# Toolchain and contribution policies Python 3.10 is the supported floor; CI tests 3.10–3.14 on Linux. Development uses Python 3.12 and Poetry with the committed lock. No distro-system-Python compatibility is claimed. The floor may rise only under [ADR-0004](adr/0004-python-floor-policy.md): after upstream end-of-life, announced one release ahead and recorded as a breaking change. Versions advance one step at a time; the maintainer opens releases. See [stability policy](https://github.com/sebastienrousseau/pain001/blob/main/README.md#stability-guarantees), [contribution rules](https://github.com/sebastienrousseau/pain001/blob/main/CONTRIBUTING.md) and [governance](https://github.com/sebastienrousseau/pain001/blob/main/GOVERNANCE.md).