Generate first-party device IDs

Adobe Experience Cloud applications have traditionally generated cookies to store device ids using different technologies, including:

Recent browser changes restrict the duration of these types of cookies. First-party cookies are most effective when they are set using a customer-owned server using a DNS A/AAAA-record as opposed to a DNS CNAME. The first-party device ID (FPID) functionality allows customers implementing Adobe Experience Platform Web SDK to use device IDs in cookies from servers using DNS A/AAAA-records. These IDs can then be sent to Adobe and used as seeds to generate Experience Cloud IDs (ECIDs), which remains the primary identifier in Adobe Experience Cloud applications.

Here is a quick example of how the functionality works:

For this tutorial, a specific example using the PHP scripting language is used to show how to:

Further documentation related to first-party device IDs can be found in the product documentation.

Generate a UUIDv4

PHP does not have a native library for UUID generation, so these code examples are more extensive than what would likely be required if another programming language was used. PHP was chosen for this example because it is a widely supported server-side language.

When the following function is called, it generates a random UUID version-4:

<?php

    function guidv4($data)
    {
        $data = $data ?? random_bytes(16);

        $data[6] = chr(ord($data[6]) & 0x0f | 0x40); // set version to 0100
        $data[8] = chr(ord($data[8]) & 0x3f | 0x80); // set bits 6-7 to 10

        return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
    }

?>

Write UUIDv4 value to a cookie

The following code makes a request to the function above to generate a UUID. It then sets the cookie flags decided upon by your organization. If a cookie has already been generated, then the expiration is extended.

<?php

    if(!isset($_COOKIE['FPID'])) {
        $cookie_value = guidv4(openssl_random_pseudo_bytes(16));
        $arr_cookie_options = array (
        'expires' => time() + 60*60*24*30*13,
        'path' => '/',
        'domain' => 'mysiteurl.com',
        'secure' => true,
        'httponly' => true,
        'samesite' => 'lax'
        );
        setcookie($cookie_name, $cookie_value, $arr_cookie_options);
        $_COOKIE[$cookie_name] = $cookie_value;
    }
    else {
        $cookie_value = $_COOKIE[$cookie_name];
        $arr_cookie_options = array (
        'expires' => time() + 60*60*24*30*13,
        'path' => '/',
        'domain' => 'mysiteurl.com',
        'secure' => true,
        'httponly' => true,
        'samesite' => 'lax'
        );
        setcookie($cookie_name, $cookie_value, $arr_cookie_options);
    }

?>

Include the Cookie Value in the Identity Map

The final step is to use PHP to echo the cookie value to the Identity Map.

{
    "identityMap": {
        "FPID": [
                    {
                        "id": "<? echo $_COOKIE[$cookie_name] ?>",
                        "authenticatedState": "ambiguous",
                        "primary": true
                    }
                ]
        }
}

Validate ECID generation

Validate the implementation by confirming that the same ECID is generated from your first-party device ID:

For more information about this feature, see the documentation.