ucon follows Semantic Versioning 2.0.0 starting with v1.0.0:

• MAJOR (X.0.0) — breaking changes to the public API
• MINOR (1.X.0) — new features, new units, new dimensions (backward-compatible)
• PATCH (1.0.X) — bug fixes, documentation, performance improvements

The public API is everything listed in ucon.__all__ plus:

• All symbols exported by ucon.units and ucon.constants
• Submodule imports documented in the API reference (ucon.maps, ucon.graph, ucon.basis, ucon.contexts, ucon.resolver, ucon.parsing, ucon.packages)
• Integration modules (ucon.integrations.numpy, .pandas, .polars, .pydantic)

Symbols prefixed with _ are internal and may change without notice.

v1.0.x is a Long-Term Support (LTS) release line.

• Security and critical bug fixes for a minimum of 2 years from the v1.0.0 release date.
• No breaking changes within the 1.x series.
• LTS patch releases will be tagged as needed (1.0.1, 1.0.2, ...).

Future major versions (2.0, 3.0) will overlap with the prior LTS line by at least 6 months to allow migration time.

Before removing or renaming a public symbol:

1. The symbol is marked deprecated with a DeprecationWarning for at least one minor release cycle (e.g., deprecated in 1.2, removable in 2.0).
2. The deprecation warning includes a message naming the replacement.
3. Deprecated symbols continue to function identically until removal.

Exceptions: symbols that pose a security risk may be removed in a patch release without a deprecation cycle.

ucon tracks the Python release lifecycle. At any given time, ucon supports all Python versions that have not reached end-of-life.

When a Python version reaches end-of-life, support for it may be dropped in the next minor release of ucon. Dropping a Python version is not considered a breaking change.

• Bugs and feature requests: GitHub Issues
• Security vulnerabilities: See SECURITY.md