From c1c1ab1f31a8b69a1308b5423d66684f5415b9a7 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:06:02 -0400
Subject: [PATCH 01/21] feat(api-core): update pyproject.toml to require Python
 3.10+

---
 packages/google-api-core/pyproject.toml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/google-api-core/pyproject.toml b/packages/google-api-core/pyproject.toml
index c81667215d45..698454cbeac3 100644
--- a/packages/google-api-core/pyproject.toml
+++ b/packages/google-api-core/pyproject.toml
@@ -20,7 +20,7 @@ build-backend = "setuptools.build_meta"
 name = "google-api-core"
 authors = [{ name = "Google LLC", email = "googleapis-packages@google.com" }]
 license = { text = "Apache 2.0" }
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 readme = "README.rst"
 description = "Google API client core library"
 classifiers = [
@@ -34,7 +34,6 @@ classifiers = [
   "Programming Language :: Python",
   "Programming Language :: Python :: 3",
 
-  "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",

From d7b5ddc523220924d5d1f051ba14622854fe2982 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:11:34 -0400
Subject: [PATCH 02/21] docs(api-core): update README for Python 3.10+ support

---
 packages/google-api-core/README.rst | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/google-api-core/README.rst b/packages/google-api-core/README.rst
index 680556768fee..6e477cd224c4 100644
--- a/packages/google-api-core/README.rst
+++ b/packages/google-api-core/README.rst
@@ -16,13 +16,13 @@ common helpers used by all Google API clients. For more information, see the
 
 Supported Python Versions
 -------------------------
-Python >= 3.9
+Python >= 3.10
 
 
 Unsupported Python Versions
 ---------------------------
 
-Python == 2.7, Python == 3.5, Python == 3.6, Python == 3.7, Python == 3.8.
+Python == 2.7, Python == 3.5, Python == 3.6, Python == 3.7, Python == 3.8, Python == 3.9.
 
 The last version of this library compatible with Python 2.7 and 3.5 is
 `google-api-core==1.31.1`.
@@ -32,3 +32,6 @@ The last version of this library compatible with Python 3.6 is
 
 The last version of this library compatible with Python 3.7 and 3.8 is
 `google-api-core==2.29.0`.
+
+The last version of this library compatible with Python 3.9 is
+`google-api-core==2.30.3`.

From 0c736a6a8c36090664701b28458fbb484087e1e6 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:11:48 -0400
Subject: [PATCH 03/21] test(api-core): remove Python < 3.10 polyfills and
 skips

---
 .../google-api-core/tests/asyncio/test_bidi_async.py | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/packages/google-api-core/tests/asyncio/test_bidi_async.py b/packages/google-api-core/tests/asyncio/test_bidi_async.py
index add685a96c2c..10e2ce44444b 100644
--- a/packages/google-api-core/tests/asyncio/test_bidi_async.py
+++ b/packages/google-api-core/tests/asyncio/test_bidi_async.py
@@ -33,14 +33,6 @@
 from google.api_core import bidi_async
 from google.api_core import exceptions
 
-# TODO: remove this when droppping support for "Python 3.10" and below.
-if sys.version_info < (3, 10):  # type: ignore[operator]
-
-    def aiter(obj):
-        return obj.__aiter__()
-
-    async def anext(obj):
-        return await obj.__anext__()
 
 
 @pytest.mark.asyncio
@@ -185,10 +177,6 @@ def test_done_callbacks(self):
         callback.assert_called_once_with(mock.sentinel.future)
 
     @pytest.mark.asyncio
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),  # type: ignore[operator]
-        reason="Versions of Python below 3.8 don't provide support for assert_awaited_once",
-    )
     async def test_metadata(self):
         rpc, call = make_async_rpc()
         bidi_rpc = bidi_async.AsyncBidiRpc(rpc, metadata=mock.sentinel.A)

From 821322bd0b8b7e55cc7f50ca34eaa7611877d099 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:11:55 -0400
Subject: [PATCH 04/21] docs(api-core): update docstring in
 grpc_helpers_async.py for Python 3.10+

---
 packages/google-api-core/google/api_core/grpc_helpers_async.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/google-api-core/google/api_core/grpc_helpers_async.py b/packages/google-api-core/google/api_core/grpc_helpers_async.py
index 9e1ad1105d45..b615d8a13252 100644
--- a/packages/google-api-core/google/api_core/grpc_helpers_async.py
+++ b/packages/google-api-core/google/api_core/grpc_helpers_async.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""AsyncIO helpers for :mod:`grpc` supporting 3.7+.
+"""AsyncIO helpers for :mod:`grpc` supporting 3.10+.
 
 Please combine more detailed docstring in grpc_helpers.py to use following
 functions. This module is implementing the same surface with AsyncIO semantics.

