Google Stitch — pack router + credit budget

Remote MCP: https://stitch.googleapis.com/mcp
Setup: Stitch MCP docs
Upstream skill bodies: google-labs-code/stitch-skills (Apache-2.0) — bundled here as stitch-* skills.
Phase map: STITCH_PHASES.json

Credits (~400 / day) — non-negotiable

• Prefer read MCP tools first (list_projects, get_project, list_screens, get_screen, list_design_systems).
• Generate/edit/variant only when the user asked for new or changed UI.
• One strong prompt > many regenerations; batch into one edit_screens when possible.
• Default model GEMINI_3_FLASH; use GEMINI_3_1_PRO only if the user asks.
• Avoid high-count generate_variants unless requested.
• On quota errors: stop and report — no retry-spam.

Phases (load these skills)

Phase	Skills	Purpose
0 Router	stitch-mcp-design (this)	Budget + path choice vs Aura/Figma/Claude Design
1 Prompt	stitch-enhance-prompt, stitch-taste-design	Strengthen brief / taste before spending credits
2 Design	stitch-generate-design, stitch-manage-design-system, stitch-upload-to-stitch	Create/iterate screens & systems in Stitch via MCP
3 Extract	stitch-extract-design-md, stitch-extract-static-html, stitch-design-md, stitch-code-to-design	Pull design DNA / HTML / MD out of Stitch or code
4 Build	stitch-react-components, stitch-shadcn-ui, stitch-react-vite-dashboard, stitch-react-native, stitch-remotion	Implement extracted design in app frameworks
5 Iterate	stitch-loop	Closed-loop refine after verify

Always open the phase skill’s skills/<slug>/SKILL.md (not only this router).

vs Aura / Figma / Claude Design

Canonical copy: repo AGENTS.md § Design path matrix

Path	Skill	When
1D Stitch	this + phase skills	Greenfield NL → Stitch screens → code
1C Aura	aura-screenshot-clone	Clone a live URL/screenshot
1B Figma	Figma MCP / figma-design-to-code	Designer Figma file is SoT
1A Claude Design	claude-design	Claude Design canvas / brand system mockups
Assets	mengto-aura-asset-images	Stock imagery only

MCP setup (Cursor)

User MCP config (%USERPROFILE%\.cursor\mcp.json) — never commit keys:

"stitch": {
  "url": "https://stitch.googleapis.com/mcp",
  "headers": { "X-Goog-Api-Key": "<STITCH_API_KEY>" }
}

Example (no secret): docs/mcp.stitch.example.json

Suggested flow

0. Credit check — skip generate if a local craft skill is enough.
1. Phase 1 prompt skills if the brief is vague.
2. Phase 2 stitch-generate-design (Flash).
3. Phase 3 extract.
4. Phase 4 build into the product.
5. Verify (ui-fix-observe-first / frontend-audit) → Phase 5 stitch-loop if needed.

Security

Never commit API keys. Prefer env STITCH_API_KEY. Revoke in Stitch Settings if leaked.