• Always run tox from the main tox.venv
• If there is no tox.venv, create one with python -m venv tox.venv, activate it and run pip install tox

Use tox for testing (not pytest directly):

• Test matrix configuration is in tox.ini
• Integration tests: tox -e py3.14-{integration}-v{version}
• Common tests: tox -e py3.14-common

Use tox for type checking (not mypy directly):

• Run tox -e mypy before committing (must pass with zero errors)
• Strict mode enabled (check_untyped_defs, disallow_untyped_defs)

Use tox for linting (not ruff directly):

• tox -e ruff
• Full lint suite: tox -e linters
• Full lint suite must pass before committing

AI commits MUST include:

Co-Authored-By: <agent model name> <noreply@anthropic.com>

Example: Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Do NOT edit these directly — modify source scripts instead:

• tox.ini — generated by scripts/populate_tox/populate_tox.py from scripts/populate_tox/tox.jinja
• .github/workflows/test-integrations-*.yml — generated by scripts/split_tox_gh_actions/split_tox_gh_actions.py
• Regenerate all: scripts/generate-test-files.sh

1. Add minimum version to _MIN_VERSIONS in sentry_sdk/integrations/__init__.py
2. Add config to TEST_SUITE_CONFIG in scripts/populate_tox/config.py
3. Add to group in scripts/split_tox_gh_actions/split_tox_gh_actions.py
4. Run scripts/generate-test-files.sh

• Don't crash applications or swallow exceptions
• Don't mutate object references or alter function signatures
• Don't leak file descriptors or make unexpected DB requests
• Write defensive code
• Use end-to-end tests (not mocks)