From 87e885e0003f48d4b2d44b368815911a60abaa16 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:12:04 -0400
Subject: [PATCH 05/21] chore(api-core): remove Python 3.9 from Nox sessions

---
 packages/google-api-core/noxfile.py | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/packages/google-api-core/noxfile.py b/packages/google-api-core/noxfile.py
index 3ae96e416736..9de6a9fc28d2 100644
--- a/packages/google-api-core/noxfile.py
+++ b/packages/google-api-core/noxfile.py
@@ -14,7 +14,7 @@
 
 # Helpful notes for local usage:
 #   unset PYENV_VERSION
-#   pyenv local 3.14.1 3.13.10 3.12.11 3.11.4 3.10.12 3.9.17
+#   pyenv local 3.14.1 3.13.10 3.12.11 3.11.4 3.10.12
 #   PIP_INDEX_URL=https://pypi.org/simple nox
 
 from __future__ import absolute_import
@@ -34,8 +34,8 @@
 # Black and flake8 clash on the syntax for ignoring flake8's F401 in this file.
 BLACK_EXCLUDES = ["--exclude", "^/google/api_core/operations_v1/__init__.py"]
 
-ALL_PYTHON = ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
-SUPPORTED_PYTHON_VERSIONS = ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
+ALL_PYTHON = ["3.10", "3.11", "3.12", "3.13", "3.14"]
+SUPPORTED_PYTHON_VERSIONS = ["3.10", "3.11", "3.12", "3.13", "3.14"]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
@@ -303,7 +303,7 @@ def default(
         (
             True,
             False,
-            ["3.9", "3.10", "3.11"],
+            ["3.10", "3.11"],
             4,
         ),  # Run proto4 tests with grpcio/grpcio-gcp installed
     ],
@@ -325,8 +325,7 @@ def unit(
         session.log(f"Skipping session for Python {session.python}")
         session.skip()
 
-    # TODO: consider converting the following into a `match` statement once
-    # we drop Python 3.9 support.
+    # consider converting the following into a `match` statement.
     if legacy_proto:
         if legacy_proto == 4:
             # Pin protobuf to a 4.x version to ensure coverage for the legacy code path.

From 283a60e5a6f8e667b1369c3a0ec843ad39468732 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:12:21 -0400
Subject: [PATCH 06/21] docs(api-core): update CONTRIBUTING.rst examples to use
 Python 3.10

---
 packages/google-api-core/CONTRIBUTING.rst | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/packages/google-api-core/CONTRIBUTING.rst b/packages/google-api-core/CONTRIBUTING.rst
index bb3f5f55b166..d6250b839447 100644
--- a/packages/google-api-core/CONTRIBUTING.rst
+++ b/packages/google-api-core/CONTRIBUTING.rst
@@ -21,7 +21,7 @@ In order to add a feature:
   documentation.
 
 - The feature must work fully on the following CPython versions:
-  3.9, 3.10, 3.11, 3.12, 3.13 and 3.14 on both UNIX and Windows.
+  3.10, 3.11, 3.12, 3.13 and 3.14 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -171,11 +171,11 @@ configure them just like the System Tests.
 
    # Run all tests in a folder
    $ cd samples/snippets
-   $ nox -s py-3.8
+   $ nox -s py-3.10
 
    # Run a single sample test
    $ cd samples/snippets
-   $ nox -s py-3.8 -- -k <name of test>
+   $ nox -s py-3.10 -- -k <name of test>
 
 ********************************************
 Note About ``README`` as it pertains to PyPI
@@ -197,14 +197,12 @@ Supported Python Versions
 
 We support:
 
--  `Python 3.9`_
 -  `Python 3.10`_
 -  `Python 3.11`_
 -  `Python 3.12`_
 -  `Python 3.13`_
 -  `Python 3.14`_
 
-.. _Python 3.9: https://docs.python.org/3.9/
 .. _Python 3.10: https://docs.python.org/3.10/
 .. _Python 3.11: https://docs.python.org/3.11/
 .. _Python 3.12: https://docs.python.org/3.12/

From c62b6458004854281d7b02f57b0446d18ba472cf Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:23:45 -0400
Subject: [PATCH 07/21] chore(api-core): use match statement in noxfile.py

---
 packages/google-api-core/noxfile.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/packages/google-api-core/noxfile.py b/packages/google-api-core/noxfile.py
index 9de6a9fc28d2..1cb54f80dbb2 100644
--- a/packages/google-api-core/noxfile.py
+++ b/packages/google-api-core/noxfile.py
@@ -325,12 +325,13 @@ def unit(
         session.log(f"Skipping session for Python {session.python}")
         session.skip()
 
