# Canonical Capability Name **Domain:** API Design / Interoperability **Doc Type:** Contract Component **Maturity:** Core Design Principle **Related:** [[wiki/Portable Contract|Portable Contract]], [[wiki/Capability Registry|Capability Registry]] --- ## Definition **A canonical capability name is the stable public identifier for one reusable behavior across implementations and hosts.** Compatibility aliases may preserve older applications, but the canonical name is the reference point for contracts, documentation, fixtures, dispatch, and generated bindings. ## Project Context X originally pursued function-name alignment across languages. The modern continuation makes that alignment explicit: names should identify semantic behavior, not merely resemble one another across PHP, JavaScript, Python, and Perl. ## Key Insight **A stable name is useful only when it points to stable observable behavior.** ## See Also [[wiki/Input Rules|Input Rules]], [[wiki/Normalized Output|Normalized Output]], [[wiki/Dynamic Dispatch|Dynamic Dispatch]], [[wiki/Technical Terms|Technical Terms]]