# Capability-Oriented Architecture **Domain:** Software Architecture / Libraries **Doc Type:** Canonical Concept Node **Maturity:** Developing **Related:** [[wiki/Portable Contract|Portable Contract]], [[wiki/Capability Registry|Capability Registry]], [[wiki/Host Adapter|Host Adapter]] --- ## Definition **Capability-oriented architecture organizes reusable behavior as named, bounded operations rather than as incidental methods trapped inside one application.** Each capability has an interface, implementation, tests, and an explicit relationship to host effects. ## Project Context Shazam placed one Perl function in each module and generated alternate consumption forms. X expanded the objective toward aligned implementations in JavaScript, PHP, Python, and Perl. XDO composes only registered capabilities so readable documents can request work without receiving arbitrary code execution. ## Key Insight **A capability is portable when its behavior is defined independently of the host that exposes it.** ## See Also [[projects/Shazam - A Portable Perl Capability Library|Shazam]], [[projects/X and XApps - Drop the Folder and It Runs|X and XApps]], [[wiki/Permissioned Capability|Permissioned Capability]], [[wiki/Technical Terms|Technical Terms]]