Golang Telegram Bot

✅ Present in the list of libraries https://core.telegram.org/bots/samples#go

Telegram Group

Supports Bot API version: 7.3 from May 6, 2024

It's a Go zero-dependencies telegram bot framework

A simple example echo-bot:

package main

import (
	"context"
	"os"
	"os/signal"

	bot "github.com/gokhanaltun/go-telegram-bot"
	"github.com/gokhanaltun/go-telegram-bot/models"
)

// Send any text message to the bot after the bot has been started

func main() {
	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
	defer cancel()

	opts := []bot.Option{
		bot.WithDefaultHandler(handler),
	}

	b, err := bot.New("YOUR_BOT_TOKEN_FROM_BOTFATHER", opts...)
	if err != nil {
		panic(err)
	}

	b.Start(ctx)
}

func handler(ctx context.Context, b *bot.Bot, update *models.Update) {
	b.SendMessage(ctx, &bot.SendMessageParams{
		ChatID: update.Message.Chat.ID,
		Text:   update.Message.Text,
	})
}

You can find more examples in the examples folder.

For test examples, you should set environment variable EXAMPLE_TELEGRAM_BOT_TOKEN to your bot token.

Getting started

Go version: 1.18

Install the dependencies:

go get -u github.com/gokhanaltun/go-telegram-bot

Initialize and run the bot:

b, err := bot.New("YOUR_BOT_TOKEN_FROM_BOTFATHER")

b.Start(context.TODO())

On create bot will call the getMe method (with 5 sec timeout). And returns error on fail. If you want to change this timeout, use option bot.WithCheckInitTimeout

You can to define default handler for the bot:

b, err := bot.New("YOUR_BOT_TOKEN_FROM_BOTFATHER", bot.WithDefaultHandler(handler))

func handler(ctx context.Context, b *bot.Bot, update *models.Update) {
	// this handler will be called for all updates
}

Webhooks

If you want to use webhooks, instead bot.Start you should use bot.StartWebhook method for start the bot. Also, you should to use bot.WebhookHandler() method as http handler for your server.

func main() {
	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
	defer cancel()

	opts := []bot.Option{
		bot.WithDefaultHandler(handler),
	}

	b, _ := bot.New(os.Getenv("EXAMPLE_TELEGRAM_BOT_TOKEN"), opts...)

	// call methods.SetWebhook if needed
	
	go b.StartWebhook(ctx)

	http.ListenAndServe(":2000", b.WebhookHandler())

	// call methods.DeleteWebhook if needed
}

func handler(ctx context.Context, b *bot.Bot, update *models.Update) {
	b.SendMessage(ctx, &bot.SendMessageParams{
		ChatID: update.Message.Chat.ID,
		Text:   update.Message.Text,
	})
}

Demo in examples

Also, you can manually process updates with bot.ProcessUpdate method.

update := models.Update{}

json.NewDecoder(req.Body).Decode(&update)

b.ProcessUpdate(ctx, &update)

Middlewares

You can use middlewares with WithMiddlewares(middlewares ...Middleware) option.

See an example in examples

Available methods

All available methods are listed in the Telegram Bot API documentation

You can use all these methods as bot funcs. All methods have name like in official documentation, but with capital first letter.

bot.SendMessage, bot.GetMe, bot.SendPhoto, etc

All methods have signature (ctx context.Context, params <PARAMS>) (<response>, error). Except GetMe, Close and Logout which are have not params

<PARAMS> is a struct with fields that corresponds to Telegram Bot API parameters. All Params structs have name like for corresponded methods, but with Params suffix.

SendMessageParams for SendMessage method etc.

You should pass params by pointer

bot.SendMessage(ctx, &bot.SendMessageParams{...})

Options

You can use options to customize the bot.

b, err := bot.New("YOUR_BOT_TOKEN_FROM_BOTFATHER", opts...)

Options list (see options.go for more details)

• WithCheckInitTimeout(timeout time.Duration) - timeout for check init bot
• WithMiddlewares(middlewares ...Middleware) - add middlewares
• WithMessageTextHandler(pattern string, matchType MatchType, handler HandlerFunc) - add handler for Message.Text field
• WithCallbackQueryDataHandler(pattern string, matchType MatchType, handler HandlerFunc) - add handler for CallbackQuery.Data field
• WithDefaultHandler(handler HandlerFunc) - add default handler
• WithDebug() - enable debug mode
• WithErrorsHandler(handler ErrorsHandler) - add errors handler
• WithDebugHandler(handler DebugHandler) - add debug handler
• WithHTTPClient(pollTimeout time.Duration, client HttpClient) - set custom http client
• WithServerURL(serverURL string) - set server url
• WithSkipGetMe() - skip call GetMe on bot init
• WithAllowedUpdates(params AllowedUpdates) - set allowed_updates for getUpdates method
• WithUpdatesChannelCap(cap int) - set updates channel capacity, by default 1024

Message.Text and CallbackQuery.Data handlers

For your convenience, you can use Message.Text and CallbackQuery.Data handlers.

An example:

b, err := bot.New("YOUR_BOT_TOKEN_FROM_BOTFATHER")

b.RegisterHandler(bot.HandlerTypeMessageText, "/start", bot.MatchTypeExact, myStartHandler)

b.Start(context.TODO())

also you can use bot init options WithMessageTextHandler and WithCallbackQueryDataHandler

In this example, the handler will be called when the user sends /start message. All other messages will be handled by the default handler.

