From be56a0ffe6c5fa87be64f49d77450c84c2db4d46 Mon Sep 17 00:00:00 2001
From: Jonathan Edey <145066863+jonathanedey@users.noreply.github.com>
Date: Mon, 4 Nov 2024 15:47:08 -0500
Subject: [PATCH] chore: Add `X-Goog-Api-Client` metric header to requests
 (#826)

---
 firebase_admin/_http_client.py   |   5 +
 firebase_admin/_utils.py         |   3 +
 firebase_admin/app_check.py      |   7 +-
 firebase_admin/storage.py        |   7 +-
 tests/test_auth_providers.py     | 190 +++++++++++++------------------
 tests/test_db.py                 | 118 ++++++++-----------
 tests/test_functions.py          |   4 +
 tests/test_http_client.py        |  14 ++-
 tests/test_instance_id.py        |  21 ++--
 tests/test_messaging.py          |  71 ++++++------
 tests/test_ml.py                 |  74 +++++-------
 tests/test_project_management.py |   5 +-
 tests/test_tenant_mgt.py         |  13 +++
 tests/test_user_mgt.py           |   2 +
 14 files changed, 255 insertions(+), 279 deletions(-)

diff --git a/firebase_admin/_http_client.py b/firebase_admin/_http_client.py
index d259faddf..f1eccbcf2 100644
--- a/firebase_admin/_http_client.py
+++ b/firebase_admin/_http_client.py
@@ -21,6 +21,7 @@
 import requests
 from requests.packages.urllib3.util import retry # pylint: disable=import-error
 
+from firebase_admin import _utils
 
 if hasattr(retry.Retry.DEFAULT, 'allowed_methods'):
     _ANY_METHOD = {'allowed_methods': None}
@@ -36,6 +37,9 @@
 
 DEFAULT_TIMEOUT_SECONDS = 120
 
+METRICS_HEADERS = {
+    'X-GOOG-API-CLIENT': _utils.get_metrics_header(),
+}
 
 class HttpClient:
     """Base HTTP client used to make HTTP calls.
@@ -72,6 +76,7 @@ def __init__(
 
         if headers:
             self._session.headers.update(headers)
+        self._session.headers.update(METRICS_HEADERS)
         if retries:
             self._session.mount('http://', requests.adapters.HTTPAdapter(max_retries=retries))
             self._session.mount('https://', requests.adapters.HTTPAdapter(max_retries=retries))
diff --git a/firebase_admin/_utils.py b/firebase_admin/_utils.py
index dcfb520d2..b6e292546 100644
--- a/firebase_admin/_utils.py
+++ b/firebase_admin/_utils.py
@@ -15,6 +15,7 @@
 """Internal utilities common to all modules."""
 
 import json
+from platform import python_version
 
 import google.auth
 import requests
@@ -75,6 +76,8 @@
     16: exceptions.UNAUTHENTICATED,
 }
 
+def get_metrics_header():
+    return f'gl-python/{python_version()} fire-admin/{firebase_admin.__version__}'
 
 def _get_initialized_app(app):
     """Returns a reference to an initialized App instance."""
diff --git a/firebase_admin/app_check.py b/firebase_admin/app_check.py
index 6bc10b2f4..e6b66efc1 100644
--- a/firebase_admin/app_check.py
+++ b/firebase_admin/app_check.py
@@ -51,6 +51,10 @@ class _AppCheckService:
     _scoped_project_id = None
     _jwks_client = None
 
+    _APP_CHECK_HEADERS = {
+        'X-GOOG-API-CLIENT': _utils.get_metrics_header(),
+    }
+
     def __init__(self, app):
         # Validate and store the project_id to validate the JWT claims
         self._project_id = app.project_id
@@ -62,7 +66,8 @@ def __init__(self, app):
                 'GOOGLE_CLOUD_PROJECT environment variable.')
         self._scoped_project_id = 'projects/' + app.project_id
         # Default lifespan is 300 seconds (5 minutes) so we change it to 21600 seconds (6 hours).
-        self._jwks_client = PyJWKClient(self._JWKS_URL, lifespan=21600)
+        self._jwks_client = PyJWKClient(
+            self._JWKS_URL, lifespan=21600, headers=self._APP_CHECK_HEADERS)
 
 
     def verify_token(self, token: str) -> Dict[str, Any]:
diff --git a/firebase_admin/storage.py b/firebase_admin/storage.py
index f3948371c..46f5f6043 100644
--- a/firebase_admin/storage.py
+++ b/firebase_admin/storage.py
@@ -55,8 +55,13 @@ def bucket(name=None, app=None) -> storage.Bucket:
 class _StorageClient:
     """Holds a Google Cloud Storage client instance."""
 
+    STORAGE_HEADERS = {
+        'X-GOOG-API-CLIENT': _utils.get_metrics_header(),
+    }
+
     def __init__(self, credentials, project, default_bucket):
-        self._client = storage.Client(credentials=credentials, project=project)
+        self._client = storage.Client(
+            credentials=credentials, project=project, extra_headers=self.STORAGE_HEADERS)
         self._default_bucket = default_bucket
 
     @classmethod
diff --git a/tests/test_auth_providers.py b/tests/test_auth_providers.py
index a5716266c..48f38a011 100644
--- a/tests/test_auth_providers.py
+++ b/tests/test_auth_providers.py
@@ -21,6 +21,7 @@
 import firebase_admin
 from firebase_admin import auth
 from firebase_admin import exceptions
+from firebase_admin import _utils
 from tests import testutils
 
 ID_TOOLKIT_URL = 'https://identitytoolkit.googleapis.com/v2'
@@ -70,6 +71,11 @@ def _instrument_provider_mgt(app, status, payload):
         testutils.MockAdapter(payload, status, recorder))
     return recorder
 
+def _assert_request(request, expected_method, expected_url):
+    assert request.method == expected_method
+    assert request.url == expected_url
+    assert request.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+    assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
 
 class TestOIDCProviderConfig:
 
@@ -110,9 +116,8 @@ def test_get(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}{1}'.format(USER_MGT_URLS['PREFIX'], '/oauthIdpConfigs/oidc.provider')
+        _assert_request(
+            recorder[0], 'GET', f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs/oidc.provider')
 
     @pytest.mark.parametrize('invalid_opts', [
         {'provider_id': None}, {'provider_id': ''}, {'provider_id': 'saml.provider'},
@@ -140,11 +145,9 @@ def test_create(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'POST'
-        assert req.url == '{0}/oauthIdpConfigs?oauthIdpConfigId=oidc.provider'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'POST',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?oauthIdpConfigId=oidc.provider')
+        got = json.loads(recorder[0].body.decode())
         assert got == self.OIDC_CONFIG_REQUEST
 
     def test_create_minimal(self, user_mgt_app):
@@ -165,11 +168,9 @@ def test_create_minimal(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'POST'
-        assert req.url == '{0}/oauthIdpConfigs?oauthIdpConfigId=oidc.provider'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'POST',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?oauthIdpConfigId=oidc.provider')
+        got = json.loads(recorder[0].body.decode())
         assert got == want
 
     def test_create_empty_values(self, user_mgt_app):
@@ -191,11 +192,9 @@ def test_create_empty_values(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'POST'
-        assert req.url == '{0}/oauthIdpConfigs?oauthIdpConfigId=oidc.provider'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'POST',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?oauthIdpConfigId=oidc.provider')
+        got = json.loads(recorder[0].body.decode())
         assert got == want
 
