fix: use lowercase x-goog-api-client header (#18064)

chandra-siri · web-flow · commit d465d1ebdb03 · 2026-08-11T10:29:14.000-04:00
Use lowercase 'x-goog-api-client' header key to ensure compatibility
with google-auth library's metric tracking.

BUG=b/477154133
TAG=agy
CONV=2f25336d-e8f9-413f-8292-73b7a55c1d81
diff --git a/packages/google-cloud-core/google/cloud/_http/__init__.py b/packages/google-cloud-core/google/cloud/_http/__init__.py
@@ -49,7 +49,7 @@
 DEFAULT_USER_AGENT = "gcloud-python/{0}".format(version.__version__)
 """The user agent for google-cloud-python requests."""
 
-CLIENT_INFO_HEADER = "X-Goog-API-Client"
+CLIENT_INFO_HEADER = "x-goog-api-client"
 CLIENT_INFO_TEMPLATE = "gl-python/" + platform.python_version() + " gccl/{}"
 
 _USER_AGENT_ALL_CAPS_DEPRECATED = """\
diff --git a/packages/google-cloud-storage/google/cloud/storage/_helpers.py b/packages/google-cloud-storage/google/cloud/storage/_helpers.py
@@ -767,7 +767,7 @@ def _get_default_headers(
         "Accept": "application/json",
         "Accept-Encoding": "gzip, deflate",
         "User-Agent": user_agent,
-        "X-Goog-API-Client": x_goog_api_client,
+        "x-goog-api-client": x_goog_api_client,
         "content-type": content_type,
         "x-upload-content-type": x_upload_content_type or content_type,
     }
diff --git a/packages/google-cloud-storage/tests/unit/test_blob.py b/packages/google-cloud-storage/tests/unit/test_blob.py
@@ -2688,7 +2688,7 @@ def test__get_upload_arguments(self):
                 **custom_headers,
             }
         self.assertEqual(
-            headers["X-Goog-API-Client"],
+            headers["x-goog-api-client"],
             f"{client._connection.user_agent} {GCCL_INVOCATION_TEST_CONST} gccl-gcs-cmd/{COMMAND}",
         )
         self.assertEqual(headers, expected_headers)
diff --git a/packages/google-cloud-storage/tests/unit/test_client.py b/packages/google-cloud-storage/tests/unit/test_client.py
@@ -2169,8 +2169,8 @@ def test_download_blob_have_different_uuid(self):
         client.download_blob_to_file(blob, file_obj)
 
         self.assertNotEqual(
-            blob._do_download.call_args_list[0][0][3]["X-Goog-API-Client"],
-            blob._do_download.call_args_list[1][0][3]["X-Goog-API-Client"],
+            blob._do_download.call_args_list[0][0][3]["x-goog-api-client"],
+            blob._do_download.call_args_list[1][0][3]["x-goog-api-client"],
         )
 
     def test_list_blobs_w_defaults_w_bucket_obj(self):
diff --git a/packages/google-cloud-storage/tests/unit/test_transfer_manager.py b/packages/google-cloud-storage/tests/unit/test_transfer_manager.py
@@ -1218,7 +1218,7 @@ def test_upload_chunks_concurrently_with_metadata_and_encryption():
             "Accept": "application/json",
             "Accept-Encoding": "gzip, deflate",
             "User-Agent": "agent",
-            "X-Goog-API-Client": f"agent gccl-invocation-id/{invocation_id} gccl-gcs-cmd/tm.upload_sharded",
+            "x-goog-api-client": f"agent gccl-invocation-id/{invocation_id} gccl-gcs-cmd/tm.upload_sharded",
             "content-type": FAKE_CONTENT_TYPE,
             "x-upload-content-type": FAKE_CONTENT_TYPE,
             "X-Goog-Encryption-Algorithm": "AES256",

Original file line number	Diff line number	Diff line change
`@@ -767,7 +767,7 @@ def _get_default_headers(`
`767`	`767`	`"Accept": "application/json",`
`768`	`768`	`"Accept-Encoding": "gzip, deflate",`
`769`	`769`	`"User-Agent": user_agent,`
`770`		`- "X-Goog-API-Client": x_goog_api_client,`
	`770`	`+ "x-goog-api-client": x_goog_api_client,`
`771`	`771`	`"content-type": content_type,`
`772`	`772`	`"x-upload-content-type": x_upload_content_type or content_type,`
`773`	`773`	`}`
Original file line number	Diff line number	Diff line change
`@@ -2688,7 +2688,7 @@ def test__get_upload_arguments(self):`
`2688`	`2688`	`**custom_headers,`
`2689`	`2689`	`}`
`2690`	`2690`	`self.assertEqual(`
`2691`		`- headers["X-Goog-API-Client"],`
	`2691`	`+ headers["x-goog-api-client"],`
`2692`	`2692`	`f"{client._connection.user_agent} {GCCL_INVOCATION_TEST_CONST} gccl-gcs-cmd/{COMMAND}",`
`2693`	`2693`	`)`
`2694`	`2694`	`self.assertEqual(headers, expected_headers)`
Original file line number	Diff line number	Diff line change
`@@ -2169,8 +2169,8 @@ def test_download_blob_have_different_uuid(self):`
`2169`	`2169`	`client.download_blob_to_file(blob, file_obj)`
`2170`	`2170`
`2171`	`2171`	`self.assertNotEqual(`
`2172`		`- blob._do_download.call_args_list[0][0][3]["X-Goog-API-Client"],`
`2173`		`- blob._do_download.call_args_list[1][0][3]["X-Goog-API-Client"],`
	`2172`	`+ blob._do_download.call_args_list[0][0][3]["x-goog-api-client"],`
	`2173`	`+ blob._do_download.call_args_list[1][0][3]["x-goog-api-client"],`
`2174`	`2174`	`)`
`2175`	`2175`
`2176`	`2176`	`def test_list_blobs_w_defaults_w_bucket_obj(self):`