#Compatibility

Starting with v1.0.0, Resterm follows semantic versioning. The compatibility promise applies to the public Go API as well as the file formats and command-line interfaces that users rely on.

##Stable throughout v1

The following interfaces remain compatible across all v1 releases:

• Every exported identifier in the headless package. This is Resterm's only public Go package. Packages under internal/ are private and may change in any release.
• The names, arguments, and behavior of request file directives, including @name, @profile, @compare, @for-each, @expect, and @setting.
• Existing CLI flags and their behavior.
• Machine-readable headless output, including JSON field names, JUnit structure, and exit codes.
• Configuration identifiers, including key binding action IDs, theme keys, and settings keys. Binding and theme files reject unknown keys, so removing a key would prevent an existing configuration from loading.

##RestermScript deprecations

RestermScript builtins and reserved words have a narrower compatibility policy. They may be removed during v1, but only through the following deprecation process:

• A builtin scheduled for removal is deprecated in one minor release and removed no earlier than the following minor release.
• A deprecated builtin continues to work. The parser reports each use as an editor warning and shows the full warning in the Explain pane.
• The release notes identify every removal and its replacement.

##Outside the compatibility promise

Presentation details may change in any release. This includes status message wording, rendered layout, colours, and log output. Code under internal/ is also not covered.

Minor releases may add directives, builtins, flags, and configuration keys. Older versions ignore unknown @setting keys, so a newly added setting alone will not prevent a request file from loading.