stitch-kit Setup Guide

Walks users through two setup tasks:

1. Stitch MCP Server — connect your AI client to Google Stitch's remote generation API
2. stitch-kit Plugin — install the skills that orchestrate the Stitch workflow

When to use this skill

• User says "how do I set this up", "it's not working", "Stitch isn't available"
• Agent can't find Stitch MCP tools after running list_tools
• First-time setup in a new environment

Step 1: Verify what's already installed

Run list_tools (or check the tool list). Look for any of:

• create_project
• generate_screen_from_text
• get_screen

If found: Stitch MCP is working. Skip to Step 4 (plugin install). If not found: Continue with MCP setup below.

Step 2: Get a Stitch API Key

Stitch MCP is a remote HTTP server — it lives in the cloud at stitch.googleapis.com, not on your machine. It requires an API key to authenticate.

1. Go to stitch.withgoogle.com/settings
2. Scroll to the API Keys section
3. Click "Create API Key"
4. Copy the key — you'll need it in the next step

Never commit your API key to a public repository. Store it securely.

Step 3: Configure Stitch MCP

Claude Code

Using the CLI (recommended):

claude mcp add stitch --transport http https://stitch.googleapis.com/mcp \
  --header "X-Goog-Api-Key: YOUR-API-KEY" -s user

Or add to ~/.claude/settings.json manually:

{
  "mcpServers": {
    "stitch": {
      "type": "http",
      "url": "https://stitch.googleapis.com/mcp",
      "headers": {
        "X-Goog-Api-Key": "YOUR-API-KEY"
      }
    }
  }
}

Codex CLI

Add to ~/.codex/config.toml:

[mcp_servers.stitch]
url = "https://stitch.googleapis.com/mcp"

[mcp_servers.stitch.headers]
X-Goog-Api-Key = "YOUR-API-KEY"

Cursor

Create or edit .cursor/mcp.json:

{
  "mcpServers": {
    "stitch": {
      "url": "https://stitch.googleapis.com/mcp",
      "headers": {
        "X-Goog-Api-Key": "YOUR-API-KEY"
      }
    }
  }
}

VS Code

Open Command Palette → "MCP: Add Server" → HTTP → https://stitch.googleapis.com/mcp → name: "stitch". Then edit the generated mcp.json to add the header:

{
  "servers": {
    "stitch": {
      "url": "https://stitch.googleapis.com/mcp",
      "type": "http",
      "headers": {
        "Accept": "application/json",
        "X-Goog-Api-Key": "YOUR-API-KEY"
      }
    }
  }
}

Quick install (all platforms)

Or use the NPX installer — it prompts for the API key and configures everything:

npx @booplex/stitch-kit

Manual verification

After adding, restart the client and run list_tools. You should see tools like create_project, generate_screen_from_text, get_screen, etc.

Step 4: Install stitch-kit plugin (Claude Code)

/plugin marketplace add https://github.com/gabelul/stitch-kit.git
/plugin install stitch-kit@stitch-kit

All 34 skills in one command. The stitch-kit agent is included — it shows up automatically after restart.

Step 5: Verify the full setup

Run the orchestrator to confirm everything works:

"Use Stitch to design a simple login screen"

Expected behavior:

1. stitch-orchestrator activates
2. It runs list_tools and finds Stitch MCP tools
3. It generates a Design Spec
4. It creates a project via create_project
5. It generates a screen via generate_screen_from_text
6. It retrieves the screen via get_screen
7. It asks you which framework to convert to

If this completes, you're fully set up.

Troubleshooting

Network requirements

Stitch MCP makes outbound requests to:

• stitch.googleapis.com — remote MCP server
• storage.googleapis.com — file downloads (HTML, screenshots)
• accounts.google.com — OAuth (if using OAuth instead of API key)

If you're behind a corporate proxy or VPN, ensure these domains are allowed.

Offline / no-MCP mode

If you cannot configure Stitch MCP, the orchestrator still works in prompt-only mode:

• Steps 1–3 run normally (spec generation, prompt assembly)
• Instead of generating the screen, it outputs a ready-to-copy Stitch prompt
• You paste that prompt at stitch.withgoogle.com manually
• Then you can still use the conversion skills on the downloaded HTML

Authentication alternatives

OAuth (for restricted environments)

If you can't store API keys on disk, Stitch supports OAuth via Google Cloud:

gcloud auth login
gcloud auth application-default login
gcloud config set project YOUR-PROJECT-ID
gcloud beta services mcp enable stitch.googleapis.com --project=YOUR-PROJECT-ID

Then use Bearer token auth instead of API key. See full OAuth guide.

Note: OAuth tokens expire hourly and need manual refresh. API keys are simpler for most users.

References

• Official Stitch MCP setup: https://stitch.withgoogle.com/docs/mcp/setup
• Plugin repo: https://github.com/gabelul/stitch-kit
• Skills index: docs/skills-index.md
• MCP tool reference: docs/mcp-naming-convention.md