# Capability Registry **Domain:** Runtime Design / Security **Doc Type:** Canonical Concept Node **Maturity:** Core Design Principle **Related:** [[wiki/Canonical Capability Name|Canonical Capability Name]], [[wiki/Dynamic Dispatch|Dynamic Dispatch]], [[wiki/Permissioned Capability|Permissioned Capability]] --- ## Definition **A capability registry is an explicit catalog of operations a runtime is allowed to resolve and execute.** Each entry connects a canonical name to a contract, implementation, version, effect classification, permission requirements, and availability by host. ## Project Context The registry is the security and interoperability boundary between DO instructions and X implementations. An operation cannot run merely because a language function with a matching name happens to exist. ## Key Insight **A registry turns an open-ended function namespace into a reviewable execution surface.** ## See Also [[wiki/Portable Contract|Portable Contract]], [[wiki/Host Adapter|Host Adapter]], [[wiki/Dynamic Dispatch|Dynamic Dispatch]], [[wiki/Technical Terms|Technical Terms]]