-    # consider converting the following into a `match` statement.
-    if legacy_proto:
-        if legacy_proto == 4:
+    match legacy_proto:
+        case 4:
             # Pin protobuf to a 4.x version to ensure coverage for the legacy code path.
             session.install("protobuf>=4.25.8,<5.0.0")
-        else:
+        case None:
+            pass
+        case _:
             assert False, f"Unknown legacy_proto: {legacy_proto}"
 
     default(

From 12c90ca029bd3110a3776f9f5ea1aa2482398df1 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:27:25 -0400
Subject: [PATCH 08/21] refactor(api-core): remove Python < 3.10 polyfill in
 _python_version_support.py

---
 .../api_core/_python_version_support.py       | 55 ++++++++-----------
 .../testing/constraints-3.9.txt               | 14 -----
 .../testing/constraints-async-rest-3.9.txt    | 20 -------
 3 files changed, 23 insertions(+), 66 deletions(-)
 delete mode 100644 packages/google-api-core/testing/constraints-3.9.txt
 delete mode 100644 packages/google-api-core/testing/constraints-async-rest-3.9.txt

diff --git a/packages/google-api-core/google/api_core/_python_version_support.py b/packages/google-api-core/google/api_core/_python_version_support.py
index 66782bfc9ea8..7d82882063df 100644
--- a/packages/google-api-core/google/api_core/_python_version_support.py
+++ b/packages/google-api-core/google/api_core/_python_version_support.py
@@ -140,38 +140,29 @@ def _flatten_message(text: str) -> str:
     return " ".join(textwrap.dedent(text).strip().split())
 
 
-# TODO(https://github.com/googleapis/python-api-core/issues/835):
-# Remove once we no longer support Python 3.9.
-# `importlib.metadata.packages_distributions()` is only supported in Python 3.10 and newer
-# https://docs.python.org/3/library/importlib.metadata.html#importlib.metadata.packages_distributions
-if sys.version_info < (3, 10):
-
-    def _get_pypi_package_name(module_name):  # pragma: NO COVER
-        """Determine the PyPI package name for a given module name."""
-        return None
-
-else:
-    from importlib import metadata
-
-    @functools.cache
-    def _cached_packages_distributions():
-        return metadata.packages_distributions()
-
-    def _get_pypi_package_name(module_name):
-        """Determine the PyPI package name for a given module name."""
-        try:
-            module_to_distributions = _cached_packages_distributions()
-
-            if module_name in module_to_distributions:  # pragma: NO COVER
-                return module_to_distributions[module_name][0]
-        except Exception as e:  # pragma: NO COVER
-            _LOGGER.info(
-                "An error occurred while determining PyPI package name for %s: %s",
-                module_name,
-                e,
-            )
-
-        return None
+from importlib import metadata
+
+
+@functools.cache
+def _cached_packages_distributions():
+    return metadata.packages_distributions()
+
+
+def _get_pypi_package_name(module_name):
+    """Determine the PyPI package name for a given module name."""
+    try:
+        module_to_distributions = _cached_packages_distributions()
+
+        if module_name in module_to_distributions:  # pragma: NO COVER
+            return module_to_distributions[module_name][0]
+    except Exception as e:  # pragma: NO COVER
+        _LOGGER.info(
+            "An error occurred while determining PyPI package name for %s: %s",
+            module_name,
+            e,
+        )
+
+    return None
 
 
 def _get_distribution_and_import_packages(import_package: str) -> Tuple[str, Any]:
diff --git a/packages/google-api-core/testing/constraints-3.9.txt b/packages/google-api-core/testing/constraints-3.9.txt
deleted file mode 100644
index 98614e25b016..000000000000
--- a/packages/google-api-core/testing/constraints-3.9.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-# This constraints file is used to check that lower bounds
-# are correct in pyproject.toml
-# List *all* library dependencies and extras in this file.
-# Pin the version to the lower bound.
-#
-# e.g., if pyproject.toml has "foo >= 1.14.0, < 2.0.0dev",
-# Then this file should have foo==1.14.0
-googleapis-common-protos==1.63.2
-protobuf==4.25.8
-google-auth==2.14.1
-requests==2.20.0
-grpcio==1.33.2
-grpcio-status==1.33.2
-proto-plus==1.22.3
diff --git a/packages/google-api-core/testing/constraints-async-rest-3.9.txt b/packages/google-api-core/testing/constraints-async-rest-3.9.txt
deleted file mode 100644
index b2aa135cd04a..000000000000
--- a/packages/google-api-core/testing/constraints-async-rest-3.9.txt
+++ /dev/null
@@ -1,20 +0,0 @@
-# This constraints file is used to check that lower bounds
-# are correct in pyproject.toml
-# List *all* library dependencies and extras in this file.
-# Pin the version to the lower bound.
-#
-# e.g., if pyproject.toml has "foo >= 1.14.0, < 2.0.0dev",
-# Then this file should have foo==1.14.0
-googleapis-common-protos==1.63.2
-protobuf==4.25.8
-google-auth==2.35.0
-requests==2.20.0
-grpcio==1.33.2
-grpcio-status==1.33.2
-proto-plus==1.22.3
-# Some tests import aiohttp to test async rest
-# from google-auth[aiohttp]
-#   google-auth[aiohttp] v2.39.0 is the first release that requires aiohttp 3.6.2
-#   see - change: https://github.com/googleapis/google-auth-library-python/blame/9d5c0d81e8e69719a2b4cd034bf1ed5d128fdf0a/setup.py#L35
-#       - release: https://github.com/googleapis/google-auth-library-python/commits/main/?after=9d5c0d81e8e69719a2b4cd034bf1ed5d128fdf0a+104
-aiohttp==3.6.2

