Concept Capsule

Create a concept capsule — a short, precise document that anchors all subsequent work to a shared vocabulary (ubiquitous language, DDD) and a set of constraints (design by contract).

The capsule is the durable semantic authority for a project or feature area. It should change slowly after initial establishment.

Authority boundary

Use the capsule for durable conceptual truths only:

• Glossary terms and boundaries
• Invariants/laws
• One concrete happy path
• Permanent non-goals

Do not use the capsule for:

• Phase status, candidate sequencing, or temporary deferments (milestone owns)
• Confidence tracking or uncertain hypotheses (assumptions ledger owns)
• Decision history with rationale/evidence chronology (roadmap/decisions own)