src/JWT.php
public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null)
    {
        $header = array('typ' => 'JWT', 'alg' => $alg);
        if ($keyId !== null) {
            $header['kid'] = $keyId;
        }
        if ( isset($head) && is_array($head) ) {
            $header = array_merge($head, $header);
        }
        $segments = array();
        $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($header));
        $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($payload));
        $signing_input = implode('.', $segments);

        $signature = JWT::sign($signing_input, $key, $alg);
        $segments[] = JWT::urlsafeB64Encode($signature);

        return implode('.', $segments);
    }
public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $head = null)
    {
        $header = array('typ' => 'JWT', 'alg' => $alg);
        if ($keyId !== null) {
            $header['kid'] = $keyId;
        }
        if ( isset($head) && is_array($head) ) {
            $header = array_merge($head, $header);
        }
        $segments = array();
        $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($header));
        $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($payload));
        $signing_input = implode('.', $segments);

        $signature = JWT::sign($signing_input, $key, $alg);
        $segments[] = JWT::urlsafeB64Encode($signature);

        return implode('.', $segments);
    }
Converts and signs a PHP object or array into a JWT string.

@param object|array  $payload    PHP object or array
@param string        $key        The secret key.
If the algorithm used is asymmetric, this is the private key
@param string        $alg        The signing algorithm.
Supported algorithms are 'HS256', 'HS384', 'HS512' and 'RS256'
@param array         $head       An array with header elements to attach

@return string A signed JWT

@uses jsonEncode
@uses urlsafeB64Encode