From 39b36952030bd4b5860f5d3ac16fd299b4a70b2a Mon Sep 17 00:00:00 2001
From: konard <drakonard@gmail.com>
Date: Sun, 2 Aug 2026 20:34:09 +0000
Subject: [PATCH 1/3] Initial commit with task details

Adding .gitkeep for PR creation (default mode).
This file will be removed when the task is complete.

Issue: https://github.com/link-foundation/python-ai-driven-development-pipeline-template/issues/44
---
 .gitkeep | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 .gitkeep

diff --git a/.gitkeep b/.gitkeep
new file mode 100644
index 0000000..6d0f175
--- /dev/null
+++ b/.gitkeep
@@ -0,0 +1 @@
+# .gitkeep file auto-generated at 2026-08-02T20:34:08.964Z for PR creation at branch issue-44-ac3e192dd44c for issue https://github.com/link-foundation/python-ai-driven-development-pipeline-template/issues/44
\ No newline at end of file

From 17082719971c1515cd18f0f3b8ade6faf439081e Mon Sep 17 00:00:00 2001
From: konard <drakonard@gmail.com>
Date: Sun, 2 Aug 2026 20:38:26 +0000
Subject: [PATCH 2/3] test: guard mypy Python 3.9 compatibility

---
 tests/test_project_metadata.py | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 tests/test_project_metadata.py

diff --git a/tests/test_project_metadata.py b/tests/test_project_metadata.py
new file mode 100644
index 0000000..005687d
--- /dev/null
+++ b/tests/test_project_metadata.py
@@ -0,0 +1,28 @@
+"""Regression tests for project package metadata."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from packaging.requirements import Requirement
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def dev_requirement(name: str) -> Requirement:
+    """Return one requirement from the project's ``dev`` dependency group."""
+    pyproject = (ROOT / "pyproject.toml").read_text(encoding="utf-8")
+    dev_group = pyproject.split("dev = [", maxsplit=1)[1].split("]", maxsplit=1)[0]
+    requirement_lines = (
+        line.strip().strip('",') for line in dev_group.splitlines()
+    )
+    requirements = (Requirement(line) for line in requirement_lines if line)
+    return next(requirement for requirement in requirements if requirement.name == name)
+
+
+def test_mypy_dependency_supports_configured_python_target() -> None:
+    """The dev extra must not install mypy versions that reject Python 3.9."""
+    mypy = dev_requirement("mypy")
+
+    assert "1.13.0" in mypy.specifier
+    assert "2.0" not in mypy.specifier

From d5da889ec9fa2205b1cf3db3c936febcc93af443 Mon Sep 17 00:00:00 2001
From: konard <drakonard@gmail.com>
Date: Sun, 2 Aug 2026 20:39:26 +0000
Subject: [PATCH 3/3] fix: pin mypy below version 2

---
 .gitkeep                                        | 1 -
 changelog.d/20260802_issue_44_mypy_python_39.md | 4 ++++
 pyproject.toml                                  | 2 +-
 tests/test_project_metadata.py                  | 4 +---
 4 files changed, 6 insertions(+), 5 deletions(-)
 delete mode 100644 .gitkeep
 create mode 100644 changelog.d/20260802_issue_44_mypy_python_39.md

diff --git a/.gitkeep b/.gitkeep
deleted file mode 100644
index 6d0f175..0000000
--- a/.gitkeep
+++ /dev/null
@@ -1 +0,0 @@
-# .gitkeep file auto-generated at 2026-08-02T20:34:08.964Z for PR creation at branch issue-44-ac3e192dd44c for issue https://github.com/link-foundation/python-ai-driven-development-pipeline-template/issues/44
\ No newline at end of file
diff --git a/changelog.d/20260802_issue_44_mypy_python_39.md b/changelog.d/20260802_issue_44_mypy_python_39.md
new file mode 100644
index 0000000..9a0d9f1
--- /dev/null
+++ b/changelog.d/20260802_issue_44_mypy_python_39.md
@@ -0,0 +1,4 @@
+### Fixed
+
+- Keep the development mypy version below 2.0 while the template supports and
+  type-checks against Python 3.9.
diff --git a/pyproject.toml b/pyproject.toml
index 595125a..bd4fca7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,7 +28,7 @@ classifiers = [
 [project.optional-dependencies]
 dev = [
     "ruff>=0.8.0,<0.9",
-    "mypy>=1.13.0",
+    "mypy>=1.13.0,<2.0",
     "pytest>=8.3.0",
     "pytest-asyncio>=0.24.0",
     "pytest-cov>=6.0.0",
diff --git a/tests/test_project_metadata.py b/tests/test_project_metadata.py
index 005687d..6ecc352 100644
--- a/tests/test_project_metadata.py
+++ b/tests/test_project_metadata.py
@@ -13,9 +13,7 @@ def dev_requirement(name: str) -> Requirement:
     """Return one requirement from the project's ``dev`` dependency group."""
     pyproject = (ROOT / "pyproject.toml").read_text(encoding="utf-8")
     dev_group = pyproject.split("dev = [", maxsplit=1)[1].split("]", maxsplit=1)[0]
-    requirement_lines = (
-        line.strip().strip('",') for line in dev_group.splitlines()
-    )
+    requirement_lines = (line.strip().strip('",') for line in dev_group.splitlines())
     requirements = (Requirement(line) for line in requirement_lines if line)
     return next(requirement for requirement in requirements if requirement.name == name)