From ea68a46edbdebb36e2eba4d7c7c9194ecd09f330 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:27:37 -0400
Subject: [PATCH 09/21] docs(api-core): update example Python version in
 client_info.py

---
 packages/google-api-core/google/api_core/client_info.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/google-api-core/google/api_core/client_info.py b/packages/google-api-core/google/api_core/client_info.py
index f0678d24ba1e..024da1e8eb2e 100644
--- a/packages/google-api-core/google/api_core/client_info.py
+++ b/packages/google-api-core/google/api_core/client_info.py
@@ -45,7 +45,7 @@ class ClientInfo(object):
 
     Args:
         python_version (str): The Python interpreter version, for example,
-            ``'3.9.6'``.
+            ``'3.10.0'``.
         grpc_version (Optional[str]): The gRPC library version.
         api_core_version (str): The google-api-core library version.
         gapic_version (Optional[str]): The version of gapic-generated client

From a7b16638924c91bdb195586803d7c4a1d0a06d8c Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:27:44 -0400
Subject: [PATCH 10/21] refactor(api-core): remove Python 3.9 from tracked
 versions list

---
 .../google/api_core/_python_version_support.py             | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/packages/google-api-core/google/api_core/_python_version_support.py b/packages/google-api-core/google/api_core/_python_version_support.py
index 7d82882063df..ee2288a6f35a 100644
--- a/packages/google-api-core/google/api_core/_python_version_support.py
+++ b/packages/google-api-core/google/api_core/_python_version_support.py
@@ -71,13 +71,6 @@ class VersionInfo(NamedTuple):
 
 PYTHON_VERSIONS: List[VersionInfo] = [
     # Refer to https://devguide.python.org/versions/ and the PEPs linked therefrom.
-    VersionInfo(
-        version="3.9",
-        python_beta=datetime.date(2020, 5, 18),
-        python_start=datetime.date(2020, 10, 5),
-        python_eol=datetime.date(2025, 10, 5),
-        gapic_end=datetime.date(2025, 10, 5) + datetime.timedelta(days=90),
-    ),
     VersionInfo(
         version="3.10",
         python_beta=datetime.date(2021, 5, 3),

From 0652eb3ed2c0196e2d430fa2cb759cc7c0d8d377 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:27:53 -0400
Subject: [PATCH 11/21] docs(api-core): update example Python version in
 gapic_v1/client_info.py

---
 .../google-api-core/google/api_core/gapic_v1/client_info.py     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/google-api-core/google/api_core/gapic_v1/client_info.py b/packages/google-api-core/google/api_core/gapic_v1/client_info.py
index 4b3b56493f8a..2cf07840b39b 100644
--- a/packages/google-api-core/google/api_core/gapic_v1/client_info.py
+++ b/packages/google-api-core/google/api_core/gapic_v1/client_info.py
@@ -33,7 +33,7 @@ class ClientInfo(client_info.ClientInfo):
 
     Args:
         python_version (str): The Python interpreter version, for example,
-            ``'3.9.6'``.
+            ``'3.10.0'``.
         grpc_version (Optional[str]): The gRPC library version.
         api_core_version (str): The google-api-core library version.
         gapic_version (Optional[str]): The version of gapic-generated client

From 2d87e660cf97ffe0971524834c5c2087141c9140 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 07:34:45 -0400
Subject: [PATCH 12/21] test(api-core): update tests to use Python 3.10 instead
 of 3.9

---
 .../google-api-core/tests/unit/test_python_version_support.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/google-api-core/tests/unit/test_python_version_support.py b/packages/google-api-core/tests/unit/test_python_version_support.py
index 76eb821e0205..07620934c93f 100644
--- a/packages/google-api-core/tests/unit/test_python_version_support.py
+++ b/packages/google-api-core/tests/unit/test_python_version_support.py
@@ -164,7 +164,7 @@ def test_all_tracked_versions_and_date_scenarios(
 
 def test_override_gapic_end_only():
     """Test behavior when only gapic_end is manually overridden."""
-    version_tuple = (3, 9)
+    version_tuple = (3, 10)
     original_info = PYTHON_VERSION_INFO[version_tuple]
     mock_py_version = VersionInfoMock(major=version_tuple[0], minor=version_tuple[1])
 
@@ -199,7 +199,7 @@ def test_override_gapic_end_only():
 
 def test_override_gapic_deprecation_only():
     """Test behavior when only gapic_deprecation is manually overridden."""
-    version_tuple = (3, 9)
+    version_tuple = (3, 10)
     original_info = PYTHON_VERSION_INFO[version_tuple]
     mock_py_version = VersionInfoMock(major=version_tuple[0], minor=version_tuple[1])
 

From 2ccd85efda854be104d7ae63a6526551ab93a7be Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 08:21:35 -0400
Subject: [PATCH 13/21] chore(api-core): apply black formatting

---
 .../google/api_core/_python_version_support.py                | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/packages/google-api-core/google/api_core/_python_version_support.py b/packages/google-api-core/google/api_core/_python_version_support.py
index ee2288a6f35a..1430fe222641 100644
--- a/packages/google-api-core/google/api_core/_python_version_support.py
+++ b/packages/google-api-core/google/api_core/_python_version_support.py
@@ -17,6 +17,7 @@
 import datetime
 import enum
 import functools
+from importlib import metadata
 import logging
 import warnings
 import sys
@@ -133,9 +134,6 @@ def _flatten_message(text: str) -> str:
     return " ".join(textwrap.dedent(text).strip().split())
 
 
-from importlib import metadata
-
-
 @functools.cache
 def _cached_packages_distributions():
     return metadata.packages_distributions()

From 10181b27dfccb06d2d5bbb06f78e60014f9edf76 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 08:32:05 -0400
Subject: [PATCH 14/21] chore(api-core): apply manual updates and add 3.10
 constraints files

---
 packages/google-api-core/README.rst                |  3 +--
 packages/google-api-core/pyproject.toml            |  4 ++--
 .../google-api-core/testing/constraints-3.10.txt   | 14 ++++++++++++++
 .../testing/constraints-async-rest-3.10.txt        | 14 ++++++++++++++
 .../tests/asyncio/test_bidi_async.py               |  8 ++++++++
 5 files changed, 39 insertions(+), 4 deletions(-)
 create mode 100644 packages/google-api-core/testing/constraints-async-rest-3.10.txt

diff --git a/packages/google-api-core/README.rst b/packages/google-api-core/README.rst
index 6e477cd224c4..f5346b279e79 100644
--- a/packages/google-api-core/README.rst
+++ b/packages/google-api-core/README.rst
@@ -21,8 +21,7 @@ Python >= 3.10
 
 Unsupported Python Versions
 ---------------------------
-
-Python == 2.7, Python == 3.5, Python == 3.6, Python == 3.7, Python == 3.8, Python == 3.9.
+Python <= 3.9
 
 The last version of this library compatible with Python 2.7 and 3.5 is
 `google-api-core==1.31.1`.
diff --git a/packages/google-api-core/pyproject.toml b/packages/google-api-core/pyproject.toml
index 698454cbeac3..3d2934b60db5 100644
--- a/packages/google-api-core/pyproject.toml
+++ b/packages/google-api-core/pyproject.toml
@@ -48,7 +48,7 @@ dependencies = [
   "proto-plus >= 1.22.3, < 2.0.0",
   "proto-plus >= 1.25.0, < 2.0.0; python_version >= '3.13'",
   "google-auth >= 2.14.1, < 3.0.0",
-  "requests >= 2.20.0, < 3.0.0",
+  "requests >= 2.33.0",
 ]
 dynamic = ["version"]
 
