Quick Design — Light Spec

For changes where opening /design-system would be heavyweight: copy tweaks, single-control re-designs, paywall-position changes, debounce tuning, error-message rewrites. The spec ends up embedded inside a story file, not as a standalone PRD.

Purpose / When to Run

Run when:

• A change is too small to update a full PRD section
• The PRD for the affected system is already complete and the change is a delta
• A bug fix has product implications worth recording
• The user types /quick-design for a one-off tweak

Do not run when:

• The change crosses multiple systems → use /design-system
• The change introduces a new system → use /design-system
• The change has no PRD context at all → use /design-system from scratch

Inputs

• Change name (required)
• Optional --story <path> to embed the spec into a specific story
• Existing PRD for the affected system if any
• design/concept.md

Outputs

Either:

• A standalone design/quick/<change-name>.md, OR
• An appended ## Quick Design Spec block inside the named story file

Phase 1: Argument Resolution

If no change name is provided, ask:

• Prompt: "What is the change?"
• Free text — capture as kebab-case for filename.

Detect parent PRD: ask the user which existing PRD this change touches. Use Glob design/prd/*.md and offer the list as AskUserQuestion options if they don't know.

Detect mode:

• --story <path> provided → embed mode
• No flag → standalone mode (writes design/quick/<change-name>.md)

Phase 2: Lightweight Context

Read only what is needed:

• The parent PRD section the change affects (not the whole PRD)
• The story file if embed mode
• Relevant entries in design/design-bible.md if the change is visual

Print a one-line context summary: "Change touches PRD <system>, section <name>. Embedding into story <NNN>."

Phase 3: Capture the Spec

Use a compact Q&A loop. Each question maps to a section of the spec.

1. What is changing? (one sentence)
2. Why? — link to a bug, metric goal, user feedback, or concept-doc principle
3. Specifically what is the new behavior? — exact copy / value / sequence / position
4. What is replaced? — exact prior behavior, so the diff is unambiguous
5. Who does this affect? — all users / new users only / paying users / specific cohort
6. Are there edge cases? — minimum required: offline, accessibility, dark mode if visual
7. How will we know it worked? — one or two acceptance criteria in GIVEN-WHEN-THEN

Use AskUserQuestion for cohort question (closed list); free text for the rest.

For visual / copy changes, also ask:

• "Copy: provide the exact final text" (free text)
• "Visual: any token changes from the design bible? Which?" (AskUserQuestion with bible token names if bible exists)

For threshold / parameter changes, also ask:

• "Old value, new value, valid range, who can change it without a release?"

Phase 4: Draft the Spec

Build a compact block:

## Quick Design Spec — <Change Name>

> **Created**: <date>
> **Affects PRD**: `design/prd/<system>.md` § <section>
> **Cohort**: <all / new / paying / specific>

### Change
<one paragraph — what is changing and why>

### Behavior diff
**Before:** <exact prior behavior>
**After:** <exact new behavior>

### Edge cases
- <list, mobile-relevant>

### Acceptance criteria
- **GIVEN** <state> **WHEN** <action> **THEN** <observable result>

### Notes
- <any callouts — feature flag name, A/B test, kill switch, instrumentation event>

Keep this under 30 lines. If it grows past that, recommend converting to a full PRD update.

Phase 5: Approval & Write

Show the draft. Ask via AskUserQuestion:

• Prompt: "Approve and write this spec?"
• Options:
  • Approve — write to story (if embed mode)
  • Approve — write to design/quick/<name>.md (if standalone)
  • Make changes — describe
  • Discard

If embed mode: append the block to the story file using Edit, anchoring to the end of ## Acceptance Criteria or the bottom of the file.

If standalone: write the file with a header # Quick Design — <name> plus the block.

After write:

• Update the parent PRD's "Open Questions" section to note "see quick spec at <path>" if a tracking link is useful
• Update production/session-state/active.md

Phase 6: Suggest Next

Print:

"Quick spec written. If this change should ship in the active sprint, run /sprint-plan (or update the existing sprint plan)."

If embed mode: also note "Story <path> now has the embedded spec — run /story-readiness <path> before implementation."

Edge Cases

• The "small" change keeps growing: pause after question 3 if the change is touching more than one system or 3+ screens. Recommend /design-system instead.
• No parent PRD: the change is too foundational for quick-design; redirect to /design-system.
• The user wants the spec but not the story embed: write standalone. The story can reference the path later.

Quality Gates

• The spec must include at least one acceptance criterion in GIVEN-WHEN-THEN form
• The before/after diff must be exact — no "improve" language without the specific change
• For copy changes, the exact final string is captured verbatim
• For threshold changes, old value + new value + range are all specified

Examples

/quick-design empty-state-copy --story production/epics/onboarding/story-007-add-list.md

• Change: rewrite the empty state on the lists screen
• Before: "No lists yet."
• After: "Tap + to start your first list — it takes about 10 seconds."
• Acceptance: GIVEN a new account WHEN the user opens the lists screen THEN the new copy is shown.
• Embedded into the story file.

/quick-design paywall-trigger-timing

• Change: paywall now triggers after the 3rd successful action, not the 1st app launch
• Standalone spec written to design/quick/paywall-trigger-timing.md
• Acceptance: GIVEN a free-tier user has completed 3 actions WHEN they attempt the 4th THEN the paywall is shown
• Notes: feature-flag paywall_trigger_v2, A/B test against current behavior