Source: https://h2corn.monicz.dev/compatibility/

# Python compatibility and wheels

h2corn supports standard CPython 3.11 and newer, and free-threaded CPython 3.14t and newer. Optimized, interpreter-specific wheels are published for supported standard and free-threaded builds. Generic stable-ABI wheels carry both the standard `abi3` and free-threaded `abi3t` tags, beginning with CPython 3.15/3.15t. Wheels are available for Linux, macOS, and Windows.

## Upgrading

Patch releases preserve documented behavior except for bug and security fixes. Minor releases may add APIs and options. Incompatible changes wait for a major release, normally after at least one minor release with a deprecation warning that names the replacement.

Configuration field names, TOML keys, environment variables, and CLI flags are public interfaces. Unknown `H2CORN_*` variables are rejected so a misspelled or removed setting cannot silently fall back to its default.

`Config` and `RequestPolicy` support pickle using named fields. New releases read released pickle formats; older releases need not read newer formats. Only load pickles from trusted sources.

Install an upgrade as a complete package and restart the supervisor. Application reload does not upgrade the server or re-read its configuration; see [reload behavior](https://h2corn.monicz.dev/deployment/operations/#what-sighup-reloads).