To PRD

Synthesize what is already decided — grilled idea, glossary, ADRs, design brief, prototype results — into a PRD at docs/prd/<slug>.md. Synthesis, not interview: the decisions exist; this skill writes them down.

Gather what is on record

• The authoritative glossary and decisions — use existing OpenSpec specs/design when present, otherwise the project's glossary/ADR convention. Do not create a second record.
• docs/design/<slug>-brief.md and the handoff doc's Results — screens, actions, prototype deviations ([[z-design-brief]], [[z-design-handoff]]).
• The conversation — decisions resolved during grilling ([[z-grill-with-docs]]).
• The codebase — current state of the modules the feature touches.
• Testing seams — preserve already-approved seams. Otherwise choose the lowest interface that proves the behavior without hiding integration risk, per [[z-testing-strategy]].
• Testing flow — preserve the caller-approved TDD or tests-after choice. Without a prior choice, propose test-first per [[z-testing-strategy]].

Resolve only missing testing decisions; existing approval is sufficient. Present candidate seams and the proposed flow with their trade-offs. Do not reopen a settled choice or re-interview unrelated requirements.

Write the PRD

docs/prd/<slug>.md from assets/prd.template.md. Print the PRD in the conversation instead when the user asks — but decomposition reads the file, so offer to write it before [[z-prd-to-openspec]]. Seven sections: