Preventing duplicate responses from my Telegram bot

Other Questions Telegram bot
1

I’m having trouble with my Telegram bot. It keeps responding to the same message over and over. How can I fix this? The bot gets data from /getupdates. I think I need some kind of flag to show a reply was sent, but I’m not sure how to do it. Here’s a simplified version of my code:

<?php
$bot_key = '1234567890:ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghij';
$api_url = 'https://api.telegram.org/bot' . $bot_key;

$messages = file_get_contents($api_url . '/getUpdates');
$data = json_decode($messages, true);

$last_message = end($data['result']);
$user_id = $last_message['message']['from']['id'];
$message_text = $last_message['message']['text'];

if ($message_text == 'hello') {
    send_message($user_id, 'Hi there!');
} elseif ($message_text == 'goodbye') {
    send_message($user_id, 'See you later!');
}

function send_message($chat_id, $text) {
    global $api_url;
    file_get_contents($api_url . '/sendMessage?chat_id=' . $chat_id . '&text=' . urlencode($text));
}
?>

This code runs every minute. How can I stop it from replying to the same message multiple times?

2

Implementing an offset mechanism is an effective means to avoid duplicate responses. Rather than processing the same message several times, you can store the highest update_id you have handled. In subsequent calls to getUpdates, include an offset parameter set to this stored update_id plus one, ensuring that only new messages are retrieved. Persisting this offset value, for instance in a file or database, between script executions is important to maintain consistency. Below is an example illustrating this approach:

$offset = 0;
$messages = file_get_contents($api_url . '/getUpdates?offset=' . $offset);
$data = json_decode($messages, true);
if (!empty($data['result'])) {
    $last_update = end($data['result']);
    $offset = $last_update['update_id'] + 1;
    // Process new messages here
}
3

As someone who’s worked with Telegram bots, I’ve encountered this issue before. The key is to track which messages you’ve already processed. Here’s what worked for me:

Store the last processed update_id in a file or database. At the start of your script, read this value and use it as the offset in your getUpdates call. After processing messages, update this stored value.

Also, consider using long polling instead of running your script every minute. It’s more efficient and reduces the chances of missing messages. You can do this by adding a timeout parameter to your getUpdates call.

Lastly, error handling is crucial. Sometimes the Telegram API can be flaky, so make sure to catch and log any exceptions to avoid breaking your bot’s functionality.

4

yo, i had this problem too. wat worked for me was using the ‘offset’ parameter when u call getUpdates. like this:

$offset = get_last_offset(); // from file or db
$messages = file_get_contents($api_url . ‘/getUpdates?offset=’ . $offset);

then update ur offset after processing. it’ll stop the dupe responses!