     @pytest.mark.parametrize('invalid_opts', [
@@ -225,13 +224,12 @@ def test_update(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'PATCH'
         mask = ['clientId', 'clientSecret', 'displayName', 'enabled', 'issuer',
                 'responseType.code', 'responseType.idToken']
-        assert req.url == '{0}/oauthIdpConfigs/oidc.provider?updateMask={1}'.format(
-            USER_MGT_URLS['PREFIX'], ','.join(mask))
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'PATCH',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs/oidc.provider?'
+                        f'updateMask={",".join(mask)}')
+        got = json.loads(recorder[0].body.decode())
         assert got == self.OIDC_CONFIG_REQUEST
 
     def test_update_minimal(self, user_mgt_app):
@@ -242,11 +240,10 @@ def test_update_minimal(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'PATCH'
-        assert req.url == '{0}/oauthIdpConfigs/oidc.provider?updateMask=displayName'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'PATCH',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs/oidc.provider?'
+                        f'updateMask=displayName')
+        got = json.loads(recorder[0].body.decode())
         assert got == {'displayName': 'oidcProviderName'}
 
     def test_update_empty_values(self, user_mgt_app):
@@ -258,12 +255,11 @@ def test_update_empty_values(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'PATCH'
         mask = ['displayName', 'enabled', 'responseType.idToken']
-        assert req.url == '{0}/oauthIdpConfigs/oidc.provider?updateMask={1}'.format(
-            USER_MGT_URLS['PREFIX'], ','.join(mask))
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'PATCH',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs/oidc.provider?'
+                        f'updateMask={",".join(mask)}')
+        got = json.loads(recorder[0].body.decode())
         assert got == {'displayName': None, 'enabled': False, 'responseType': {'idToken': False}}
 
     @pytest.mark.parametrize('provider_id', INVALID_PROVIDER_IDS + ['saml.provider'])
@@ -279,9 +275,8 @@ def test_delete(self, user_mgt_app):
         auth.delete_oidc_provider_config('oidc.provider', app=user_mgt_app)
 
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'DELETE'
-        assert req.url == '{0}{1}'.format(USER_MGT_URLS['PREFIX'], '/oauthIdpConfigs/oidc.provider')
+        _assert_request(recorder[0], 'DELETE',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs/oidc.provider')
 
     @pytest.mark.parametrize('arg', [None, 'foo', list(), dict(), 0, -1, 101, False])
     def test_invalid_max_results(self, user_mgt_app, arg):
@@ -302,9 +297,8 @@ def test_list_single_page(self, user_mgt_app):
         assert len(provider_configs) == 2
 
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}{1}'.format(USER_MGT_URLS['PREFIX'], '/oauthIdpConfigs?pageSize=100')
+        _assert_request(recorder[0], 'GET',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?pageSize=100')
 
     def test_list_multiple_pages(self, user_mgt_app):
         sample_response = json.loads(OIDC_PROVIDER_CONFIG_RESPONSE)
@@ -320,9 +314,8 @@ def test_list_multiple_pages(self, user_mgt_app):
 
         self._assert_page(page, next_page_token='token')
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/oauthIdpConfigs?pageSize=10'.format(USER_MGT_URLS['PREFIX'])
+        _assert_request(recorder[0], 'GET',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?pageSize=10')
 
         # Page 2 (also the last page)
         response = {'oauthIdpConfigs': configs[2:]}
@@ -331,10 +324,8 @@ def test_list_multiple_pages(self, user_mgt_app):
 
         self._assert_page(page, count=1, start=2)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/oauthIdpConfigs?pageSize=10&pageToken=token'.format(
-            USER_MGT_URLS['PREFIX'])
+        _assert_request(recorder[0], 'GET',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?pageSize=10&pageToken=token')
 
     def test_paged_iteration(self, user_mgt_app):
         sample_response = json.loads(OIDC_PROVIDER_CONFIG_RESPONSE)
@@ -353,9 +344,8 @@ def test_paged_iteration(self, user_mgt_app):
             provider_config = next(iterator)
             assert provider_config.provider_id == 'oidc.provider{0}'.format(index)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/oauthIdpConfigs?pageSize=100'.format(USER_MGT_URLS['PREFIX'])
+        _assert_request(recorder[0], 'GET',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?pageSize=100')
 
         # Page 2 (also the last page)
         response = {'oauthIdpConfigs': configs[2:]}
@@ -364,10 +354,8 @@ def test_paged_iteration(self, user_mgt_app):
         provider_config = next(iterator)
         assert provider_config.provider_id == 'oidc.provider2'
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/oauthIdpConfigs?pageSize=100&pageToken=token'.format(
-            USER_MGT_URLS['PREFIX'])
+        _assert_request(recorder[0], 'GET',
+                        f'{USER_MGT_URLS["PREFIX"]}/oauthIdpConfigs?pageSize=100&pageToken=token')
 
         with pytest.raises(StopIteration):
             next(iterator)
@@ -464,10 +452,8 @@ def test_get(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}{1}'.format(USER_MGT_URLS['PREFIX'],
-                                          '/inboundSamlConfigs/saml.provider')
+        _assert_request(recorder[0], 'GET',
+                        f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs/saml.provider')
 
     @pytest.mark.parametrize('invalid_opts', [
         {'provider_id': None}, {'provider_id': ''}, {'provider_id': 'oidc.provider'},
@@ -494,11 +480,10 @@ def test_create(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'POST'
-        assert req.url == '{0}/inboundSamlConfigs?inboundSamlConfigId=saml.provider'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'POST',
+                        f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?'
+                        f'inboundSamlConfigId=saml.provider')
+        got = json.loads(recorder[0].body.decode())
         assert got == self.SAML_CONFIG_REQUEST
 
     def test_create_minimal(self, user_mgt_app):
@@ -514,11 +499,10 @@ def test_create_minimal(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'POST'
-        assert req.url == '{0}/inboundSamlConfigs?inboundSamlConfigId=saml.provider'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'POST',
+                        f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?'
+                        f'inboundSamlConfigId=saml.provider')
+        got = json.loads(recorder[0].body.decode())
         assert got == want
 
     def test_create_empty_values(self, user_mgt_app):
@@ -534,11 +518,10 @@ def test_create_empty_values(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'POST'
-        assert req.url == '{0}/inboundSamlConfigs?inboundSamlConfigId=saml.provider'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'POST',
+                        f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?'
+                        f'inboundSamlConfigId=saml.provider')
+        got = json.loads(recorder[0].body.decode())
         assert got == want
 
