Generate GA4 custom report for specific path, event and timeframe using Google Analytics Data API

ga4-custom-report.md

This code example uses Laravel's Http client.

You need to generate the private key from your service account in a Google Cloud Platform project. Then grant access to your GA4 property to the service account client email.

There are some instructions for doing that in the JReviews Dashboard Addon documentation, which is where the code below comes from.

function getAuthToken($clientEmail, $privateKey)
{          
      $base64URLEncode = function($data) {
        return rtrim(strtr(base64_encode($data), '+/', '-_'), '=');
      };

      $header = $base64URLEncode(json_encode(['alg' => 'RS256', 'typ' => 'JWT']));

      $claim = $base64URLEncode(json_encode([
        'iss' => $clientEmail,
        'scope' => 'https://www.googleapis.com/auth/analytics.readonly',
        'aud' => 'https://www.googleapis.com/oauth2/v4/token',
        'iat' => time(),
        'exp' => time() + (60 * 60),
      ]));

      $privateKeyId = openssl_pkey_get_private($privateKey);

      openssl_sign($header.'.'.$claim, $signature, $privateKeyId, "sha256");

      $jwt = $header.'.'.$claim.'.'.$base64URLEncode($signature);

      $response = \Http::post('https://www.googleapis.com/oauth2/v4/token', [
        'grant_type' => 'urn:ietf:params:oauth:grant-type:jwt-bearer',
        'assertion' => $jwt,
      ]);

      if ($response->ok()) {
        return $response->json()['access_token'];
      }

      return false;
  }
}

$res = \Http::withToken(getAuthToken($clientEmail, $privateKey))
    ->post('https://analyticsdata.googleapis.com/v1beta/properties/YOUR-GA4-PROPERTY-ID:runReport', [
          'keepEmptyRows' => true,
          'dateRanges' => [
              'startDate' => '2022-12-01',
              'endDate' => '2022-12-31',
          ],
          'dimensions' => [
              ['name' => 'eventName'],
              ['name' => 'date'],
          ],
          'metrics' => [
              ['name' => 'eventCount'],
              ['name' => 'sessions']
          ],
          'orderBys' => [
              'dimension' => [
                  'dimension_name' => 'date',
              ],
              'desc' => false,
          ],
          'dimensionFilter' => [
              'andGroup' => [
                  'expressions' => [
                      'filter' => [
                          'fieldName' => 'pagePath',
                          'stringFilter' => [
                            'value' => '/url-path',
                            'matchType' => 'EXACT'
                          ]
                      ],
                      'filter' => [
                        'fieldName' => 'eventName',
                        'stringFilter' => [
                          'value' => 'contact_click',
                          'matchType' => 'EXACT'
                        ],
                      ],

                  ]
              ]
          ]
]);

$res->json();