@@ -60,7 +60,7 @@ Repository = "https://github.com/googleapis/google-cloud-python"
 [project.optional-dependencies]
 async_rest = ["google-auth[aiohttp] >= 2.35.0, < 3.0.0"]
 grpc = [
-  "grpcio >= 1.33.2, < 2.0.0",
+  "grpcio >= 1.80.0",
   "grpcio >= 1.49.1, < 2.0.0; python_version >= '3.11'",
   "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
   "grpcio-status >= 1.33.2, < 2.0.0",
diff --git a/packages/google-api-core/testing/constraints-3.10.txt b/packages/google-api-core/testing/constraints-3.10.txt
index e69de29bb2d1..97712805206a 100644
--- a/packages/google-api-core/testing/constraints-3.10.txt
+++ b/packages/google-api-core/testing/constraints-3.10.txt
@@ -0,0 +1,14 @@
+# This constraints file is used to check that lower bounds
+# are correct in pyproject.toml
+# List *all* library dependencies and extras in this file.
+# Pin the version to the lower bound.
+#
+# e.g., if pyproject.toml has "foo >= 1.14.0, < 2.0.0dev",
+# Then this file should have foo==1.14.0
+googleapis-common-protos==1.63.2
+protobuf==4.25.8
+google-auth==2.35.0
+requests==2.33.0
+grpcio==1.80.0
+grpcio-status==1.33.2
+proto-plus==1.22.3
diff --git a/packages/google-api-core/testing/constraints-async-rest-3.10.txt b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
new file mode 100644
index 000000000000..97712805206a
--- /dev/null
+++ b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
@@ -0,0 +1,14 @@
+# This constraints file is used to check that lower bounds
+# are correct in pyproject.toml
+# List *all* library dependencies and extras in this file.
+# Pin the version to the lower bound.
+#
+# e.g., if pyproject.toml has "foo >= 1.14.0, < 2.0.0dev",
+# Then this file should have foo==1.14.0
+googleapis-common-protos==1.63.2
+protobuf==4.25.8
+google-auth==2.35.0
+requests==2.33.0
+grpcio==1.80.0
+grpcio-status==1.33.2
+proto-plus==1.22.3
diff --git a/packages/google-api-core/tests/asyncio/test_bidi_async.py b/packages/google-api-core/tests/asyncio/test_bidi_async.py
index 10e2ce44444b..3999628138b8 100644
--- a/packages/google-api-core/tests/asyncio/test_bidi_async.py
+++ b/packages/google-api-core/tests/asyncio/test_bidi_async.py
@@ -33,6 +33,14 @@
 from google.api_core import bidi_async
 from google.api_core import exceptions
 
+# TODO: remove this when droppping support for "Python 3.10" and below.
+if sys.version_info <= (3, 10):  # type: ignore[operator]
+
+    def aiter(obj):
+        return obj.__aiter__()
+
+    async def anext(obj):
+        return await obj.__anext__()
 
 
 @pytest.mark.asyncio

From fcb7965b863824fdee5af81dd8681db963812334 Mon Sep 17 00:00:00 2001
From: Chalmer Lowe <chalmerlowe@google.com>
Date: Thu, 7 May 2026 11:08:55 -0400
Subject: [PATCH 15/21] Apply suggestion from @chalmerlowe

---
 packages/google-api-core/noxfile.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/google-api-core/noxfile.py b/packages/google-api-core/noxfile.py
index 1cb54f80dbb2..27b9b9125a0c 100644
--- a/packages/google-api-core/noxfile.py
+++ b/packages/google-api-core/noxfile.py
@@ -329,7 +329,7 @@ def unit(
         case 4:
             # Pin protobuf to a 4.x version to ensure coverage for the legacy code path.
             session.install("protobuf>=4.25.8,<5.0.0")
-        case None:
+        case None | False:
             pass
         case _:
             assert False, f"Unknown legacy_proto: {legacy_proto}"

From 10db3bd04074685968fa157a61189d6d7399bd34 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Fri, 8 May 2026 12:22:29 -0400
Subject: [PATCH 16/21] chore: update google-auth and aiohttp dependencies

---
 packages/google-api-core/pyproject.toml                      | 4 ++--
 .../google-api-core/testing/constraints-async-rest-3.10.txt  | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/packages/google-api-core/pyproject.toml b/packages/google-api-core/pyproject.toml
index 3d2934b60db5..08b09d1d97b3 100644
--- a/packages/google-api-core/pyproject.toml
+++ b/packages/google-api-core/pyproject.toml
@@ -47,7 +47,7 @@ dependencies = [
   "protobuf >= 4.25.8, < 8.0.0",
   "proto-plus >= 1.22.3, < 2.0.0",
   "proto-plus >= 1.25.0, < 2.0.0; python_version >= '3.13'",
-  "google-auth >= 2.14.1, < 3.0.0",
+  "google-auth >= 2.35.0, < 3.0.0",
   "requests >= 2.33.0",
 ]
 dynamic = ["version"]
@@ -58,7 +58,7 @@ Documentation = "https://googleapis.dev/python/google-api-core/latest/"
 Repository = "https://github.com/googleapis/google-cloud-python"
 