     @pytest.mark.parametrize('invalid_opts', [
@@ -567,15 +550,14 @@ def test_update(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'PATCH'
         mask = [
             'displayName', 'enabled', 'idpConfig.idpCertificates', 'idpConfig.idpEntityId',
             'idpConfig.ssoUrl', 'spConfig.callbackUri', 'spConfig.spEntityId',
         ]
-        assert req.url == '{0}/inboundSamlConfigs/saml.provider?updateMask={1}'.format(
-            USER_MGT_URLS['PREFIX'], ','.join(mask))
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'PATCH',
+                        f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs/saml.provider?'
+                        f'updateMask={",".join(mask)}')
+        got = json.loads(recorder[0].body.decode())
         assert got == self.SAML_CONFIG_REQUEST
 
     def test_update_minimal(self, user_mgt_app):
@@ -586,11 +568,10 @@ def test_update_minimal(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'PATCH'
-        assert req.url == '{0}/inboundSamlConfigs/saml.provider?updateMask=displayName'.format(
-            USER_MGT_URLS['PREFIX'])
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'PATCH',
+                        f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs/saml.provider?'
+                        f'updateMask=displayName')
+        got = json.loads(recorder[0].body.decode())
         assert got == {'displayName': 'samlProviderName'}
 
     def test_update_empty_values(self, user_mgt_app):
@@ -601,12 +582,11 @@ def test_update_empty_values(self, user_mgt_app):
 
         self._assert_provider_config(provider_config)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'PATCH'
         mask = ['displayName', 'enabled']
-        assert req.url == '{0}/inboundSamlConfigs/saml.provider?updateMask={1}'.format(
-            USER_MGT_URLS['PREFIX'], ','.join(mask))
-        got = json.loads(req.body.decode())
+        _assert_request(recorder[0], 'PATCH',
+                        f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs/saml.provider?'
+                        f'updateMask={",".join(mask)}')
+        got = json.loads(recorder[0].body.decode())
         assert got == {'displayName': None, 'enabled': False}
 
     @pytest.mark.parametrize('provider_id', INVALID_PROVIDER_IDS + ['oidc.provider'])
@@ -622,10 +602,8 @@ def test_delete(self, user_mgt_app):
         auth.delete_saml_provider_config('saml.provider', app=user_mgt_app)
 
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'DELETE'
-        assert req.url == '{0}{1}'.format(USER_MGT_URLS['PREFIX'],
-                                          '/inboundSamlConfigs/saml.provider')
+        _assert_request(
+            recorder[0], 'DELETE', f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs/saml.provider')
 
     def test_config_not_found(self, user_mgt_app):
         _instrument_provider_mgt(user_mgt_app, 500, CONFIG_NOT_FOUND_RESPONSE)
@@ -658,10 +636,8 @@ def test_list_single_page(self, user_mgt_app):
         assert len(provider_configs) == 2
 
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}{1}'.format(USER_MGT_URLS['PREFIX'],
-                                          '/inboundSamlConfigs?pageSize=100')
+        _assert_request(
+            recorder[0], 'GET', f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?pageSize=100')
 
     def test_list_multiple_pages(self, user_mgt_app):
         sample_response = json.loads(SAML_PROVIDER_CONFIG_RESPONSE)
@@ -677,9 +653,8 @@ def test_list_multiple_pages(self, user_mgt_app):
 
         self._assert_page(page, next_page_token='token')
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/inboundSamlConfigs?pageSize=10'.format(USER_MGT_URLS['PREFIX'])
+        _assert_request(
+            recorder[0], 'GET', f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?pageSize=10')
 
         # Page 2 (also the last page)
         response = {'inboundSamlConfigs': configs[2:]}
@@ -688,10 +663,9 @@ def test_list_multiple_pages(self, user_mgt_app):
 
         self._assert_page(page, count=1, start=2)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/inboundSamlConfigs?pageSize=10&pageToken=token'.format(
-            USER_MGT_URLS['PREFIX'])
+        _assert_request(
+            recorder[0], 'GET',
+            f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?pageSize=10&pageToken=token')
 
     def test_paged_iteration(self, user_mgt_app):
         sample_response = json.loads(SAML_PROVIDER_CONFIG_RESPONSE)
@@ -710,9 +684,8 @@ def test_paged_iteration(self, user_mgt_app):
             provider_config = next(iterator)
             assert provider_config.provider_id == 'saml.provider{0}'.format(index)
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/inboundSamlConfigs?pageSize=100'.format(USER_MGT_URLS['PREFIX'])
+        _assert_request(
+            recorder[0], 'GET', f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?pageSize=100')
 
         # Page 2 (also the last page)
         response = {'inboundSamlConfigs': configs[2:]}
@@ -721,10 +694,9 @@ def test_paged_iteration(self, user_mgt_app):
         provider_config = next(iterator)
         assert provider_config.provider_id == 'saml.provider2'
         assert len(recorder) == 1
-        req = recorder[0]
-        assert req.method == 'GET'
-        assert req.url == '{0}/inboundSamlConfigs?pageSize=100&pageToken=token'.format(
-            USER_MGT_URLS['PREFIX'])
+        _assert_request(
+            recorder[0], 'GET',
+            f'{USER_MGT_URLS["PREFIX"]}/inboundSamlConfigs?pageSize=100&pageToken=token')
 
         with pytest.raises(StopIteration):
             next(iterator)
diff --git a/tests/test_db.py b/tests/test_db.py
index aa2c83bd9..4245f65fb 100644
--- a/tests/test_db.py
+++ b/tests/test_db.py
@@ -193,16 +193,20 @@ def instrument(self, ref, payload, status=200, etag=MockAdapter.ETAG):
         ref._client.session.mount(self.test_url, adapter)
         return recorder
 
+    def _assert_request(self, request, expected_method, expected_url):
+        assert request.method == expected_method
+        assert request.url == expected_url
+        assert request.headers['Authorization'] == 'Bearer mock-token'
+        assert request.headers['User-Agent'] == db._USER_AGENT
+        assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
+
     @pytest.mark.parametrize('data', valid_values)
     def test_get_value(self, data):
         ref = db.reference('/test')
         recorder = self.instrument(ref, json.dumps(data))
         assert ref.get() == data
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
+        self._assert_request(recorder[0], 'GET', 'https://test.firebaseio.com/test.json')
         assert 'X-Firebase-ETag' not in recorder[0].headers
 
     @pytest.mark.parametrize('data', valid_values)
@@ -211,10 +215,7 @@ def test_get_with_etag(self, data):
         recorder = self.instrument(ref, json.dumps(data))
         assert ref.get(etag=True) == (data, MockAdapter.ETAG)
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
+        self._assert_request(recorder[0], 'GET', 'https://test.firebaseio.com/test.json')
         assert recorder[0].headers['X-Firebase-ETag'] == 'true'
 
     @pytest.mark.parametrize('data', valid_values)
@@ -223,10 +224,8 @@ def test_get_shallow(self, data):
         recorder = self.instrument(ref, json.dumps(data))
         assert ref.get(shallow=True) == data
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?shallow=true'
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
+        self._assert_request(
+            recorder[0], 'GET', 'https://test.firebaseio.com/test.json?shallow=true')
 
     def test_get_with_etag_and_shallow(self):
         ref = db.reference('/test')
@@ -240,14 +239,12 @@ def test_get_if_changed(self, data):
 
         assert ref.get_if_changed('invalid-etag') == (True, data, MockAdapter.ETAG)
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
+        self._assert_request(recorder[0], 'GET', 'https://test.firebaseio.com/test.json')
         assert recorder[0].headers['if-none-match'] == 'invalid-etag'
 
         assert ref.get_if_changed(MockAdapter.ETAG) == (False, None, None)
         assert len(recorder) == 2
-        assert recorder[1].method == 'GET'
-        assert recorder[1].url == 'https://test.firebaseio.com/test.json'
+        self._assert_request(recorder[1], 'GET', 'https://test.firebaseio.com/test.json')
         assert recorder[1].headers['if-none-match'] == MockAdapter.ETAG
 
