chore: drop Python 3.9 support

.github/workflows/test.yml

@@ -79,7 +79,7 @@ jobs:
         # causing BlockingIOError [Errno 35] when spawning subprocess
         os: [ubuntu-latest, windows-latest]
         # Test only min and max supported Python versions for efficiency
-        python-version: ["3.9", "3.13"]
+        python-version: ["3.10", "3.13"]
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 

AGENTS.md

@@ -8,7 +8,7 @@ This document provides comprehensive guidance for AI agents and developers worki
 
 - **Primary Purpose**: Enable pip-based installation of promptfoo for Python-centric environments
 - **Implementation**: Thin wrapper that delegates to the official TypeScript promptfoo package
-- **Requirements**: Python 3.9+ and Node.js 20+
+- **Requirements**: Python 3.10+ and Node.js 20+
 
 ### How It Works
 
@@ -141,7 +141,7 @@ Runs on every PR and push to main:
 - **Smoke Tests**: Integration tests against real CLI (`uv run pytest tests/smoke/`)
 - **Build**: Package build validation
 
-Tests run on multiple Python versions (3.9, 3.13) and OSes (Ubuntu, Windows).
+Tests run on multiple Python versions (3.10, 3.13) and OSes (Ubuntu, Windows).
 
 ### Release Workflow (`.github/workflows/release-please.yml`)
 
@@ -174,9 +174,9 @@ We use **OpenID Connect (OIDC)** for secure, credential-free PyPI publishing:
 
 ### Python Version Support
 
-- **Minimum**: Python 3.9
-- **Tested**: Python 3.9 and 3.13
-- **Target**: `py39` for Ruff and mypy
+- **Minimum**: Python 3.10
+- **Tested**: Python 3.10 and 3.13
+- **Target**: `py310` for Ruff and mypy
 
 ### Code Quality Tools
 
@@ -264,7 +264,7 @@ tests/
 
 CI tests across:
 - **Operating Systems**: Ubuntu, Windows (macOS temporarily excluded due to runner constraints)
-- **Python Versions**: 3.9 (min), 3.13 (max)
+- **Python Versions**: 3.10 (min), 3.13 (max)
 - **Scenarios**: Global promptfoo install vs. npx fallback
 
 ### Running Tests

CONTRIBUTING.md

@@ -16,7 +16,7 @@ This repository is only the thin Python shim that lets people install promptfoo
 
