Compatibility and deprecation policy

1.0 support window

SLYNET 1.0 supports Emacs 27.1 through 30.x and Janet 1.40.x through 1.41.x on GNU/Linux and macOS. CI exercises the complete Emacs/Janet cross product for the pinned releases 1.40.1 and 1.41.1. The project may accept fixes for newer compatible patch releases without changing the minor version.

Janet 1.39.1 is explicitly unsupported. Compatibility verification produced 49 backend test failures around fiber/debug APIs and dependent source-index and RPC behavior; the project therefore fails closed rather than claiming partial or unverified support.

Compatibility promises

Documented Emacs commands, customization variables, keybindings, Janet module entrypoints, and stable wire operations will not be removed in a 1.x patch.
Bug fixes may tighten malformed-input rejection or improve diagnostics.
Internal functions and names containing a double hyphen are not public API.
Protocol operations classified as experimental, workaround, pending-design, or unsupported are not covered by the stable compatibility promise.

Deprecation

A stable public API must be documented as deprecated for at least one minor release before removal. Deprecations include a replacement path and appear in the changelog. Security or correctness defects may require immediate behavior changes, but the release notes must explain the break.

Version policy

Patch: compatible fixes, diagnostics, tests, and documentation.
Minor: backward-compatible features and deprecations.
Major: intentional removal or incompatible public protocol/API changes.

project.janet is the canonical version source. Package headers and release metadata must match it before a tag is created.