     @pytest.mark.parametrize('etag', [0, 1, True, False, dict(), list(), tuple()])
@@ -264,9 +261,8 @@ def test_order_by_query(self, data):
         query_str = 'orderBy=%22foo%22'
         assert query.get() == data
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?' + query_str
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
+        self._assert_request(
+            recorder[0], 'GET', 'https://test.firebaseio.com/test.json?' + query_str)
 
     @pytest.mark.parametrize('data', valid_values)
     def test_limit_query(self, data):
@@ -277,9 +273,8 @@ def test_limit_query(self, data):
         query_str = 'limitToFirst=100&orderBy=%22foo%22'
         assert query.get() == data
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?' + query_str
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
+        self._assert_request(
+            recorder[0], 'GET', 'https://test.firebaseio.com/test.json?' + query_str)
 
     @pytest.mark.parametrize('data', valid_values)
     def test_range_query(self, data):
@@ -291,9 +286,8 @@ def test_range_query(self, data):
         query_str = 'endAt=200&orderBy=%22foo%22&startAt=100'
         assert query.get() == data
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?' + query_str
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
+        self._assert_request(
+            recorder[0], 'GET', 'https://test.firebaseio.com/test.json?' + query_str)
 
     @pytest.mark.parametrize('data', valid_values)
     def test_set_value(self, data):
@@ -301,10 +295,9 @@ def test_set_value(self, data):
         recorder = self.instrument(ref, '')
         ref.set(data)
         assert len(recorder) == 1
-        assert recorder[0].method == 'PUT'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?print=silent'
+        self._assert_request(
+            recorder[0], 'PUT', 'https://test.firebaseio.com/test.json?print=silent')
         assert json.loads(recorder[0].body.decode()) == data
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
 
     def test_set_none_value(self):
         ref = db.reference('/test')
@@ -327,10 +320,9 @@ def test_update_children(self, data):
         recorder = self.instrument(ref, json.dumps(data))
         ref.update(data)
         assert len(recorder) == 1
-        assert recorder[0].method == 'PATCH'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?print=silent'
+        self._assert_request(
+            recorder[0], 'PATCH', 'https://test.firebaseio.com/test.json?print=silent')
         assert json.loads(recorder[0].body.decode()) == data
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
 
     @pytest.mark.parametrize('data', valid_values)
     def test_set_if_unchanged_success(self, data):
@@ -339,10 +331,8 @@ def test_set_if_unchanged_success(self, data):
         vals = ref.set_if_unchanged(MockAdapter.ETAG, data)
         assert vals == (True, data, MockAdapter.ETAG)
         assert len(recorder) == 1
-        assert recorder[0].method == 'PUT'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
+        self._assert_request(recorder[0], 'PUT', 'https://test.firebaseio.com/test.json')
         assert json.loads(recorder[0].body.decode()) == data
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
         assert recorder[0].headers['if-match'] == MockAdapter.ETAG
 
     @pytest.mark.parametrize('data', valid_values)
@@ -352,10 +342,8 @@ def test_set_if_unchanged_failure(self, data):
         vals = ref.set_if_unchanged('invalid-etag', data)
         assert vals == (False, {'foo':'bar'}, MockAdapter.ETAG)
         assert len(recorder) == 1
-        assert recorder[0].method == 'PUT'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
+        self._assert_request(recorder[0], 'PUT', 'https://test.firebaseio.com/test.json')
         assert json.loads(recorder[0].body.decode()) == data
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
         assert recorder[0].headers['if-match'] == 'invalid-etag'
 
     @pytest.mark.parametrize('etag', [0, 1, True, False, dict(), list(), tuple()])
@@ -397,22 +385,16 @@ def test_push(self, data):
         assert isinstance(child, db.Reference)
         assert child.key == 'testkey'
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
+        self._assert_request(recorder[0], 'POST', 'https://test.firebaseio.com/test.json')
         assert json.loads(recorder[0].body.decode()) == data
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
 
     def test_push_default(self):
         ref = db.reference('/test')
         recorder = self.instrument(ref, json.dumps({'name' : 'testkey'}))
         assert ref.push().key == 'testkey'
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
+        self._assert_request(recorder[0], 'POST', 'https://test.firebaseio.com/test.json')
         assert json.loads(recorder[0].body.decode()) == ''
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
 
     def test_push_none_value(self):
         ref = db.reference('/test')
@@ -425,10 +407,7 @@ def test_delete(self):
         recorder = self.instrument(ref, '')
         ref.delete()
         assert len(recorder) == 1
-        assert recorder[0].method == 'DELETE'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json'
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
+        self._assert_request(recorder[0], 'DELETE', 'https://test.firebaseio.com/test.json')
 
     def test_transaction(self):
         ref = db.reference('/test')
@@ -442,8 +421,8 @@ def transaction_update(data):
         new_value = ref.transaction(transaction_update)
         assert new_value == {'foo1' : 'bar1', 'foo2' : 'bar2'}
         assert len(recorder) == 2
-        assert recorder[0].method == 'GET'
-        assert recorder[1].method == 'PUT'
+        self._assert_request(recorder[0], 'GET', 'https://test.firebaseio.com/test.json')
+        self._assert_request(recorder[1], 'PUT', 'https://test.firebaseio.com/test.json')
         assert json.loads(recorder[1].body.decode()) == {'foo1': 'bar1', 'foo2': 'bar2'}
 
     def test_transaction_scalar(self):
@@ -454,8 +433,8 @@ def test_transaction_scalar(self):
         new_value = ref.transaction(lambda x: x + 1 if x else 1)
         assert new_value == 43
         assert len(recorder) == 2
-        assert recorder[0].method == 'GET'
-        assert recorder[1].method == 'PUT'
+        self._assert_request(recorder[0], 'GET', 'https://test.firebaseio.com/test/count.json')
+        self._assert_request(recorder[1], 'PUT', 'https://test.firebaseio.com/test/count.json')
         assert json.loads(recorder[1].body.decode()) == 43
 
     def test_transaction_error(self):
@@ -471,7 +450,7 @@ def transaction_update(data):
             ref.transaction(transaction_update)
         assert str(excinfo.value) == 'test error'
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
+        self._assert_request(recorder[0], 'GET', 'https://test.firebaseio.com/test.json')
 
     def test_transaction_abort(self):
         ref = db.reference('/test/count')
@@ -638,16 +617,21 @@ def instrument(self, ref, payload, status=200):
         ref._client.session.mount(self.test_url, adapter)
         return recorder
 
