teloxide

A full-featured framework that empowers you to easily build [Telegram bots](https://telegram.org/blog/bot-revolution) using the [`async`/`.await`](https://rust-lang.github.io/async-book/01_getting_started/01_chapter.html) syntax in [Rust](https://www.rust-lang.org/). It handles all the difficult stuff so you can focus only on your business logic.

Table of contents

Features

Getting started

  1. Create a new bot using @Botfather to get a token in the format 123456789:blablabla.
  2. Initialise the TELOXIDE_TOKEN environmental variable to your token: ```bash

    Unix

$ export TELOXIDE_TOKEN=

Windows

$ set TELOXIDE_TOKEN= 3. Be sure that you are up to date: bash

If you're using stable

$ rustup update stable $ rustup override set stable

If you're using nightly

$ rustup update nightly $ rustup override set nightly ```

  1. Execute cargo new my_bot, enter the directory and put these lines into your Cargo.toml: toml [dependencies] teloxide = "0.2.0" log = "0.4.8" tokio = "0.2.11" pretty_env_logger = "0.4.0"

The ping-pong bot

This bot has a single message handler, which answers "pong" to each incoming message:

(Full) ```rust use teloxide::prelude::*;

[tokio::main]

async fn main() { teloxide::enablelogging!(); log::info!("Starting pingpong_bot!");

let bot = Bot::from_env();

Dispatcher::new(bot)
    .messages_handler(|rx: DispatcherHandlerRx<Message>| {
        rx.for_each(|message| async move {
            message.answer("pong").send().await.log_on_error().await;
        })
    })
    .dispatch()
    .await;

}

```

Commands

Commands are defined similar to how we define CLI using structopt. This bot says "I am a cat! Meow!" on /meow, generates a random number within [0; 1) on /generate, and shows the usage guide on /help:

(Full) ```rust // Imports are omitted...

[derive(BotCommand)]

[command(rename = "lowercase", description = "These commands are supported:")]

enum Command { #[command(description = "display this text.")] Help, #[command(description = "be a cat.")] Meow, #[command(description = "generate a random number within [0; 1).")] Generate, }

fn generate() -> String { threadrng().genrange(0.0, 1.0).to_string() }

async fn answer( cx: DispatcherHandlerCx, command: Command, ) -> ResponseResult<()> { match command { Command::Help => cx.answer(Command::descriptions()).send().await?, Command::Generate => cx.answer(generate()).send().await?, Command::Meow => cx.answer("I am a cat! Meow!").send().await?, };

Ok(())

}

async fn handlecommands(rx: DispatcherHandlerRx) { // Only iterate through commands in a proper format: rx.commands::(panic!("Insert here your bot's name")) // Execute all incoming commands concurrently: .foreachconcurrent(None, |(cx, command, _)| async move { answer(cx, command).await.logon_error().await; }) .await; }

[tokio::main]

async fn main() { // Setup is omitted... } ```



See? The dispatcher gives us a stream of messages, so we can handle it as we want! Here we use our .commands::<Command>() and .for_each_concurrent(), but others are also available: - .flatten() - .left_stream() - .scan() - .skip_while() - .zip() - .select_next_some() - .fold() - .inspect() - ... And lots of others!

Guess a number

Wanna see more? This is a bot, which starts a game on each incoming message. You must guess a number from 1 to 10 (inclusively):

(Full) ```rust // Setup is omitted...

[derive(SmartDefault)]

enum Dialogue { #[default] Start, ReceiveAttempt(u8), }

async fn handlemessage( cx: DialogueDispatcherHandlerCx, ) -> ResponseResult> { match cx.dialogue { Dialogue::Start => { cx.answer( "Let's play a game! Guess a number from 1 to 10 (inclusively).", ) .send() .await?; next(Dialogue::ReceiveAttempt(threadrng().genrange(1, 11))) } Dialogue::ReceiveAttempt(secret) => match cx.update.text() { None => { cx.answer("Oh, please, send me a text message!").send().await?; next(cx.dialogue) } Some(text) => match text.parse::() { Ok(attempt) => match attempt { x if !(1..=10).contains(&x) => { cx.answer( "Oh, please, send me a number in the range [1; \ 10]!", ) .send() .await?; next(cx.dialogue) } x if x == secret => { cx.answer("Congratulations! You won!").send().await?; exit() } _ => { cx.answer("No.").send().await?; next(cx.dialogue) } }, Err() => { cx.answer( "Oh, please, send me a number in the range [1; 10]!", ) .send() .await?; next(cx.dialogue) } }, }, } }

[tokio::main]

async fn main() { // Setup is omitted... } ```



Our finite automaton, designating a user dialogue, cannot be in an invalid state, and this is why it is called "type-safe". We could use enum + Options instead, but it will lead is to lots of unpleasure .unwrap()s.

Remember that a classical finite automaton is defined by its initial state, a list of its possible states and a transition function? We can think that Dialogue is a finite automaton with a context type at each state (Dialogue::Start has (), Dialogue::ReceiveAttempt has u8).

See examples/dialogue_bot to see a bit more complicated bot with dialogues.

More examples!

Recommendations

The second one produces very strange compiler messages because of the #[tokio::main] macro. However, the examples in this README use the second variant for brevity.

FAQ

Where I can ask questions?

Issues is a good place for well-formed questions, for example, about the library design, enhancements, bug reports. But if you can't compile your bot due to compilation errors and need quick help, feel free to ask in our official group: https://t.me/teloxide.

Why Rust?

Most programming languages have their own implementations of Telegram bots frameworks, so why not Rust? We think Rust provides enough good ecosystem and the language itself to be suitable for writing bots.

Community bots

Feel free to push your own bot into our collection: https://github.com/teloxide/community-bots. Later you will be able to play with them right in our official chat: https://t.me/teloxide.

Contributing

See CONRIBUTING.md.