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.

Higher-order design

teloxide supports higher-order programming by making streams a first-class citizen: feel free to (de)multiplex them, apply arbitrary transformations, pass to/return from other functions, lazily evaluate them, concurrently process their items, and much more, thereby achieving extremely flexible design.

Type safety

All the API types and methods are implemented with heavy use of ADTs to enforce type safety and tight integration with IDEs. Bot's commands have precise types too, thereby serving as a self-documenting code and respecting the parse, don't validate programming idiom.

Persistence

Dialogues management is independent of how/where they are stored: just replace one line and make them persistent (for example, store on a disk, transmit through a network), without affecting the actual FSM algorithm. By default, teloxide stores all user dialogues in RAM. Default database implementations are coming!

# 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 ``` 4. 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](https://github.com/teloxide/teloxide/blob/master/examples/ping_pong_bot/src/main.rs)) ```rust use teloxide::prelude::*; #[tokio::main] async fn main() { teloxide::enable_logging!(); log::info!("Starting ping_pong_bot!"); let bot = Bot::from_env(); Dispatcher::new(bot) .messages_handler(|rx: DispatcherHandlerRx| { 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](https://docs.rs/structopt/0.3.9/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](https://github.com/teloxide/teloxide/blob/master/examples/simple_commands_bot/src/main.rs)) ```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 { thread_rng().gen_range(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 handle_commands(rx: DispatcherHandlerRx) { // Only iterate through commands in a proper format: rx.commands::(panic!("Insert here your bot's name")) // Execute all incoming commands concurrently: .for_each_concurrent(None, |(cx, command, _)| async move { answer(cx, command).await.log_on_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::()` and [`.for_each_concurrent()`](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html#method.for_each_concurrent), but others are also available: - [`.filter()`](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html#method.filter) / [`.filter_map()`](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html#method.filter_map) to filter certain kinds of updates; - [`.inspect()`](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html#method.inspect) for debugging purposes; - [`.for_each_concurrent()`](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html#method.for_each_concurrent) + [`tokio::sync::watch`](https://docs.rs/tokio/0.2.13/tokio/sync/watch/index.html) to register multiple handlers; - [`.text_messages()`](https://docs.rs/teloxide/0.2.0/teloxide/dispatching/trait.DispatcherHandlerRxExt.html#tymethod.text_messages) to receive only text messages; - ... And lots of [others](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html) and [others](https://docs.rs/teloxide/latest/teloxide/dispatching/trait.DispatcherHandlerRxExt.html) and [others](https://docs.rs/tokio/0.2.13/tokio/sync/index.html)! ## 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](https://github.com/teloxide/teloxide/blob/master/examples/guess_a_number_bot/src/main.rs)) ```rust // Imports are omitted... #[derive(SmartDefault)] enum Dialogue { #[default] Start, ReceiveAttempt(u8), } type Cx = DialogueDispatcherHandlerCx; type Res = ResponseResult>; async fn start(cx: Cx<()>) -> Res { cx.answer("Let's play a game! Guess a number from 1 to 10 (inclusively).") .send() .await?; next(Dialogue::ReceiveAttempt(thread_rng().gen_range(1, 11))) } async fn receive_attempt(cx: Cx) -> Res { let secret = cx.dialogue; match cx.update.text() { None => { cx.answer("Oh, please, send me a text message!").send().await?; next(Dialogue::ReceiveAttempt(secret)) } Some(text) => match text.parse::() { Ok(attempt) => { if attempt == secret { cx.answer("Congratulations! You won!").send().await?; exit() } else { cx.answer("No.").send().await?; next(Dialogue::ReceiveAttempt(secret)) } } Err(_) => { cx.answer("Oh, please, send me a number in the range [1; 10]!") .send() .await?; next(Dialogue::ReceiveAttempt(secret)) } }, } } async fn handle_message( cx: DialogueDispatcherHandlerCx, ) -> Res { // Match is omitted... } #[tokio::main] async fn main() { // Setup is omitted... } ```

Our [finite automaton](https://en.wikipedia.org/wiki/Finite-state_machine), designating a user dialogue, cannot be in an invalid state, and this is why it is called "type-safe". We could use `enum` + `Option`s instead, but it would lead us to lots of unpleasant `.unwrap()`s. Remember that a classical [finite automaton](https://en.wikipedia.org/wiki/Finite-state_machine) 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](https://github.com/teloxide/teloxide/blob/master/examples/dialogue_bot/src/main.rs) to see a bit more complicated bot with dialogues. ## [More examples!](https://github.com/teloxide/teloxide/tree/master/examples) ## Recommendations - Use this pattern: ```rust #[tokio::main] async fn main() { run().await; } async fn run() { // Your logic here... } ``` Instead of this: ```rust #[tokio::main] async fn main() { // Your logic here... } ``` 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](https://github.com/teloxide/teloxide/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. ### Can I use webhooks? teloxide doesn't provide special API for working with webhooks due to their nature with lots of subtle settings. Instead, you setup your webhook by yourself, as shown in [webhook_ping_pong_bot](examples/webhook_ping_pong_bot/src/main.rs). Associated links: - [Marvin's Marvellous Guide to All Things Webhook](https://core.telegram.org/bots/webhooks) - [Using self-signed certificates](https://core.telegram.org/bots/self-signed) ### Can I use different loggers? Of course, you can. The [`enable_logging!`](https://docs.rs/teloxide/latest/teloxide/macro.enable_logging.html) and [`enable_logging_with_filter!`](https://docs.rs/teloxide/latest/teloxide/macro.enable_logging_with_filter.html) macros are just convenient utilities, not necessary to use them. You can setup a different logger, for example, [fern](https://crates.io/crates/fern), as usual, e.g. teloxide has no specific requirements as it depends only on [log](https://crates.io/crates/log). ## 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](https://github.com/teloxide/teloxide/blob/master/CONTRIBUTING.md).