get chatid with php

[DeAref]

How to get Telegram.WebApp.initDataUnsafe > chat_id with php not js

[revenkroz]

You can get chatId when person starting bot for the first time — just take it from Update object. If you missed it you can send xhr-request with initData from frontend (web app) to some special endpoint like this:

fetch('/your-special-endpoint-to-recieve-data', {
    method: 'POST',
    body: Telegram.WebApp.initData, // data from telegram
})
``

[revenkroz]

Telegram did a really great feature to confirm if this action is from specific user or not. You can validate it (read more)

In PHP it will be something like this:

// $data is parsed data from Telegram
public function checkWebAppData(array $data): bool
{
    asort($data);
    $dataCheckString = [];
    foreach ($data as $key => $value) {
        if ($key === 'hash') {
            continue;
        }

        if (is_array($value)) {
            $dataCheckString[] = $key . '=' . json_encode($value);
        } else {
            $dataCheckString[] = $key . '=' . $value;
        }
    }

    $dataCheckString = implode("\n", $dataCheckString);
    $secretKey = hash_hmac('sha256', 'YOUR-TOKEN-CODE-123', 'WebAppData', true);
    $sig = hash_hmac('sha256', $dataCheckString, $secretKey);

    return $sig === $data['hash'];
}

Function will return true if data is valid. This way you can get user ($data['user']) and trust it.

// $initDataFromTelegram is raw data (string) received by your endpoint
parse_str($initDataFromTelegram, $data);

// check if it is valid
if (checkWebAppData($data) {
    // get user 
    $userData = json_decode($data['user'], true);
    // do something with it
    // ....
}

[revenkroz]

@DeAref if I answered your question, can I close discussion?

[DeAref]

I almost understand what you are saying, but there are still questions in my mind
Where do I get $initDataFromTelegram?
This is the same $update = json_decode(file_get_contents('php://input')); Is?
Do you have more example for this method?

[revenkroz]

Yes. It's almost the same, but without json_decode as we receive data not in json. You should parse raw data with parse_str. The data is Telegram.WebApp.initData sent from frontend.

[CrazyTapok-bit]

The above code should perform its function properly, but for a more reliable check and the ability to have user data in PHP, you can use the TgWebValid library, it contains all the necessary checks and gives a 100% guarantee of the result. Moreover, it will return all user data to you, I recommend you try it. Connection takes only one minute