+    def _assert_request(self, request, expected_method, expected_url):
+        assert request.method == expected_method
+        assert request.url == expected_url
+        assert request.headers['Authorization'] == 'Bearer mock-token'
+        assert request.headers['User-Agent'] == db._USER_AGENT
+        assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
+
     def test_get_value(self):
         ref = db.reference('/test')
         recorder = self.instrument(ref, json.dumps('data'))
         query_str = 'auth_variable_override={0}'.format(self.encoded_override)
         assert ref.get() == 'data'
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?' + query_str
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
+        self._assert_request(
+            recorder[0], 'GET', 'https://test.firebaseio.com/test.json?' + query_str)
 
     def test_set_value(self):
         ref = db.reference('/test')
@@ -656,11 +640,9 @@ def test_set_value(self):
         ref.set(data)
         query_str = 'print=silent&auth_variable_override={0}'.format(self.encoded_override)
         assert len(recorder) == 1
-        assert recorder[0].method == 'PUT'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?' + query_str
+        self._assert_request(
+            recorder[0], 'PUT', 'https://test.firebaseio.com/test.json?' + query_str)
         assert json.loads(recorder[0].body.decode()) == data
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
 
     def test_order_by_query(self):
         ref = db.reference('/test')
@@ -669,10 +651,8 @@ def test_order_by_query(self):
         query_str = 'orderBy=%22foo%22&auth_variable_override={0}'.format(self.encoded_override)
         assert query.get() == 'data'
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?' + query_str
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
+        self._assert_request(
+            recorder[0], 'GET', 'https://test.firebaseio.com/test.json?' + query_str)
 
     def test_range_query(self):
         ref = db.reference('/test')
@@ -682,10 +662,8 @@ def test_range_query(self):
                      'auth_variable_override={0}'.format(self.encoded_override))
         assert query.get() == 'data'
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == 'https://test.firebaseio.com/test.json?' + query_str
-        assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
-        assert recorder[0].headers['User-Agent'] == db._USER_AGENT
+        self._assert_request(
+            recorder[0], 'GET', 'https://test.firebaseio.com/test.json?' + query_str)
 
 
 class TestDatabaseInitialization:
diff --git a/tests/test_functions.py b/tests/test_functions.py
index 75809c1ad..f8f675890 100644
--- a/tests/test_functions.py
+++ b/tests/test_functions.py
@@ -21,6 +21,7 @@
 
 import firebase_admin
 from firebase_admin import functions
+from firebase_admin import _utils
 from tests import testutils
 
 
@@ -121,6 +122,7 @@ def test_task_enqueue(self):
         assert recorder[0].url == _DEFAULT_REQUEST_URL
         assert recorder[0].headers['Content-Type'] == 'application/json'
         assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
+        assert recorder[0].headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
         assert task_id == 'test-task-id'
 
     def test_task_enqueue_with_extension(self):
@@ -137,6 +139,7 @@ def test_task_enqueue_with_extension(self):
         assert recorder[0].url == _CLOUD_TASKS_URL + resource_name
         assert recorder[0].headers['Content-Type'] == 'application/json'
         assert recorder[0].headers['Authorization'] == 'Bearer mock-token'
+        assert recorder[0].headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
         assert task_id == 'test-task-id'
 
     def test_task_delete(self):
@@ -146,6 +149,7 @@ def test_task_delete(self):
         assert len(recorder) == 1
         assert recorder[0].method == 'DELETE'
         assert recorder[0].url == _DEFAULT_TASK_URL
+        assert recorder[0].headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
 
 
 class TestTaskQueueOptions:
diff --git a/tests/test_http_client.py b/tests/test_http_client.py
index 12ba03b48..cc948b393 100644
--- a/tests/test_http_client.py
+++ b/tests/test_http_client.py
@@ -17,7 +17,7 @@
 from pytest_localserver import http
 import requests
 
-from firebase_admin import _http_client
+from firebase_admin import _http_client, _utils
 from tests import testutils
 
 
@@ -61,6 +61,18 @@ def test_base_url():
     assert recorder[0].method == 'GET'
     assert recorder[0].url == _TEST_URL + 'foo'
 
+def test_metrics_headers():
+    client = _http_client.HttpClient()
+    assert client.session is not None
+    recorder = _instrument(client, 'body')
+    resp = client.request('get', _TEST_URL)
+    assert resp.status_code == 200
+    assert resp.text == 'body'
+    assert len(recorder) == 1
+    assert recorder[0].method == 'GET'
+    assert recorder[0].url == _TEST_URL
+    assert recorder[0].headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
+
 def test_credential():
     client = _http_client.HttpClient(
         credential=testutils.MockGoogleCredential())
diff --git a/tests/test_instance_id.py b/tests/test_instance_id.py
index 08b0fe6db..720171cd9 100644
--- a/tests/test_instance_id.py
+++ b/tests/test_instance_id.py
@@ -20,6 +20,7 @@
 from firebase_admin import exceptions
 from firebase_admin import instance_id
 from firebase_admin import _http_client
+from firebase_admin import _utils
 from tests import testutils
 
 
@@ -64,6 +65,11 @@ def _instrument_iid_service(self, app, status=200, payload='True'):
             testutils.MockAdapter(payload, status, recorder))
         return iid_service, recorder
 
+    def _assert_request(self, request, expected_method, expected_url):
+        assert request.method == expected_method
+        assert request.url == expected_url
+        assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
+
     def _get_url(self, project_id, iid):
         return instance_id._IID_SERVICE_URL + 'project/{0}/instanceId/{1}'.format(project_id, iid)
 
@@ -86,8 +92,8 @@ def test_delete_instance_id(self):
         _, recorder = self._instrument_iid_service(app)
         instance_id.delete_instance_id('test_iid')
         assert len(recorder) == 1
-        assert recorder[0].method == 'DELETE'
-        assert recorder[0].url == self._get_url('explicit-project-id', 'test_iid')
+        self._assert_request(
+            recorder[0], 'DELETE', self._get_url('explicit-project-id', 'test_iid'))
 
     def test_delete_instance_id_with_explicit_app(self):
         cred = testutils.MockCredential()
@@ -95,8 +101,8 @@ def test_delete_instance_id_with_explicit_app(self):
         _, recorder = self._instrument_iid_service(app)
         instance_id.delete_instance_id('test_iid', app)
         assert len(recorder) == 1
-        assert recorder[0].method == 'DELETE'
-        assert recorder[0].url == self._get_url('explicit-project-id', 'test_iid')
+        self._assert_request(
+            recorder[0], 'DELETE', self._get_url('explicit-project-id', 'test_iid'))
 
     @pytest.mark.parametrize('status', http_errors.keys())
     def test_delete_instance_id_error(self, status):
@@ -114,8 +120,8 @@ def test_delete_instance_id_error(self, status):
         else:
             # 401 responses are automatically retried by google-auth
             assert len(recorder) == 3
-        assert recorder[0].method == 'DELETE'
-        assert recorder[0].url == self._get_url('explicit-project-id', 'test_iid')
+        self._assert_request(
+            recorder[0], 'DELETE', self._get_url('explicit-project-id', 'test_iid'))
 
     def test_delete_instance_id_unexpected_error(self):
         cred = testutils.MockCredential()
@@ -129,8 +135,7 @@ def test_delete_instance_id_unexpected_error(self):
         assert excinfo.value.cause is not None
         assert excinfo.value.http_response is not None
         assert len(recorder) == 1
-        assert recorder[0].method == 'DELETE'
-        assert recorder[0].url == url
+        self._assert_request(recorder[0], 'DELETE', url)
 
