OpenSpec to Prompts Pipeline

Transform an OpenSpec change phase into actionable UI build prompts through a structured 3-step process.

Overview

This skill orchestrates three sub-skills in sequence:

OpenSpec Phase → [prd-lite + prd-clarifier] → [prd-to-ux] → [ux-spec-to-prompts] → Build Prompts

Input: OpenSpec change-id and phase number Output: Three documents ready for UI generation tools

When to Use

• Starting implementation of an OpenSpec feature phase
• Converting spec requirements into UI build prompts
• User says "run the feature pipeline" or "openspec-to-prompts"
• User wants to prepare a phase for frontend development

Required Inputs

Before starting, confirm these inputs with the user:

Input	Description	Example
change-id	OpenSpec change directory name	add-launch-features
phase	Section number from tasks.md	1 (for "1. Pocket Import")

Pipeline Execution

Pre-Flight: Gather Context

Before running the pipeline, read and understand:

1. Tasks file: openspec/changes/{change-id}/tasks.md

   • Extract the specific phase section (e.g., "## 1. Pocket Import")
   • Note all sub-tasks and requirements

2. Proposal file: openspec/changes/{change-id}/proposal.md

   • Understand the "Why" and context
   • Note any constraints or dependencies

3. Spec files: openspec/changes/{change-id}/specs/{capability}/spec.md

   • Read relevant capability specs
   • Extract scenarios and requirements

Create a summary of the phase for use in Step 1.

Step 1: PRD Generation + Clarification

Invoke: prd-lite skill, then prd-clarifier skill

Process:

1. Generate a demo-grade PRD from the phase requirements
2. Run clarification session (recommend "Long" depth = 20 questions)
3. Document all decisions in the clarification session log

Output file: {change-id}/specs/{capability}/{capability}-prd-clarification-session.md

Example: For phase "1. Pocket Import" in change "add-launch-features":

• Output: add-launch-features/specs/article-import/article-import-prd-clarification-session.md

Step 2: UX Specification

Invoke: prd-to-ux skill

Process:

1. Read the clarification session from Step 1
2. Execute all 6 UX passes (NO shortcuts):
   • Pass 1: Mental Model
   • Pass 2: Information Architecture
   • Pass 3: Affordances
   • Pass 4: Cognitive Load
   • Pass 5: State Design
   • Pass 6: Flow Integrity
3. Generate visual specifications

Output file: {prd-clarification-file}-ux-spec.md (same directory as Step 1 output)

Step 3: Build-Order Prompts

Invoke: ux-spec-to-prompts skill

Process:

1. Read the UX spec from Step 2
2. Extract atomic buildable units
3. Map dependencies between units
4. Sequence by build order (foundation → components → assembly)
5. Generate self-contained prompts

Output file: {capability}-build-prompts.md (same directory)

Output Summary

After completion, report all generated files:

Pipeline Complete: {change-id} Phase {phase}

Generated Files:
1. PRD + Clarifications: {path}
2. UX Specification: {path}
3. Build Prompts: {path}

Next Steps:
- Use build prompts with v0, Bolt, or frontend-design skill
- Update tasks.md with any new requirements discovered
- Update spec.md with new scenarios from clarifications

File Naming Convention

All outputs go in the openspec change's specs directory for the relevant capability:

openspec/changes/{change-id}/specs/{capability}/
├── spec.md                                          # Original spec (don't modify)
├── {capability}-prd-clarification-session.md        # Step 1 output
├── {capability}-prd-clarification-session-ux-spec.md  # Step 2 output
└── {capability}-build-prompts.md                    # Step 3 output

Determining Capability Name

Map phase numbers to capability names by reading the change's spec structure:

Phase	tasks.md Section	Likely Capability
1	"1. Pocket Import"	article-import
2	"2. Browser Extension"	browser-extension
3	"3. Offline Reading"	offline-reading

Check openspec/changes/{change-id}/specs/ for exact capability directory names.

Error Handling

Issue	Resolution
Phase not found in tasks.md	List available phases, ask user to confirm
No specs directory for capability	Create it, or output to change root
User wants to skip clarification	Not allowed - clarification prevents implementation bugs
User wants fewer than 20 questions	Recommend "Long" but accept "Medium" (10) minimum

Important Constraints

1. No shortcuts - Each step must complete fully before the next begins
2. Clarification is mandatory - The questions prevent costly rework
3. UX passes are mandatory - All 6 passes, no skipping to visuals
4. Self-contained prompts - Each build prompt must stand alone
5. Track progress - Use TodoWrite to show pipeline progress

Example Invocation

User: "Run openspec-to-prompts for add-launch-features phase 2"

Response:

1. Read tasks.md section "2. Browser Extension"
2. Read proposal.md for context
3. Read specs/browser-extension/spec.md for requirements
4. Invoke prd-lite → generate PRD
5. Invoke prd-clarifier → clarification questions (Long depth)
6. Invoke prd-to-ux → 6-pass UX spec
7. Invoke ux-spec-to-prompts → build prompts
8. Report all generated files