Handler Types:

• HandlerTypeMessageText - for Update.Message.Text field
• HandlerTypeCallbackQueryData - for Update.CallbackQuery.Data field

RegisterHandler returns a handler ID string. You can use it to remove the handler later.

b.UnregisterHandler(handlerID)

Match Types:

• MatchTypeExact
• MatchTypePrefix
• MatchTypeContains

You can use RegisterHandlerRegexp to match by regular expression.

re := regexp.MustCompile(`^/start`)

b.RegisterHandlerRegexp(bot.HandlerTypeMessageText, re, myStartHandler)

If you want to use custom handler, use RegisterHandlerMatchFunc

matchFunc := func(update *models.Update) bool {
	// your checks
	return true
}

b.RegisterHandlerMatchFunc(bot.HandlerTypeMessageText, matchFunc, myHandler)

InputFile

For some methods, like SendPhoto, SendAudio etc, you can send file by file path or file contents.

For send file by URL or FileID, you can use &models.InputFileString{Data: string}:

// file id of uploaded image 
inputFileData := "AgACAgIAAxkDAAIBOWJimnCJHQJiJ4P3aasQCPNyo6mlAALDuzEbcD0YSxzjB-vmkZ6BAQADAgADbQADJAQ"
// or URL image path
// inputFileData := "https://example.com/image.png"

params := &bot.SendPhotoParams{
    ChatID:  chatID,
    Photo:   &models.InputFileString{Data: inputFileData},
}

bot.SendPhoto(ctx, params)

Demo in examples

For send image file by file contents, you can use &models.InputFileUpload{Filename: string, Data: io.Reader}:

fileContent, _ := os.ReadFile("/path/to/image.png")

params := &bot.SendPhotoParams{
    ChatID:  chatID,
    Photo:   &models.InputFileUpload{Filename: "image.png", Data: bytes.NewReader(fileContent)},
}

bot.SendPhoto(ctx, params)

Demo in examples

InputMedia

For methods like SendMediaGroup or EditMessageMedia you can send media by file path or file contents.

Official documentation InputMedia

field media: File to send. Pass a file_id to send a file that exists on the Telegram servers (recommended), pass an HTTP URL for Telegram to get a file from the Internet, or pass “attach://<file_attach_name>” to upload a new one using multipart/form-data under <file_attach_name> name.

If you want to use attach:// format, you should to define MediaAttachment field with file content reader.

fileConetent, _ := os.ReadFile("/path/to/image.png")

media1 := &models.InputMediaPhoto{
	Media: "https://telegram.org/img/t_logo.png",
}

media2 := &models.InputMediaPhoto{
	Media: "attach://image.png", 
	Caption: "2",
	MediaAttachment: bytes.NewReader(fileConetent),
}

params := &bot.SendMediaGroupParams{
    ChatID: update.Message.Chat.ID,
    Media: []models.InputMedia{
        media1,
        media2,
    },
}

bot.SendMediaGroup(ctx, params)

Demo in examples

Helpers

EscapeMarkdown(s string) string

Escape special symbols for Telegram MarkdownV2 syntax

EscapeMarkdownUnescaped(s string) string

Escape only unescaped special symbols for Telegram MarkdownV2 syntax

RandomString(n int) string

Returns fast random a-zA-Z string with n length

True() bool, False() bool

Allows you to define *bool values for params, which require *bool, like SendPoolParams

p := &bot.SendPollParams{
    ChatID: chatID,
    Question: "Question",
    Options: []string{"Option 1", "Option 2"},
    IsAnonymous: bot.False(),
}

b.SendPool(ctx, p)

FileDownloadLink(f *models.File) string

Return file download link after call method GetFile

See [documentation(https://core.telegram.org/bots/api#getfile)

Errors

This library includes error handling. It provides the following error types:

• ErrorForbidden (403): This error occurs when the bot has no access to the action, such as when the user has blocked the bot.
• ErrorBadRequest (400): This error indicates a bad request made to the bot's API.
• ErrorUnauthorized (401): This error occurs when the bot's access is unauthorized for the requested action.
• TooManyRequestsError: (429) This error indicates that the bot has received too many requests within a short period. It includes a RetryAfter value indicating when to retry the request.
• ErrorNotFound (404): This error indicates that the requested resource was not found.
• ErrorConflict (409): This error indicates a conflict occurred during the request.

Usage:

_, err := b.SendMessage(...)

if errors.Is(err, mybot.ErrorForbidden) {
    // Handle the ErrorForbidden (403) case here
}

if errors.Is(err, mybot.ErrorBadRequest) {
    // Handle the ErrorBadRequest (400) case here
}

if errors.Is(err, mybot.ErrorUnauthorized) {
    // Handle the ErrorUnauthorized (401) case here
}

if mybot.IsTooManyRequestsError(err) {
    // Handle the TooManyRequestsError (429) case here
    fmt.Println("Received TooManyRequestsError with retry_after:", err.(*mybot.TooManyRequestsError).RetryAfter)
}

if errors.Is(err, mybot.ErrorNotFound) {
    // Handle the ErrorNotFound (404) case here
}

if errors.Is(err, mybot.ErrorConflict) {
    // Handle the ErrorConflict (409) case here
}

UI Components

In the repo https://github.com/go-telegram/ui you can find a some UI elements for your bot.

• datepicker
• inline_keyboard
• slider
• paginator

and more...

Please, check the repo for more information and live demo.