 [project.optional-dependencies]
-async_rest = ["google-auth[aiohttp] >= 2.35.0, < 3.0.0"]
+async_rest = ["google-auth[aiohttp] >= 2.35.0, < 3.0.0", "aiohttp >= 3.9.0"]
 grpc = [
   "grpcio >= 1.80.0",
   "grpcio >= 1.49.1, < 2.0.0; python_version >= '3.11'",
diff --git a/packages/google-api-core/testing/constraints-async-rest-3.10.txt b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
index 97712805206a..7afba4e21ede 100644
--- a/packages/google-api-core/testing/constraints-async-rest-3.10.txt
+++ b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
@@ -12,3 +12,8 @@ requests==2.33.0
 grpcio==1.80.0
 grpcio-status==1.33.2
 proto-plus==1.22.3
+# Note: We pin aiohttp to 3.9.0 to avoid deprecation warnings about '@coroutine'
+# decorators which were deprecated since Python 3.8. When older versions of aiohttp
+# load, because they used @coroutine deep inside their internals, the warnings
+# bubble up and cause our nox session to fail.
+aiohttp==3.9.0

From 09950c6cb86ae15b6bba64ace51a87b29d4d04d1 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Fri, 8 May 2026 12:22:32 -0400
Subject: [PATCH 17/21] chore: remove unnecessary polyfills for aiter/anext in
 tests

---
 .../google-api-core/tests/asyncio/test_bidi_async.py  | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/packages/google-api-core/tests/asyncio/test_bidi_async.py b/packages/google-api-core/tests/asyncio/test_bidi_async.py
index 3999628138b8..a39982bf92aa 100644
--- a/packages/google-api-core/tests/asyncio/test_bidi_async.py
+++ b/packages/google-api-core/tests/asyncio/test_bidi_async.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import sys
+
 import asyncio
 
 from unittest import mock
@@ -33,15 +33,6 @@
 from google.api_core import bidi_async
 from google.api_core import exceptions
 
-# TODO: remove this when droppping support for "Python 3.10" and below.
-if sys.version_info <= (3, 10):  # type: ignore[operator]
-
-    def aiter(obj):
-        return obj.__aiter__()
-
-    async def anext(obj):
-        return await obj.__anext__()
-
 
 @pytest.mark.asyncio
 class Test_AsyncRequestQueueGenerator:

From 29e709ac8f7a35842924a86641173e8ce84f3899 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Mon, 11 May 2026 09:40:48 -0400
Subject: [PATCH 18/21] chore(api-core): update constraints to lowest working
 versions for Python 3.10

---
 packages/google-api-core/pyproject.toml                | 10 +++++-----
 packages/google-api-core/testing/constraints-3.10.txt  |  8 ++++----
 .../testing/constraints-async-rest-3.10.txt            |  8 ++++----
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/packages/google-api-core/pyproject.toml b/packages/google-api-core/pyproject.toml
index 08b09d1d97b3..ba4c42eccb1d 100644
--- a/packages/google-api-core/pyproject.toml
+++ b/packages/google-api-core/pyproject.toml
@@ -47,8 +47,8 @@ dependencies = [
   "protobuf >= 4.25.8, < 8.0.0",
   "proto-plus >= 1.22.3, < 2.0.0",
   "proto-plus >= 1.25.0, < 2.0.0; python_version >= '3.13'",
-  "google-auth >= 2.35.0, < 3.0.0",
-  "requests >= 2.33.0",
+  "google-auth >= 2.14.1, < 3.0.0",
+  "requests >= 2.24.0",
 ]
 dynamic = ["version"]
 
@@ -58,12 +58,12 @@ Documentation = "https://googleapis.dev/python/google-api-core/latest/"
 Repository = "https://github.com/googleapis/google-cloud-python"
 
 [project.optional-dependencies]
-async_rest = ["google-auth[aiohttp] >= 2.35.0, < 3.0.0", "aiohttp >= 3.9.0"]
+async_rest = ["google-auth[aiohttp] >= 2.14.1, < 3.0.0", "aiohttp >= 3.9.0"]
 grpc = [
-  "grpcio >= 1.80.0",
+  "grpcio >= 1.41.0",
   "grpcio >= 1.49.1, < 2.0.0; python_version >= '3.11'",
   "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
-  "grpcio-status >= 1.33.2, < 2.0.0",
+  "grpcio-status >= 1.41.0, < 2.0.0",
   "grpcio-status >= 1.49.1, < 2.0.0; python_version >= '3.11'",
   "grpcio-status >= 1.75.1, < 2.0.0; python_version >= '3.14'",
 ]
diff --git a/packages/google-api-core/testing/constraints-3.10.txt b/packages/google-api-core/testing/constraints-3.10.txt
index 97712805206a..444eb4f13dcf 100644
--- a/packages/google-api-core/testing/constraints-3.10.txt
+++ b/packages/google-api-core/testing/constraints-3.10.txt
@@ -7,8 +7,8 @@
 # Then this file should have foo==1.14.0
 googleapis-common-protos==1.63.2
 protobuf==4.25.8
-google-auth==2.35.0
-requests==2.33.0
-grpcio==1.80.0
-grpcio-status==1.33.2
+google-auth==2.14.1
+requests==2.25.0
+grpcio==1.41.0
+grpcio-status==1.41.0
 proto-plus==1.22.3
diff --git a/packages/google-api-core/testing/constraints-async-rest-3.10.txt b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
index 7afba4e21ede..b5bf92d008f2 100644
--- a/packages/google-api-core/testing/constraints-async-rest-3.10.txt
+++ b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
@@ -7,10 +7,10 @@
 # Then this file should have foo==1.14.0
 googleapis-common-protos==1.63.2
 protobuf==4.25.8
-google-auth==2.35.0
-requests==2.33.0
-grpcio==1.80.0
-grpcio-status==1.33.2
+google-auth==2.14.1
+requests==2.25.0
+grpcio==1.41.0
+grpcio-status==1.41.0
 proto-plus==1.22.3
 # Note: We pin aiohttp to 3.9.0 to avoid deprecation warnings about '@coroutine'
 # decorators which were deprecated since Python 3.8. When older versions of aiohttp