     @pytest.mark.parametrize('iid', [None, '', 0, 1, True, False, list(), dict(), tuple()])
     def test_invalid_instance_id(self, iid):
diff --git a/tests/test_messaging.py b/tests/test_messaging.py
index d482438f5..edb36f53a 100644
--- a/tests/test_messaging.py
+++ b/tests/test_messaging.py
@@ -25,6 +25,7 @@
 from firebase_admin import exceptions
 from firebase_admin import messaging
 from firebase_admin import _http_client
+from firebase_admin import _utils
 from tests import testutils
 
 
@@ -1660,6 +1661,18 @@ def _instrument_messaging_service(self, app=None, status=200, payload=_DEFAULT_R
             testutils.MockAdapter(payload, status, recorder))
         return fcm_service, recorder
 
+
+    def _assert_request(self, request, expected_method, expected_url, expected_body=None):
+        assert request.method == expected_method
+        assert request.url == expected_url
+        assert request.headers['X-GOOG-API-FORMAT-VERSION'] == '2'
+        assert request.headers['X-FIREBASE-CLIENT'] == self._CLIENT_VERSION
+        assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
+        if expected_body is None:
+            assert request.body is None
+        else:
+            assert json.loads(request.body.decode()) == expected_body
+
     def _get_url(self, project_id):
         return messaging._MessagingService.FCM_URL.format(project_id)
 
@@ -1682,15 +1695,11 @@ def test_send_dry_run(self):
         msg_id = messaging.send(msg, dry_run=True)
         assert msg_id == 'message-id'
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('explicit-project-id')
-        assert recorder[0].headers['X-GOOG-API-FORMAT-VERSION'] == '2'
-        assert recorder[0].headers['X-FIREBASE-CLIENT'] == self._CLIENT_VERSION
         body = {
             'message': messaging._MessagingService.encode_message(msg),
             'validate_only': True,
         }
-        assert json.loads(recorder[0].body.decode()) == body
+        self._assert_request(recorder[0], 'POST', self._get_url('explicit-project-id'), body)
 
     def test_send(self):
         _, recorder = self._instrument_messaging_service()
@@ -1698,12 +1707,8 @@ def test_send(self):
         msg_id = messaging.send(msg)
         assert msg_id == 'message-id'
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('explicit-project-id')
-        assert recorder[0].headers['X-GOOG-API-FORMAT-VERSION'] == '2'
-        assert recorder[0].headers['X-FIREBASE-CLIENT'] == self._CLIENT_VERSION
         body = {'message': messaging._MessagingService.encode_message(msg)}
-        assert json.loads(recorder[0].body.decode()) == body
+        self._assert_request(recorder[0], 'POST', self._get_url('explicit-project-id'), body)
 
     @pytest.mark.parametrize('status,exc_type', HTTP_ERROR_CODES.items())
     def test_send_error(self, status, exc_type):
@@ -1714,12 +1719,8 @@ def test_send_error(self, status, exc_type):
         expected = 'Unexpected HTTP response with status: {0}; body: {{}}'.format(status)
         check_exception(excinfo.value, expected, status)
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('explicit-project-id')
-        assert recorder[0].headers['X-GOOG-API-FORMAT-VERSION'] == '2'
-        assert recorder[0].headers['X-FIREBASE-CLIENT'] == self._CLIENT_VERSION
         body = {'message': messaging._MessagingService.JSON_ENCODER.default(msg)}
-        assert json.loads(recorder[0].body.decode()) == body
+        self._assert_request(recorder[0], 'POST', self._get_url('explicit-project-id'), body)
 
     @pytest.mark.parametrize('status', HTTP_ERROR_CODES)
     def test_send_detailed_error(self, status):
@@ -1735,10 +1736,8 @@ def test_send_detailed_error(self, status):
             messaging.send(msg)
         check_exception(excinfo.value, 'test error', status)
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('explicit-project-id')
         body = {'message': messaging._MessagingService.JSON_ENCODER.default(msg)}
-        assert json.loads(recorder[0].body.decode()) == body
+        self._assert_request(recorder[0], 'POST', self._get_url('explicit-project-id'), body)
 
     @pytest.mark.parametrize('status', HTTP_ERROR_CODES)
     def test_send_canonical_error_code(self, status):
@@ -1754,10 +1753,8 @@ def test_send_canonical_error_code(self, status):
             messaging.send(msg)
         check_exception(excinfo.value, 'test error', status)
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('explicit-project-id')
         body = {'message': messaging._MessagingService.JSON_ENCODER.default(msg)}
-        assert json.loads(recorder[0].body.decode()) == body
+        self._assert_request(recorder[0], 'POST', self._get_url('explicit-project-id'), body)
 
     @pytest.mark.parametrize('status', HTTP_ERROR_CODES)
     @pytest.mark.parametrize('fcm_error_code, exc_type', FCM_ERROR_CODES.items())
@@ -1780,10 +1777,8 @@ def test_send_fcm_error_code(self, status, fcm_error_code, exc_type):
             messaging.send(msg)
         check_exception(excinfo.value, 'test error', status)
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('explicit-project-id')
         body = {'message': messaging._MessagingService.JSON_ENCODER.default(msg)}
-        assert json.loads(recorder[0].body.decode()) == body
+        self._assert_request(recorder[0], 'POST', self._get_url('explicit-project-id'), body)
 
     @pytest.mark.parametrize('status', HTTP_ERROR_CODES)
     def test_send_unknown_fcm_error_code(self, status):
@@ -1805,10 +1800,8 @@ def test_send_unknown_fcm_error_code(self, status):
             messaging.send(msg)
         check_exception(excinfo.value, 'test error', status)
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('explicit-project-id')
         body = {'message': messaging._MessagingService.JSON_ENCODER.default(msg)}
-        assert json.loads(recorder[0].body.decode()) == body
+        self._assert_request(recorder[0], 'POST', self._get_url('explicit-project-id'), body)
 
 
 class _HttpMockException:
@@ -2591,6 +2584,12 @@ def _instrument_iid_service(self, app=None, status=200, payload=_DEFAULT_RESPONS
             testutils.MockAdapter(payload, status, recorder))
         return fcm_service, recorder
 
+    def _assert_request(self, request, expected_method, expected_url):
+        assert request.method == expected_method
+        assert request.url == expected_url
+        assert request.headers['access_token_auth'] == 'true'
+        assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
+
     def _get_url(self, path):
         return '{0}/{1}'.format(messaging._MessagingService.IID_URL, path)
 
@@ -2625,8 +2624,7 @@ def test_subscribe_to_topic(self, args):
         resp = messaging.subscribe_to_topic(args[0], args[1])
         self._check_response(resp)
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('iid/v1:batchAdd')
+        self._assert_request(recorder[0], 'POST', self._get_url('iid/v1:batchAdd'))
         assert json.loads(recorder[0].body.decode()) == args[2]
 
     @pytest.mark.parametrize('status, exc_type', HTTP_ERROR_CODES.items())
@@ -2637,8 +2635,7 @@ def test_subscribe_to_topic_error(self, status, exc_type):
             messaging.subscribe_to_topic('foo', 'test-topic')
         assert str(excinfo.value) == 'Error while calling the IID service: error_reason'
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('iid/v1:batchAdd')
+        self._assert_request(recorder[0], 'POST', self._get_url('iid/v1:batchAdd'))
 
