prd-update

name	prd-update
description	Sync a PRD after prototype changes — updates scope, features, golden examples, and changelog to keep the PRD as a living document.

/prd-update — Sync PRD After Prototype Changes

Keep the PRD in sync with the prototype as it evolves. Prototypes are cheap to iterate; the PRD must keep up or it becomes stale.

Instructions

When the user invokes /prd-update [prd-path] [what-changed], run through all steps in sequence.

If only a name is provided (e.g., "VoiceAgent PRD"), search:

1. Tasks/ directory
2. Context/Document Hub/ directory
3. Use Glob with the name pattern

If [what-changed] is not provided, ask: "What changed in the prototype?"

---

Step 1: Load the PRD

1. Read the existing PRD file
2. Read Context/Reference/writing-styles/prd.md for voice

Step 2: Parse What Changed

Based on the user's description, categorize the changes:

Change Type	Sections to Update
Feature added	Scope (in-scope), Key Features, Golden Examples
Feature cut	Scope (out-of-scope), Key Features
Scope expanded	Scope, Risks, Success Metrics
Scope narrowed	Scope, Key Features
New edge case discovered	Golden Examples, Risks
Architecture changed	Proposed Solution, Feasibility Review
Hypothesis shifted	Success, Working Hypothesis
Prototype rebuilt	Interactive Prototype (what is real vs simulated)

Step 3: Update Affected Sections

For each affected section:

• Edit the content to reflect the change
• Keep the same voice and formatting as the rest of the PRD
• If a change introduces uncertainty, flag with [REVIEW]
• Do NOT touch sections unaffected by the change

Step 4: Update Changelog

Add a new row to the changelog table:

| YYYY-MM-DD | [Description of what changed via /prd-update] |

Step 5: Present Summary

Show a diff-style summary of what was updated:

PRD Updated: [Name]

Changed:
  ~ Scope — added [feature], moved [feature] to out-of-scope
  ~ Golden Examples — added 2 new examples (#6, #7)
  ~ Risks — new risk: [risk name]

Unchanged: Problem, Hypothesis, Milestones, Rollout Plan

Then ask: "Want me to run /prd-ready to check if this is ready for review?"

Key Principles

• Only update what changed — don't rewrite the whole document
• Preserve the original author's voice and structure
• Flag new uncertainties with [REVIEW] rather than inventing answers
• Always add a changelog entry so readers can track evolution