From 690fee49c82b5802c487377df635be1516f76ba6 Mon Sep 17 00:00:00 2001
From: chalmer lowe <chalmerlowe@google.com>
Date: Mon, 11 May 2026 09:58:08 -0400
Subject: [PATCH 19/21] docs(api-core): simplify docstring in
 grpc_helpers_async.py

---
 packages/google-api-core/google/api_core/grpc_helpers_async.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/google-api-core/google/api_core/grpc_helpers_async.py b/packages/google-api-core/google/api_core/grpc_helpers_async.py
index b615d8a13252..826892a571f9 100644
--- a/packages/google-api-core/google/api_core/grpc_helpers_async.py
+++ b/packages/google-api-core/google/api_core/grpc_helpers_async.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""AsyncIO helpers for :mod:`grpc` supporting 3.10+.
+"""AsyncIO helpers for :mod:`grpc`."""
 
 Please combine more detailed docstring in grpc_helpers.py to use following
 functions. This module is implementing the same surface with AsyncIO semantics.

From 76e9f5760589b0e666eb992ca570804e8efb17a2 Mon Sep 17 00:00:00 2001
From: Chalmer Lowe <chalmerlowe@google.com>
Date: Mon, 11 May 2026 09:59:18 -0400
Subject: [PATCH 20/21] Removes duplicative triple quote.

---
 packages/google-api-core/google/api_core/grpc_helpers_async.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/google-api-core/google/api_core/grpc_helpers_async.py b/packages/google-api-core/google/api_core/grpc_helpers_async.py
index 826892a571f9..780788e4b565 100644
--- a/packages/google-api-core/google/api_core/grpc_helpers_async.py
+++ b/packages/google-api-core/google/api_core/grpc_helpers_async.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""AsyncIO helpers for :mod:`grpc`."""
+"""AsyncIO helpers for :mod:`grpc`.
 
 Please combine more detailed docstring in grpc_helpers.py to use following
 functions. This module is implementing the same surface with AsyncIO semantics.

From 7b8abf4b171bb6e27fecebab21f48bdf9175158c Mon Sep 17 00:00:00 2001
From: Chalmer Lowe <chalmerlowe@google.com>
Date: Mon, 11 May 2026 10:13:50 -0400
Subject: [PATCH 21/21] Updates to ensure minimum versions here match minimums
 in constraints files.

Co-authored-by: Chalmer Lowe <chalmerlowe@google.com>
---
 packages/google-api-core/pyproject.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/google-api-core/pyproject.toml b/packages/google-api-core/pyproject.toml
index ba4c42eccb1d..fa40c6ea7695 100644
--- a/packages/google-api-core/pyproject.toml
+++ b/packages/google-api-core/pyproject.toml
@@ -48,7 +48,7 @@ dependencies = [
   "proto-plus >= 1.22.3, < 2.0.0",
   "proto-plus >= 1.25.0, < 2.0.0; python_version >= '3.13'",
   "google-auth >= 2.14.1, < 3.0.0",
-  "requests >= 2.24.0",
+  "requests >= 2.25.0, < 3.0.0",
 ]
 dynamic = ["version"]
 
@@ -60,7 +60,7 @@ Repository = "https://github.com/googleapis/google-cloud-python"
 [project.optional-dependencies]
 async_rest = ["google-auth[aiohttp] >= 2.14.1, < 3.0.0", "aiohttp >= 3.9.0"]
 grpc = [
-  "grpcio >= 1.41.0",
+  "grpcio >= 1.41.0, < 2.0.0",
   "grpcio >= 1.49.1, < 2.0.0; python_version >= '3.11'",
   "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
   "grpcio-status >= 1.41.0, < 2.0.0",