     @pytest.mark.parametrize('status, exc_type', HTTP_ERROR_CODES.items())
     def test_subscribe_to_topic_non_json_error(self, status, exc_type):
@@ -2648,8 +2645,7 @@ def test_subscribe_to_topic_non_json_error(self, status, exc_type):
         reason = 'Unexpected HTTP response with status: {0}; body: not json'.format(status)
         assert str(excinfo.value) == reason
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('iid/v1:batchAdd')
+        self._assert_request(recorder[0], 'POST', self._get_url('iid/v1:batchAdd'))
 
     @pytest.mark.parametrize('args', _VALID_ARGS)
     def test_unsubscribe_from_topic(self, args):
@@ -2657,8 +2653,7 @@ def test_unsubscribe_from_topic(self, args):
         resp = messaging.unsubscribe_from_topic(args[0], args[1])
         self._check_response(resp)
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('iid/v1:batchRemove')
+        self._assert_request(recorder[0], 'POST', self._get_url('iid/v1:batchRemove'))
         assert json.loads(recorder[0].body.decode()) == args[2]
 
     @pytest.mark.parametrize('status, exc_type', HTTP_ERROR_CODES.items())
@@ -2669,8 +2664,7 @@ def test_unsubscribe_from_topic_error(self, status, exc_type):
             messaging.unsubscribe_from_topic('foo', 'test-topic')
         assert str(excinfo.value) == 'Error while calling the IID service: error_reason'
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('iid/v1:batchRemove')
+        self._assert_request(recorder[0], 'POST', self._get_url('iid/v1:batchRemove'))
 
     @pytest.mark.parametrize('status, exc_type', HTTP_ERROR_CODES.items())
     def test_unsubscribe_from_topic_non_json_error(self, status, exc_type):
@@ -2680,8 +2674,7 @@ def test_unsubscribe_from_topic_non_json_error(self, status, exc_type):
         reason = 'Unexpected HTTP response with status: {0}; body: not json'.format(status)
         assert str(excinfo.value) == reason
         assert len(recorder) == 1
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == self._get_url('iid/v1:batchRemove')
+        self._assert_request(recorder[0], 'POST', self._get_url('iid/v1:batchRemove'))
 
     def _check_response(self, resp):
         assert resp.success_count == 1
diff --git a/tests/test_ml.py b/tests/test_ml.py
index abd6d06f9..137fe4cf6 100644
--- a/tests/test_ml.py
+++ b/tests/test_ml.py
@@ -21,12 +21,11 @@
 import firebase_admin
 from firebase_admin import exceptions
 from firebase_admin import ml
+from firebase_admin import _utils
 from tests import testutils
 
 
 BASE_URL = 'https://firebaseml.googleapis.com/v1beta2/'
-HEADER_CLIENT_KEY = 'X-FIREBASE-CLIENT'
-HEADER_CLIENT_VALUE = 'fire-admin-python/{0}'.format(firebase_admin.__version__)
 PROJECT_ID = 'my-project-1'
 
 PAGE_TOKEN = 'pageToken'
@@ -336,6 +335,12 @@ def instrument_ml_service(status=200, payload=None, operations=False, app=None):
             session_url, adapter(payload, status, recorder))
     return recorder
 
+def _assert_request(request, expected_method, expected_url):
+    assert request.method == expected_method
+    assert request.url == expected_url
+    assert request.headers['X-FIREBASE-CLIENT'] == f'fire-admin-python/{firebase_admin.__version__}'
+    assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
+
 class _TestStorageClient:
     @staticmethod
     def upload(bucket_name, model_file_name, app):
@@ -599,9 +604,7 @@ def test_wait_for_unlocked(self):
         model.wait_for_unlocked()
         assert model == FULL_MODEL_PUBLISHED
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == TestModel._op_url(PROJECT_ID)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'GET', TestModel._op_url(PROJECT_ID))
 
     def test_wait_for_unlocked_timeout(self):
         recorder = instrument_ml_service(
@@ -653,12 +656,8 @@ def test_returns_locked(self):
 
         assert model == expected_model
         assert len(recorder) == 2
-        assert recorder[0].method == 'POST'
-        assert recorder[0].url == TestCreateModel._url(PROJECT_ID)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
-        assert recorder[1].method == 'GET'
-        assert recorder[1].url == TestCreateModel._get_url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[1].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'POST', TestCreateModel._url(PROJECT_ID))
+        _assert_request(recorder[1], 'GET', TestCreateModel._get_url(PROJECT_ID, MODEL_ID_1))
 
     def test_operation_error(self):
         instrument_ml_service(status=200, payload=OPERATION_ERROR_RESPONSE)
@@ -747,12 +746,8 @@ def test_returns_locked(self):
 
         assert model == expected_model
         assert len(recorder) == 2
-        assert recorder[0].method == 'PATCH'
-        assert recorder[0].url == TestUpdateModel._url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
-        assert recorder[1].method == 'GET'
-        assert recorder[1].url == TestUpdateModel._url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[1].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'PATCH', TestUpdateModel._url(PROJECT_ID, MODEL_ID_1))
+        _assert_request(recorder[1], 'GET', TestUpdateModel._url(PROJECT_ID, MODEL_ID_1))
 
     def test_operation_error(self):
         instrument_ml_service(status=200, payload=OPERATION_ERROR_RESPONSE)
@@ -846,9 +841,8 @@ def test_immediate_done(self, publish_function, published):
         model = publish_function(MODEL_ID_1)
         assert model == CREATED_UPDATED_MODEL_1
         assert len(recorder) == 1
-        assert recorder[0].method == 'PATCH'
-        assert recorder[0].url == TestPublishUnpublish._update_url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(
+            recorder[0], 'PATCH', TestPublishUnpublish._update_url(PROJECT_ID, MODEL_ID_1))
         body = json.loads(recorder[0].body.decode())
         assert body.get('state', {}).get('published', None) is published
 
@@ -862,12 +856,10 @@ def test_returns_locked(self, publish_function):
 
         assert model == expected_model
         assert len(recorder) == 2
-        assert recorder[0].method == 'PATCH'
-        assert recorder[0].url == TestPublishUnpublish._update_url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
-        assert recorder[1].method == 'GET'
-        assert recorder[1].url == TestPublishUnpublish._get_url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[1].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(
+            recorder[0], 'PATCH', TestPublishUnpublish._update_url(PROJECT_ID, MODEL_ID_1))
+        _assert_request(
+            recorder[1], 'GET', TestPublishUnpublish._get_url(PROJECT_ID, MODEL_ID_1))
 
     @pytest.mark.parametrize('publish_function', PUBLISH_UNPUBLISH_FUNCS)
     def test_operation_error(self, publish_function):
@@ -918,9 +910,7 @@ def test_get_model(self):
         recorder = instrument_ml_service(status=200, payload=DEFAULT_GET_RESPONSE)
         model = ml.get_model(MODEL_ID_1)
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == TestGetModel._url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'GET', TestGetModel._url(PROJECT_ID, MODEL_ID_1))
         assert model == MODEL_1
         assert model.model_id == MODEL_ID_1
         assert model.display_name == DISPLAY_NAME_1
@@ -942,9 +932,7 @@ def test_get_model_error(self):
             ERROR_MSG_NOT_FOUND
         )
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == TestGetModel._url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'GET', TestGetModel._url(PROJECT_ID, MODEL_ID_1))
 
     def test_no_project_id(self):
         def evaluate():
@@ -973,9 +961,7 @@ def test_delete_model(self):
         recorder = instrument_ml_service(status=200, payload=EMPTY_RESPONSE)
         ml.delete_model(MODEL_ID_1) # no response for delete
         assert len(recorder) == 1
-        assert recorder[0].method == 'DELETE'
-        assert recorder[0].url == TestDeleteModel._url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'DELETE', TestDeleteModel._url(PROJECT_ID, MODEL_ID_1))
 
