Telega

A Gleam library for the Telegram Bot API on BEAM.

It provides

• an interface to the Telegram Bot HTTP-based APIs telega/api
• an client for the Telegram Bot API telega/client
• adapter to use with wisp
• polling implementation
• session bot implementation
• conversation implementation
• convenient utilities for common tasks

Quick start

If you are new to Telegram bots, read the official Introduction for Developers written by the Telegram team.

First, visit @BotFather to create a new bot. Copy the token and save it for later.

Initiate a gleam project and add telega as a dependencies:

$ gleam new first_tg_bot
$ cd first_tg_bot
$ gleam add telega

Replace the first_tg_bot.gleam file content with the following code:

import telega
import telega/polling
import telega/reply
import telega/router
import telega/update

fn handle_text(ctx, text) {
  use ctx <- telega.log_context(ctx, "echo_text")
  let assert Ok(_) = reply.with_text(ctx, text)
  Ok(ctx)
}

fn handle_command(ctx, command: update.Command) {
  use ctx <- telega.log_context(ctx, "echo_command")
  let assert Ok(_) = reply.with_text(ctx, "Command: " <> command.text)
  Ok(ctx)
}

pub fn main() {
  let router =
    router.new("echo_bot")
    |> router.on_any_text(handle_text)
    |> router.on_commands(["start", "help"], handle_command)

  let assert Ok(bot) =
    telega.new_for_polling(token: "BOT_TOKEN")
    |> telega.with_router(router)
    |> telega.init_for_polling_nil_session()

  let assert Ok(poller) = polling.start_polling_default(bot)

  polling.wait_finish(poller)
}

Replace "BOT_TOKEN" with the token you received from the BotFather. Then run the bot:

$ gleam run

And it will echo all received text messages.

Congratulations! You just wrote a Telegram bot :)

Examples

Other examples can be found in the examples directory.

Development

gleam run   # Run the project
gleam test  # Run the tests
gleam shell # Run an Erlang shell