 ### Setup
 
-Requires Python 3.9+, Node.js 20+, and [uv](https://github.com/astral-sh/uv).
+Requires Python 3.10+, Node.js 20+, and [uv](https://github.com/astral-sh/uv).
 
 ```bash
 git clone https://github.com/promptfoo/promptfoo-python.git

README.md

@@ -47,7 +47,7 @@
 
 ### Requirements
 
-- **Python 3.9+** (for this wrapper)
+- **Python 3.10+** (for this wrapper)
 - **Node.js 20+** (required to run promptfoo)
 
 ### Install from PyPI

pyproject.toml

@@ -19,15 +19,14 @@ classifiers = [
     "Topic :: Software Development :: Testing",
     "Topic :: Scientific/Engineering :: Artificial Intelligence",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "posthog>=3.0.0",
     "pyyaml>=6.0.0",
@@ -42,11 +41,6 @@ dev = [
     "types-pyyaml>=6.0.0",
 ]
 
-[tool.uv]
-constraint-dependencies = [
-    "urllib3<2.7; python_full_version < '3.10'",
-]
-
 [project.scripts]
 promptfoo = "promptfoo.cli:main"
 
@@ -75,7 +69,7 @@ packages = ["src/promptfoo"]
 
 [tool.ruff]
 line-length = 120
-target-version = "py39"
+target-version = "py310"
 
 [tool.ruff.lint]
 extend-select = [
@@ -97,7 +91,7 @@ ignore = [
 quote-style = "double"
 
 [tool.mypy]
-python_version = "3.9"
+python_version = "3.10"
 # Enable strict mode for comprehensive type checking
 strict = true
 # Additional strictness beyond --strict
@@ -121,7 +115,7 @@ module = "posthog.*"
 ignore_missing_imports = true
 
 [tool.pyright]
-pythonVersion = "3.9"
+pythonVersion = "3.10"
 pythonPlatform = "All"
 typeCheckingMode = "strict"
 include = ["src/promptfoo"]

src/promptfoo/cli.py

@@ -9,7 +9,7 @@
 import shutil
 import subprocess
 import sys
-from typing import NoReturn, Optional
+from typing import NoReturn
 
 from .telemetry import record_wrapper_used
 
@@ -61,7 +61,7 @@ def _split_path(path_value: str) -> list[str]:
     return entries
 
 
-def _resolve_argv0() -> Optional[str]:
+def _resolve_argv0() -> str | None:
     """Resolve the absolute path of the current script (argv[0])."""
     if not sys.argv:
         return None
@@ -76,7 +76,7 @@ def _resolve_argv0() -> Optional[str]:
     return None
 
 
-def _find_windows_promptfoo() -> Optional[str]:
+def _find_windows_promptfoo() -> str | None:
     """
     Search for promptfoo in standard Windows installation locations.
     Useful when not in PATH.
@@ -127,15 +127,15 @@ def _is_executing_wrapper(found_path: str) -> bool:
     )
 
 
-def _search_path_excluding(exclude_dir: str) -> Optional[str]:
+def _search_path_excluding(exclude_dir: str) -> str | None:
     """Search PATH for promptfoo, excluding the specified directory."""
     path_entries = [entry for entry in _split_path(os.environ.get("PATH", "")) if _normalize_path(entry) != exclude_dir]
     if not path_entries:
         return None
     return shutil.which("promptfoo", path=os.pathsep.join(path_entries))
 
 
-def _find_external_promptfoo() -> Optional[str]:
+def _find_external_promptfoo() -> str | None:
     """Find the external promptfoo executable, avoiding the wrapper itself."""
     # 1. First naive search
     candidate = shutil.which("promptfoo")
@@ -167,7 +167,7 @@ def _requires_shell(executable: str) -> bool:
     return ext.lower() in _WINDOWS_SHELL_EXTENSIONS
 
 
-def _run_command(cmd: list[str], env: Optional[dict[str, str]] = None) -> subprocess.CompletedProcess[bytes]:
+def _run_command(cmd: list[str], env: dict[str, str] | None = None) -> subprocess.CompletedProcess[bytes]:
     """Execute a command, handling shell requirements on Windows."""
     if _requires_shell(cmd[0]):
         return subprocess.run(subprocess.list2cmdline(cmd), shell=True, env=env)

src/promptfoo/environment.py

@@ -10,30 +10,29 @@
 import sys
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Optional
 
 
 @dataclass
 class Environment:
     """Information about the current execution environment."""
 
     os_type: str  # "linux", "darwin", "windows"
-    linux_distro: Optional[str] = None  # "ubuntu", "debian", "rhel", "fedora", "alpine", "arch", etc.
-    linux_distro_version: Optional[str] = None  # e.g., "22.04", "11", "9"
-    cloud_provider: Optional[str] = None  # "aws", "gcp", "azure"
+    linux_distro: str | None = None  # "ubuntu", "debian", "rhel", "fedora", "alpine", "arch", etc.
+    linux_distro_version: str | None = None  # e.g., "22.04", "11", "9"
+    cloud_provider: str | None = None  # "aws", "gcp", "azure"
     is_lambda: bool = False  # AWS Lambda
     is_cloud_function: bool = False  # GCP Cloud Functions or Azure Functions
     is_docker: bool = False
     is_kubernetes: bool = False
     is_wsl: bool = False  # Windows Subsystem for Linux
     is_ci: bool = False
-    ci_platform: Optional[str] = None  # "github", "gitlab", "circleci", "jenkins", etc.
+    ci_platform: str | None = None  # "github", "gitlab", "circleci", "jenkins", etc.
     is_venv: bool = False
     is_conda: bool = False
     has_sudo: bool = False  # Best guess if user has sudo access
 
 
-def _read_probe_file(path: Path) -> Optional[str]:
+def _read_probe_file(path: Path) -> str | None:
     """
     Read an optional environment probe file.
 
@@ -53,7 +52,7 @@ def _read_probe_file(path: Path) -> Optional[str]:
         return None
 
 
-def _detect_linux_distro() -> tuple[Optional[str], Optional[str]]:
+def _detect_linux_distro() -> tuple[str | None, str | None]:
     """
     Detect Linux distribution and version.
 
@@ -122,7 +121,7 @@ def _detect_linux_distro() -> tuple[Optional[str], Optional[str]]:
     return None, None
 
 
-def _detect_cloud_provider() -> Optional[str]:
+def _detect_cloud_provider() -> str | None:
     """
     Detect if running on a cloud provider.
 
@@ -213,7 +212,7 @@ def _detect_wsl() -> bool:
     return Path("/mnt/c").exists() and Path("/proc/version").exists()
 
 
-def _detect_ci() -> tuple[bool, Optional[str]]:
+def _detect_ci() -> tuple[bool, str | None]:
     """
     Detect if running in a CI/CD environment.
 

src/promptfoo/telemetry.py

@@ -11,7 +11,7 @@
 import sys
 import uuid
 from pathlib import Path
-from typing import Any, Optional
+from typing import Any
 
 import yaml
 from posthog import Posthog
@@ -95,7 +95,7 @@ def _get_user_id() -> str:
     return user_id
 
 
-def _get_user_email() -> Optional[str]:
+def _get_user_email() -> str | None:
     """Get the user email from the global config if set."""
     config = _read_global_config()
     account = config.get("account", {})
@@ -106,9 +106,9 @@ class _Telemetry:
     """Internal telemetry client for the promptfoo Python wrapper."""
 
     def __init__(self) -> None:
-        self._client: Optional[Posthog] = None
-        self._user_id: Optional[str] = None
-        self._email: Optional[str] = None
+        self._client: Posthog | None = None
+        self._user_id: str | None = None
+        self._email: str | None = None
         self._initialized = False
 
     @property
@@ -136,7 +136,7 @@ def _ensure_initialized(self) -> None:
         except Exception:
             self._client = None  # Silently fail
 
-    def record(self, event_name: str, properties: Optional[dict[str, Any]] = None) -> None:
+    def record(self, event_name: str, properties: dict[str, Any] | None = None) -> None:
         """Record a telemetry event."""
         if self._disabled:
             return
@@ -181,7 +181,7 @@ def shutdown(self) -> None:
 
 
 # Global singleton instance
-_telemetry: Optional[_Telemetry] = None
+_telemetry: _Telemetry | None = None
 
 
 def _get_telemetry() -> _Telemetry: