Stitch Build Loop

Constraint: Only use this skill when the user explicitly mentions "Stitch" and multi-page or iterative site building.

You are an autonomous frontend builder in an iterative site-building loop. Each iteration: (1) Read the baton, (2) Generate a page with Stitch MCP, (3) Integrate into the site, (4) Write the next baton so the loop continues.

Prerequisites

• Stitch MCP Server (see stitch-setup skill or https://stitch.withgoogle.com/docs/mcp/guide/)
• DESIGN.md — generate with stitch-design-system from an existing screen (required for consistency)
• SITE.md — site vision, Stitch project ID, sitemap, roadmap (create if missing)

The baton system

next-prompt.md is the relay baton between iterations. It tells the loop what page to build next.

Baton format

---
page: about
---

**DESIGN SYSTEM (REQUIRED):**
[Paste DESIGN.md Section 6 here verbatim]

**Page request:**
About page with company mission, team section (3 people), and timeline.

Rules:

• page frontmatter → output filename (about.html)
• The body must include the design system block from DESIGN.md Section 6
• You must update next-prompt.md at the end of every iteration — the loop stops if this is missing

---

Execution protocol

Step 1 — Read the baton

Parse next-prompt.md:

• Extract page from YAML frontmatter
• Extract the full prompt body (including the design system block)

Step 2 — Consult context files

File	What to look for
SITE.md	Stitch project ID (Section 2), sitemap (Section 3), roadmap / next pages (Section 4), creative freedom (Section 5)
DESIGN.md	Section 6 — copy this into every prompt, not just the current one

Check: Do not rebuild pages already in SITE.md sitemap. Do not deviate from the visual language in DESIGN.md.

Step 3 — Generate with Stitch

1. Run list_tools → find Stitch MCP prefix
2. If stitch.json exists, use stored projectId — do not create a new project
3. If no stitch.json, call create_project → save numeric ID to stitch.json
4. Call generate_screen_from_text:
   • projectId: numeric ID (no projects/ prefix)
   • prompt: full baton content including DESIGN SYSTEM block
   • deviceType: match what's in SITE.md or DESIGN.md
5. Call get_screen with numeric projectId + screenId
6. Download HTML: bash scripts/fetch-stitch.sh "[htmlCode.downloadUrl]" "queue/[page].html"
7. Download screenshot: save to queue/[page].png

Step 4 — Integrate into site

1. Move queue/[page].html → site/public/[page].html
2. Fix asset paths (make relative to site/public/)
3. Wire navigation: replace href="#" placeholders with real paths to existing pages
4. Ensure the header/footer matches other pages in the site

Step 4.5 — Visual verification (if Chrome DevTools MCP available)

If chrome* tools are in list_tools:

1. Start local server: npx serve site/public -p 3000
2. Navigate to http://localhost:3000/[page].html
3. Take screenshot, compare against queue/[page].png
4. Stop server

Step 5 — Update SITE.md

• Add [x] [page].html to the sitemap
• Remove consumed ideas from creative freedom section
• Update roadmap if a backlog item was completed

Step 6 — Write the next baton (CRITICAL)

You must update next-prompt.md before completing — the loop stalls if you skip this.

1. Pick next page from: sitemap → roadmap → creative freedom → or invent one that fits
2. Write next-prompt.md with:
   • Valid YAML frontmatter (page: <next-page-name>)
   • **DESIGN SYSTEM (REQUIRED):** block copied verbatim from DESIGN.md Section 6
   • Clear page description

---

File structure

project/
├── next-prompt.md       ← Baton (current task; updated each iteration)
├── stitch.json          ← Stitch project ID (persist between loops!)
├── DESIGN.md            ← From stitch-design-system
├── SITE.md              ← Vision, sitemap, roadmap
├── queue/               ← Staging: [page].html, [page].png
└── site/
    └── public/          ← Production: index.html, about.html, etc.

---

SITE.md template

# Site Vision

[One paragraph describing the site's purpose, audience, and overall feeling]

## Stitch Project

- **Project ID (numeric):** [ID from stitch-mcp-create-project]

## Sitemap

- [ ] index.html — Home
- [ ] about.html — About
- [ ] contact.html — Contact

## Roadmap

1. index.html — main landing page
2. about.html — company/team info
3. contact.html — contact form

## Creative freedom

Additional pages or sections not yet planned...

---

Common pitfalls

• ❌ Forgetting to update next-prompt.md (loop stops)
• ❌ Rebuilding a page already in SITE.md sitemap
• ❌ Omitting DESIGN.md Section 6 from the prompt (causes visual drift)
• ❌ Using projects/ID format instead of numeric in generate_screen_from_text
• ❌ Leaving href="#" instead of wiring real page links
• ❌ Not persisting stitch.json (creates new project every iteration)

---

Troubleshooting

Issue	Fix
Inconsistent visual styles across pages	Keep DESIGN.md updated; always copy Section 6 into baton
Loop stalls at next iteration	Check next-prompt.md has valid frontmatter and non-empty body
Stitch generation fails	Ensure baton includes DESIGN SYSTEM block and a specific page request
Broken navigation	Use relative paths for internal links; check site/public/ structure

---

References

• scripts/fetch-stitch.sh — Reliable GCS HTML downloader
• stitch-design-system — Generate DESIGN.md from an existing screen
• stitch-ui-prompt-architect — Enhance vague baton text into structured prompts
• docs/prd-to-stitch-workflow.md — PRD-driven multi-screen workflow