     @pytest.mark.parametrize('model_id, exc_type', INVALID_MODEL_ID_ARGS)
     def test_delete_model_validation_errors(self, model_id, exc_type):
@@ -994,9 +980,7 @@ def test_delete_model_error(self):
             ERROR_MSG_NOT_FOUND
         )
         assert len(recorder) == 1
-        assert recorder[0].method == 'DELETE'
-        assert recorder[0].url == self._url(PROJECT_ID, MODEL_ID_1)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'DELETE', self._url(PROJECT_ID, MODEL_ID_1))
 
     def test_no_project_id(self):
         def evaluate():
@@ -1032,9 +1016,7 @@ def test_list_models_no_args(self):
         recorder = instrument_ml_service(status=200, payload=DEFAULT_LIST_RESPONSE)
         models_page = ml.list_models()
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == TestListModels._url(PROJECT_ID)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'GET', TestListModels._url(PROJECT_ID))
         TestListModels._check_page(models_page, 2)
         assert models_page.has_next_page
         assert models_page.next_page_token == NEXT_PAGE_TOKEN
@@ -1048,12 +1030,10 @@ def test_list_models_with_all_args(self):
             page_size=10,
             page_token=PAGE_TOKEN)
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == (
+        _assert_request(recorder[0], 'GET', (
             TestListModels._url(PROJECT_ID) +
             '?filter=display_name%3DdisplayName3&page_size=10&page_token={0}'
-            .format(PAGE_TOKEN))
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+            .format(PAGE_TOKEN)))
         assert isinstance(models_page, ml.ListModelsPage)
         assert len(models_page.models) == 1
         assert models_page.models[0] == MODEL_3
@@ -1097,9 +1077,7 @@ def test_list_models_error(self):
             ERROR_MSG_BAD_REQUEST
         )
         assert len(recorder) == 1
-        assert recorder[0].method == 'GET'
-        assert recorder[0].url == TestListModels._url(PROJECT_ID)
-        assert recorder[0].headers[HEADER_CLIENT_KEY] == HEADER_CLIENT_VALUE
+        _assert_request(recorder[0], 'GET', TestListModels._url(PROJECT_ID))
 
     def test_no_project_id(self):
         def evaluate():
diff --git a/tests/test_project_management.py b/tests/test_project_management.py
index 183195510..0a1bf97e5 100644
--- a/tests/test_project_management.py
+++ b/tests/test_project_management.py
@@ -23,6 +23,7 @@
 from firebase_admin import exceptions
 from firebase_admin import project_management
 from firebase_admin import _http_client
+from firebase_admin import _utils
 from tests import testutils
 
 OPERATION_IN_PROGRESS_RESPONSE = json.dumps({
@@ -521,8 +522,8 @@ def _assert_request_is_correct(
             self, request, expected_method, expected_url, expected_body=None):
         assert request.method == expected_method
         assert request.url == expected_url
-        client_version = 'Python/Admin/{0}'.format(firebase_admin.__version__)
-        assert request.headers['X-Client-Version'] == client_version
+        assert request.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+        assert request.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
         if expected_body is None:
             assert request.body is None
         else:
diff --git a/tests/test_tenant_mgt.py b/tests/test_tenant_mgt.py
index 53b766239..1da6d938a 100644
--- a/tests/test_tenant_mgt.py
+++ b/tests/test_tenant_mgt.py
@@ -26,6 +26,7 @@
 from firebase_admin import tenant_mgt
 from firebase_admin import _auth_providers
 from firebase_admin import _user_mgt
+from firebase_admin import _utils
 from tests import testutils
 from tests import test_token_gen
 
@@ -195,6 +196,8 @@ def test_get_tenant(self, tenant_mgt_app):
         req = recorder[0]
         assert req.method == 'GET'
         assert req.url == '{0}/tenants/tenant-id'.format(TENANT_MGT_URL_PREFIX)
+        assert req.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+        assert req.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
 
     def test_tenant_not_found(self, tenant_mgt_app):
         _instrument_tenant_mgt(tenant_mgt_app, 500, TENANT_NOT_FOUND_RESPONSE)
@@ -285,6 +288,8 @@ def _assert_request(self, recorder, body):
         req = recorder[0]
         assert req.method == 'POST'
         assert req.url == '{0}/tenants'.format(TENANT_MGT_URL_PREFIX)
+        assert req.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+        assert req.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
         got = json.loads(req.body.decode())
         assert got == body
 
@@ -383,6 +388,8 @@ def _assert_request(self, recorder, body, mask):
         assert req.method == 'PATCH'
         assert req.url == '{0}/tenants/tenant-id?updateMask={1}'.format(
             TENANT_MGT_URL_PREFIX, ','.join(mask))
+        assert req.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+        assert req.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
         got = json.loads(req.body.decode())
         assert got == body
 
@@ -403,6 +410,8 @@ def test_delete_tenant(self, tenant_mgt_app):
         req = recorder[0]
         assert req.method == 'DELETE'
         assert req.url == '{0}/tenants/tenant-id'.format(TENANT_MGT_URL_PREFIX)
+        assert req.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+        assert req.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
 
     def test_tenant_not_found(self, tenant_mgt_app):
         _instrument_tenant_mgt(tenant_mgt_app, 500, TENANT_NOT_FOUND_RESPONSE)
@@ -545,6 +554,8 @@ def _assert_request(self, recorder, expected=None):
         assert len(recorder) == 1
         req = recorder[0]
         assert req.method == 'GET'
+        assert req.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+        assert req.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
         request = dict(parse.parse_qsl(parse.urlsplit(req.url).query))
         assert request == expected
 
@@ -920,6 +931,8 @@ def _assert_request(
         req = recorder[0]
         assert req.method == method
         assert req.url == '{0}/tenants/tenant-id{1}'.format(prefix, want_url)
+        assert req.headers['X-Client-Version'] == f'Python/Admin/{firebase_admin.__version__}'
+        assert req.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
         body = json.loads(req.body.decode())
         assert body == want_body
 
diff --git a/tests/test_user_mgt.py b/tests/test_user_mgt.py
index ea9c87e6f..604ec9959 100644
--- a/tests/test_user_mgt.py
+++ b/tests/test_user_mgt.py
@@ -28,6 +28,7 @@
 from firebase_admin import _http_client
 from firebase_admin import _user_import
 from firebase_admin import _user_mgt
+from firebase_admin import _utils
 from tests import testutils
 
 
@@ -135,6 +136,7 @@ def _check_request(recorder, want_url, want_body=None, want_timeout=None):
     req = recorder[0]
     assert req.method == 'POST'
     assert req.url == '{0}{1}'.format(USER_MGT_URLS['PREFIX'], want_url)
+    assert req.headers['X-GOOG-API-CLIENT'] == _utils.get_metrics_header()
     if want_body:
         body = json.loads(req.body.decode())
         assert body == want_body