Stitch Manage Design System

---
name: stitch-manage-design-system
version: "2.0"
last_updated: 2026-08-24
tags: [stitch, design-system, mcp, tokens, ui]
description: "Create, list, and apply Stitch design systems from DESIGN.md using the verified Stitch MCP design-system tools and safe upload fallbacks."
license: "Apache-2.0"
---
# 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.

## 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.

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## 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.

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## MCP Availability And Fallback

Preferred MCP Server: Stitch MCP

- Fallback prompt: "Use the Stitch Manage Design System skill without Stitch MCP. Use the Stitch web UI or bundled upload script for large files when direct MCP upload would exceed model output limits. Show the exact files, commands, manual Stitch UI steps, and verification evidence used before concluding."
- Verified Stitch MCP tools in this workspace are design-system/project oriented; use broader screen tools only when the current host exposes them.
- Use local scripts, exported HTML/screenshots, the Stitch web UI, and project metadata files as the fallback evidence path.

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## Related Skills

- [stitch-design-md](../stitch-design-md/SKILL.md): Use when the task also needs this adjacent Stitch workflow.
- [stitch-extract-design-md](../stitch-extract-design-md/SKILL.md): Use when the task also needs this adjacent Stitch workflow.
- [stitch-taste-design](../stitch-taste-design/SKILL.md): Use when the task also needs this adjacent Stitch workflow.
- [stitch-generate-design](../stitch-generate-design/SKILL.md): Use when the task also needs this adjacent Stitch workflow.