Legacy Support Adjudication

Purpose

Use this skill when reviewing code that may exist mainly for historical compatibility. The goal is to decide whether the support contract is still real, not merely whether the code is locally reachable.

Backward compatibility often spans code, persisted data, mobile clients, public APIs, SDKs, background jobs, queues, feature flags, build systems, and rollback procedures. A safe review must trace those dependencies before approving removal.

The skill returns a concrete verdict with evidence, confidence, risk, and next action:

• RETAIN — the compatibility contract still exists.
• DEPLOY OBSERVABILITY — the path may be removable, but runtime or data evidence is missing.
• DEPRECATE — consumers may still exist; start a formal migration and sunset path.
• QUARANTINE — isolate the compatibility path while preserving behavior and collecting evidence.
• REMOVE — evidence shows the compatibility contract is closed.

Invoke this skill when

A diff, PR, issue, or review discussion includes any of these signals: