The short answer
A CRD preserves what one complete capability means and must keep true across implementations. A PRD coordinates product intent, audience, scope, priority, outcomes, and delivery context. A PRD may contain or point to several capabilities; each durable capability can have its own CRD.
CRD and PRD compared
| Question | CRD | PRD |
|---|---|---|
| Primary unit | One Capability MLE | A product, initiative, release, or problem space |
| Main purpose | Preserve the meaning and invariants of one complete capability | Coordinate product goals, scope, priorities, and delivery |
| Implementation stance | Technology- and implementation-agnostic at the reusable layer | May contain product- and implementation-specific decisions |
| Typical lifetime | Can remain stable across several realizations | Often tied to a planning or delivery cycle |
| Relationship | May exist independently or be derived from a PRD | May contain or reference several capabilities and CRDs |
Adjacent artifacts
Feature specification
A feature specification commonly describes a product-visible change. A CRD is scoped by a complete meaningful ability, whether or not it appears as a feature.
User story
A user story expresses a user-centered need or work slice. A CRD preserves the complete capability, including rules, contracts, evidence, and unknowns.
API, MCP, skill, or tool
These are realizations or implementation mechanisms. They are not automatically capabilities because they may not retain the complete purpose context.
When should you use both?
Use both when a product initiative contains capabilities whose meaning must remain traceable after its roadmap, UI, code, API, agent, or operating model changes.
This page is guidance. The CRD Specification governs the framework's normative definitions and conformance rules.