# Getting Started

Add go-bot to a Go module and run a minimal echo bot on one platform.

## Prerequisites

| Item | Requirement |
|---|---|
| Go | 1.25.0 or later (`go.mod`) |
| Telegram | Bot token from BotFather |
| Discord | Bot token, with **Message Content Intent** enabled in the Developer Portal |
| LINE | Channel secret, long-lived channel access token, and a public HTTPS URL that forwards to your webhook port |

Telegram and Discord connect outbound, so they run behind NAT. LINE pushes events to your server, so it needs an inbound HTTPS endpoint (a reverse proxy such as ngrok works for local testing).

## Install

```bash
go get github.com/pardnchiu/go-bot@latest
```

Import only the platform packages you use:

```go
import (
    "github.com/pardnchiu/go-bot/core/telegram"
    "github.com/pardnchiu/go-bot/core/discord"
    "github.com/pardnchiu/go-bot/core/line"
)
```

## Minimal echo bot

Every platform follows the same order: `New`, `Reply`, `Start`, then `Close` on shutdown. The handler's non-empty return is sent back as a reply.

```go
package main

import (
    "context"
    "log"
    "os"
    "os/signal"
    "syscall"

    "github.com/pardnchiu/go-bot/core/telegram"
)

func main() {
    bot, err := telegram.New(os.Getenv("TELEGRAM_TOKEN"))
    if err != nil {
        log.Fatal(err)
    }
    bot.Reply(func(ctx context.Context, in telegram.Input) string {
        return "you said: " + in.Text
    })

    ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
    defer stop()
    if err := bot.Start(ctx); err != nil {
        log.Fatal(err)
    }
    <-ctx.Done()
    bot.Close()
}
```

The Discord and LINE versions change only the constructor and the `Input` type:

| Platform | Constructor | Handler input |
|---|---|---|
| Telegram | `telegram.New(token)` | `telegram.Input` |
| Discord | `discord.New(token)` | `discord.Input` |
| LINE | `line.New(secret, token, "8080")` | `line.Input` |

The library does not read environment variables; the variable names above belong to your program.

## Next steps

- [Bot Lifecycle](/core-concepts) — what `Start` validates and how `Close` shuts down
- [Reply Handler](/reply-handler) — where replies go and what happens on panic
- Platform setup: [Telegram](/telegram), [Discord](/discord), [LINE](/line)