Inline Mode Bot

In this example section, we will create a bot that supports Telegram's inline mode, allowing users to interact with the bot directly from any chat by typing @botusername query. This enables powerful features like instant content sharing, quick searches, and seamless bot interactions without leaving the current conversation.

We will use two different types of handlers:

onMessage for handling commands in private chats
onInline for handling inline queries from any chat

Import necessary classes

package io.github.natanimn;

import io.github.natanimn.telebof.BotClient;
import io.github.natanimn.telebof.enums.ParseMode;
import io.github.natanimn.telebof.types.inline.InlineQueryResult;
import io.github.natanimn.telebof.types.inline.InlineQueryResultArticle;
import io.github.natanimn.telebof.types.input.InputTextMessageContent;
import io.github.natanimn.telebof.types.keyboard.InlineKeyboardButton;
import io.github.natanimn.telebof.types.keyboard.InlineKeyboardMarkup;

Create InlineBot class and initialize BotClient with a token

public class InlineBot {
    public static void main(String[] args){
        final var TOKEN = System.getenv("TOKEN"); // Get bot token from environment variable
        final var bot = new BotClient(TOKEN); // Initialize bot client

        // Add handlers here

        bot.startPolling(); // Start the bot
    }
}

Our bot will be handling the following events:

/start command in private chat
Empty inline queries (when user just types @botusername)
Inline queries with text input

Create /start handler with inline button

When the user types /start in a private chat, the bot responds with a message containing a button that triggers inline mode.

bot.onMessage(filter -> filter.commands("start"), (context, message) -> {
    // Create an inline keyboard with a button that opens inline mode
    var keyboard = new InlineKeyboardMarkup(new InlineKeyboardButton[]{
            new InlineKeyboardButton("Inline").switchInlineQueryCurrentChat("")
    });

    // Send welcome message with the inline button
    context.sendMessage(message.chat.id, "Hi! I am an inline bot. Press the button below to try inline mode")
            .replyMarkup(keyboard) // Attach the inline keyboard
            .exec();
});

Explanation:

InlineKeyboardMarkup creates an inline keyboard that appears below the message
InlineKeyboardButton("Inline") creates a button with the specified text
.switchInlineQueryCurrentChat("") makes the button open inline mode in the current chat when pressed
The empty string "" means no pre-filled query text

Result:

Handle empty inline queries

This handler is triggered when a user types just the bot's username (@botusername) without any additional text.

bot.onInline(filter -> filter.emptyQuery(), (context, query) -> {
    // Create a result for empty queries
    var result = new InlineQueryResultArticle(
            "1", // Unique identifier for this result
            "Write something", // Title shown to the user
            new InputTextMessageContent("Write something") // Content that will be sent
    );

    // Send the result to the user
    context.answerInlineQuery(query.id, new InlineQueryResult[]{result}).exec();
});

Explanation:

filter.emptyQuery() matches when the user doesn't provide any search text
InlineQueryResultArticle creates a clickable result item
"1" is a unique ID for this result (Can be any string)
"Write something" is the title shown in the results list
InputTextMessageContent("Write something") is the message that will be sent if the user selects this result
answerInlineQuery() sends the results back to Telegram for display

Handle inline queries with text input

This handler processes inline queries where the user provides text after the bot's username (e.g., @botusername hello world).

bot.onInline(_ -> true, (context, query) -> {
    // Create a result that echoes the user's input
    var result = new InlineQueryResultArticle(
            "2", // Unique identifier
            query.query, // Title shows the user's query
            new InputTextMessageContent("<b>You said:</b> " + query.query).parseMode(ParseMode.HTML)
    ).description("Click here"); // Optional description below the title

    // Send the result
    context.answerInlineQuery(query.id, new InlineQueryResult[]{result}).exec();
});

Explanation:

_ -> true acts as a catch all for all inline queries (after the empty query handler)
query.query contains the text the user typed after the bot's username
InputTextMessageContent() creates formatted message content with HTML parsing
.description("Click here") adds a descriptive text below the title
The result shows the user's input and sends it back as a formatted message

User Experience: When users type @botusername some text, they see a result that says "some text" and can send a message saying "You said: some text".

Final Complete Code

public class InlineBot {
    public static void main(String[] args){
        final var TOKEN = System.getenv("TOKEN");
        final var bot = new BotClient(TOKEN);

        // Handle /start command with inline button
        bot.onMessage(filter -> filter.commands("start"), (context, message) -> {
            var keyboard = new InlineKeyboardMarkup(new InlineKeyboardButton[]{
                    new InlineKeyboardButton("Try Inline Mode").switchInlineQueryCurrentChat("")
            });
            context.sendMessage(message.chat.id, "Hi! I am an inline bot. Press the button below to try inline mode")
                    .replyMarkup(keyboard)
                    .exec();
        });

        // Handle empty inline queries (@botusername without text)
        bot.onInline(filter -> filter.emptyQuery(), (context, query) -> {
            var result = new InlineQueryResultArticle(
                    "1",
                    "Write something",
                    new InputTextMessageContent("Write something")
            );
            context.answerInlineQuery(query.id, new InlineQueryResult[]{result}).exec();
        });

        // Handle inline queries with text (@botusername some text)
        bot.onInline(_ -> true, (context, query) -> {
            var result = new InlineQueryResultArticle(
                    "2",
                    query.query,
                    new InputTextMessageContent("<b>You said:</b> " + query.query).parseMode(ParseMode.HTML)
            ).description("Click here");
            context.answerInlineQuery(query.id, new InlineQueryResult[]{result}).exec();
        });

        bot.startPolling();
    }
}

How Inline Mode Works

User types /start → Bot sends message with inline button
User presses button → Telegram opens inline mode in current chat
User types query → Bot receives inline query and returns results
User selects result → Bot's message is sent to the chat

Alternatively, users can directly type @botusername query in any chat to use inline mode.

The full source code can be found on examples/inline_bot