stitch-mcp-get-screen

Stitch MCP — Get Screen

Retrieves the full output of a Stitch-generated screen: the HTML source code URL and the screenshot image URL. This is the gateway between Stitch design and framework conversion.

Critical prerequisite

Only use this skill when the user explicitly mentions "Stitch".

If you already have both projectId AND screenId, call this directly — do not call get_project first.

When to use

• After list_screens has returned a screenId
• User provides a Stitch screen URL and wants to convert it to code
• Retrieving assets for any conversion skill: Next.js, Svelte, HTML, React Native, or SwiftUI

Step 1: Parse IDs from context

The user may provide the screen reference in different formats:

Input format	→ projectId	→ screenId
projects/123/screens/456	123	456
https://stitch.withgoogle.com/projects/123?node-id=456	123	456
Separate numeric IDs already known	Use as-is	Use as-is

Step 2: Call the MCP tool

Important: Both IDs must be numeric — no projects/ or screens/ prefix.

{
  "name": "get_screen",
  "arguments": {
    "projectId": "3780309359108792857",
    "screenId": "88805abc123def456"
  }
}

✅ projectId: "3780309359108792857"
❌ projectId: "projects/3780309359108792857"

✅ screenId: "88805abc123def456"
❌ screenId: "screens/88805abc123def456"

Output schema

{
  "name": "projects/3780309359108792857/screens/88805abc123def456",
  "htmlCode": {
    "downloadUrl": "https://storage.googleapis.com/stitch-output/..."
  },
  "screenshot": {
    "downloadUrl": "https://storage.googleapis.com/stitch-screenshots/..."
  },
  "figmaExport": {
    "downloadUrl": "https://storage.googleapis.com/stitch-figma/..."
  },
  "width": 390,
  "height": 844,
  "deviceType": "MOBILE"
}

Step 3: Download the HTML reliably

AI fetch tools frequently fail on Google Cloud Storage URLs. Use the bash script:

bash scripts/fetch-stitch.sh "[htmlCode.downloadUrl]" "temp/source.html"

Always quote the URL to handle special characters.

Step 4: Determine framework and route to conversion

After retrieving the screen, check what the user wants to do with it.

Check the deviceType in the response first — it shapes which options to suggest:

deviceType	Sensible defaults to suggest
DESKTOP	Next.js, Svelte, HTML
MOBILE	Next.js (PWA), Svelte, HTML, React Native, SwiftUI
AGNOSTIC	Any

Then route based on user intent:

User intent	→ Load skill
"Convert to Next.js", "React app", "App Router"	stitch-nextjs-components
"Convert to Svelte", "SvelteKit"	stitch-svelte-components
"Convert to HTML", "PWA", "Capacitor", "Ionic", "web app"	stitch-html-components
"React Native", "Expo", "iOS and Android", "cross-platform"	stitch-react-native-components
"SwiftUI", "Xcode", "native iOS", "iOS only"	stitch-swiftui-components
"Extract design system", "get the colors/fonts"	stitch-design-system
"Just show me the screenshot"	Present screenshot.downloadUrl
No framework mentioned, desktop design	Ask: Next.js, Svelte, or HTML?
No framework mentioned, mobile design	Ask: React Native, SwiftUI, or HTML (Capacitor)?

References

• scripts/fetch-stitch.sh — Reliable GCS HTML downloader