Stitch Manage Design System

This skill is a catalog-normalized import from https://github.com/google-labs-code/stitch-skills at commit 7b53207b94e62911777d53d4238b5f8c88c2b519, source path plugins/stitch-design/skills/manage-design-system. The upstream control file was corrected for this workspace: the verified Stitch MCP surface here is design-system oriented, so screen lookup, screen generation, and screen editing tools must be used only when the current host explicitly exposes them.

When to Use This Skill

• Use when .stitch/DESIGN.md should become a Stitch design system or an existing design system should be listed or applied.
• The task involves Google Stitch project IDs, .stitch/ artifacts, DESIGN.md files, Stitch exports, or Stitch-specific validation.
• The broader stitch-design router points here as the narrowest workflow.

Workflow

1. Create or identify the target project; use create_project only when a new project is appropriate.
2. Inspect .stitch/DESIGN.md for project name, colors, type, shape, component, layout, and anti-pattern rules.
3. For small DESIGN.md files, base64-encode UTF-8 content and call upload_design_md with the numeric project ID; for the bundled helper, pass --generated-by with the calling skill or agent name.
4. Immediately call create_design_system_from_design_md with the returned screen instance id and sourceScreen.
5. Use list_design_systems to confirm the design-system asset exists for the project.
6. Use apply_design_system only with valid selected screen instance id and sourceScreen values.

Local Assets

• examples/, resources/, references/, or reference/ are upstream support material when present. Treat SKILL.md as the source of truth if a support file mentions an unavailable MCP tool.
• scripts/ are optional helpers. On Windows, prefer PowerShell or Node equivalents unless Git Bash or WSL is actually available.
• Keep generated .stitch/ files out of commits unless the user explicitly wants them as durable examples.

Corrected Stitch MCP Surface

Verified in this workspace on 2026-06-15: create_project, upload_design_md, create_design_system_from_design_md, list_design_systems, and apply_design_system. This 2026-07-29 source refresh did not re-verify a broader live MCP surface. Do not claim list_projects, list_screens, get_project, get_screen, generate_screen_from_text, edit_screens, or generate_variants were used unless the current host exposes those exact tools in the active tool list.

Cross-Client Portability

This skill is written to stay usable across GitHub Copilot, Claude Code, and Codex.

• GitHub Copilot: keep the folder in a Copilot-visible skill path or wrap the workflow in project instructions when folder discovery is unavailable.
• Claude Code: keep the folder in a local skills directory or a compatible plugin source.
• Codex: install or sync the folder into $CODEX_HOME/skills/stitch-manage-design-system and restart Codex after major changes.

MCP Availability And Fallback

Preferred MCP Server: Stitch MCP

• Fallback prompt: "Use the Stitch Manage Design System skill without MCP. Follow the documented local or manual fallback, show the selected tool surface, and report the verification evidence."
• Use local .stitch/ artifacts, exported HTML or screenshots, bundled scripts, and the Stitch web UI when the host does not expose the needed Stitch MCP operation.
• Do not claim screen lookup, generation, editing, or variant MCP calls unless those tools are present in the active host tool list.
• Do not claim an MCP operation was used when the active host does not expose it.

Anti-Patterns

• Claiming a Stitch screen-generation, screen-editing, or screen-retrieval MCP call succeeded when the active host does not expose that tool.
• Uploading files, screenshots, HTML, markdown, or design assets to Stitch without user-approved destination and artifact details.
• Reading, printing, storing, or committing Stitch API keys, MCP config secrets, cookies, or credential-bearing files.
• Treating generated design or code as final without local render, syntax, or artifact verification.
• Collapsing this workflow into a broader frontend/design skill when Stitch-specific files, project IDs, or design-system assets matter.

Verification Protocol

Before claiming this skill was applied successfully:

1. Pass/fail: upload_design_md and create_design_system_from_design_md were called in sequence, or fallback evidence is recorded.
2. Pass/fail: list_design_systems returns the expected design-system asset.
3. Pass/fail: apply_design_system calls pass only id and sourceScreen for selected screen instances.
4. Pass/fail: Local metadata records the project ID and design-system asset ID when available.
5. Pressure-test scenario: Repeat the workflow with Stitch MCP screen tools unavailable and confirm the fallback path remains honest and actionable.
6. Success metric: The user can identify the exact artifact, project/design-system target, and verification evidence without relying on unstated MCP behavior.

Related Skills

• stitch-design-md: Use when the task also needs this adjacent Stitch workflow.
• stitch-extract-design-md: Use when the task also needs this adjacent Stitch workflow.
• stitch-taste-design: Use when the task also needs this adjacent Stitch workflow.
• stitch-generate-design: Use when the task also needs this adjacent Stitch workflow.