure(|c| c.prefix("~")) // set the bot's prefix to "~"
        .group(&GENERAL_GROUP);

    // Login with a bot token from the environment
    let token = env::var("DISCORD_TOKEN").expect("token");
    let intents = GatewayIntents::non_privileged() | GatewayIntents::MESSAGE_CONTENT;
    let mut client = Client::builder(token, intents)
        .event_handler(Handler)
        .framework(framework)
        .await
        .expect("Error creating client");

    // start listening for events by starting a single shard
    if let Err(why) = client.start().await {
        println!("An error occurred while running the client: {:?}", why);
    }
}

#[command]
async fn ping(ctx: &Context, msg: &Message) -> CommandResult {
    msg.reply(ctx, "Pong!").await?;

    Ok(())
}

Full Examples

Full examples, detailing and explaining usage of the basic functionality of the library, can be found in the examples directory.

Installation

Add the following to your Cargo.toml file:

[dependencies]
serenity = "0.11"

MSRV Policy

Serenity's minimum supported Rust version (MSRV) is Rust 1.53.

We opt to keep MSRV stable on the current branch. This means it will remain unchanged between minor releases. Occasionally, dependencies may violate SemVer and update their own MSRV in a breaking way. As a result, pinning their versions will become necessary to successfully build Serenity using an older Rust release. (NOTE: This is currently the case; building using Rust 1.53 requires pinning dashmap = "=5.2.0", indexmap = "=1.8.2", and time = "=0.3.9". If the simd_json feature is enabled, you must additionally pin halfbrown = "=0.1.12" and value-trait = "=0.2.10". Without dependency pinning, the de facto MSRV is Rust 1.59.)

The next branch tracks the latest Rust release as its MSRV. This allows for swift development as new languages features are stabilized, and reduces technical debt in the long run. When a new major release is cut, the MSRV on current will be updated to that of next, and we will commit to supporting that MSRV until the following major release.

Features

Features can be enabled or disabled by configuring the library through Cargo.toml:

[dependencies.serenity]
default-features = false
features = ["pick", "your", "feature", "names", "here"]
version = "0.11"

The default features are: builder, cache, client, framework, gateway, http, model, standard_framework, utils, and rustls_backend.

There are these alternative default features, they require to set default-features = false:

default_native_tls: Uses native_tls_backend instead of the default rustls_backend.
default_no_backend: Excludes the default backend, pick your own backend instead.

If you are unsure which to pick, use the default features by not setting default-features = false.

The following is a full list of features:

builder: The builders used in conjunction with models' methods.
cache: The cache will store information about guilds, channels, users, and other data, to avoid performing REST requests. If you are low on RAM, do not enable this.
collector: A collector awaits events, such as receiving a message from a user or reactions on a message, and allows for responding to the events in a convenient fashion. Collectors can be configured to enforce certain criteria the events must meet.
client: A manager for shards and event handlers, abstracting away the work of handling shard events and updating the cache, if enabled.
framework: Enables the framework, which is a utility to allow simple command parsing, before/after command execution, prefix setting, and more.
gateway: A Shard, used as a higher-level interface for communicating with the Discord gateway over a WebSocket client.
http: Functions providing a wrapper over Discord's REST API at a low enough level that optional parameters can be provided at will via a JsonMap.
model: Method implementations for models, acting as helper methods over the HTTP functions.
standard_framework: A standard, default implementation of the Framework
time: Use the time crate for Discord's timestamp fields. See serenity::model::Timestamp.
utils: Utility functions for common use cases by users.
voice: Enables registering a voice plugin to the client, which will handle actual voice connections from Discord. lavalink-rs or Songbird are recommended voice plugins.
default_native_tls: Default features but using native_tls_backend instead of rustls_backend.
absolute_ratelimits: Whether the library should use your system clock to avoid ratelimits, or use the interval given by Discord that might be less efficient due to latency in the network. If you turn this feature on, it is recommended to synchronise your clock with an NTP server (such as Google's).
tokio_task_builder: Enables tokio's tracing feature and uses tokio::task::Builder to spawn tasks with names if RUSTFLAGS="--cfg tokio_unstable" is set.
unstable_discord_api: Enables features of the Discord API that do not have a stable interface. The features might not have official documentation or are subject to change.
simd_json: Enables SIMD accelerated JSON parsing and rendering for API calls, use with RUSTFLAGS="-C target-cpu=native"
temp_cache: Enables temporary caching in functions that retrieve data via the HTTP API.

Serenity offers two TLS-backends, rustls_backend by default, you need to pick one if you do not use the default features:

rustls_backend: Uses Rustls for all platforms, a pure Rust TLS implementation.
native_tls_backend: Uses SChannel on Windows, Secure Transport on macOS, and OpenSSL on other platforms.

If you want all of the default features except for cache for example, you can list all but that:

[dependencies.serenity]
default-features = false
features = [
    "builder",
    "chrono",
    "client",
    "framework",
    "gateway",
    "http",
    "model",
    "standard_framework",
    "utils",
    "rustls_backend",
]
version = "0.11"

Dependencies

If you use the native_tls_backend and you are not developing on macOS or Windows, you will need:

openssl

Hosting

If you want a quick and easy way to host your bot, you can use shuttle, a Rust-native cloud development platform that allows deploying Serenity bots for free.

Projects extending Serenity

lavalink-rs: An interface to Lavalink and Andesite, an audio sending node based on Lavaplayer
Songbird: An async Rust library for the Discord voice API.
Poise: Experimental command framework, with advanced features like edit tracking, single function slash and prefix commands and flexible argument parsing.

mdjarv / serenity