Stitch Design Agent#

Autonomous agent that requests designs from Google Stitch via its API and integrates them into the active project. The full flow is:

text

OAuth Token → Design Prompt → Stitch API → Generated Code → Project Integration

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1. Prerequisites#

ResourceWhere to get itGoogle OAuth 2.0 token with cloud-platform scopeStep 2 belowActive project (React / NestJS / any stack)Must already be in the workspaceSTITCH_TOKEN environment variable.env file or agent secret

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2. Obtaining the Google Stitch Token#

Option A — User token (interactive flow)#

bash

# 1. Redirect the user to the authorization URL
GET https://accounts.google.com/o/oauth2/v2/auth
  ?client_id=<CLIENT_ID>
  &redirect_uri=<REDIRECT_URI>
  &response_type=code
  &scope=https://www.googleapis.com/auth/cloud-platform
  &access_type=offline

# 2. Exchange the authorization code for tokens
POST https://oauth2.googleapis.com/token
  grant_type=authorization_code
  &code=<CODE>
  &client_id=<CLIENT_ID>
  &client_secret=<CLIENT_SECRET>
  &redirect_uri=<REDIRECT_URI>

# Response:
# { "access_token": "ya29.xxx", "refresh_token": "1//xxx", "expires_in": 3599 }

Option B — Service Account (headless / CI flow)#

bash

# Generate a signed JWT with the service account key and exchange it:
POST https://oauth2.googleapis.com/token
  grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer
  &assertion=<SIGNED_JWT>

The agent must always read the token from the STITCH_TOKEN environment variable. Never hardcode tokens in source code.

---

3. Calling the Stitch API with a Design Prompt#

Main endpoint#

text

POST https://stitch.googleapis.com/v1/designs:generate
Authorization: Bearer {STITCH_TOKEN}
Content-Type: application/json

Request payload#

json

{
  "prompt": "<natural language description of the desired design>",
  "output_format": "react_component",   // "html" | "react_component" | "vue_component"
  "theme": {
    "primary_color": "#3B82F6",
    "font_family": "Inter"
  },
  "context": {
    "framework": "react",
    "styling": "tailwind"              // "css_modules" | "tailwind" | "styled_components"
  }
}

Example of an effective prompt#

text

"Create a financial summary card component with:
- Total balance prominently displayed at the top
- Small bar chart showing the last 7 days
- Two action buttons: Income and Expense
- Minimalist style with a soft shadow
- Dark mode compatible"

Expected response#

json

{
  "design_id": "dsgn_abc123",
  "component_name": "FinancialSummaryCard",
  "code": "import React from 'react';\n\nexport const FinancialSummaryCard = ...",
  "assets": [],
  "metadata": {
    "tokens_used": 840,
    "framework": "react"
  }
}

---

4. Integrating the Design into the Active Project#

4.1 — Save the component#

typescript

// The agent must:
// 1. Extract `response.code` from the Stitch response
// 2. Determine the correct path based on the project structure

const componentName = response.component_name; // e.g. "FinancialSummaryCard"
const targetPath = `src/components/${componentName}.tsx`;

// 3. Write the file
fs.writeFileSync(targetPath, response.code, 'utf-8');

4.2 — Detect where to import it#

The agent should scan the project to find the most logical integration point:

bash

# Find files that are likely to use the new component
grep -r "Dashboard\|Overview\|Home\|Layout" src/pages --include="*.tsx" -l

4.3 — Insert the import and usage#

typescript

// Add to the target file:
import { FinancialSummaryCard } from '../components/FinancialSummaryCard';

// And in the JSX:
<FinancialSummaryCard />

4.4 — Verify it compiles#

bash

npx tsc --noEmit        # Check TypeScript types
npm run lint -- --fix   # Auto-fix linting issues

---

5. Full Agent Flow (pseudocode)#

typescript

async function stitchDesignFlow(userPrompt: string) {
  // Step 1: Read token
  const token = process.env.STITCH_TOKEN;
  if (!token) throw new Error('STITCH_TOKEN is not configured');

  // Step 2: Request design from Stitch
  const stitchResponse = await fetch(
    'https://stitch.googleapis.com/v1/designs:generate',
    {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${token}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        prompt: userPrompt,
        output_format: 'react_component',
        context: { framework: 'react', styling: 'tailwind' },
      }),
    }
  );

  const design = await stitchResponse.json();

  // Step 3: Save the component
  const filePath = `src/components/${design.component_name}.tsx`;
  fs.writeFileSync(filePath, design.code);

  // Step 4: Find the integration point
  const integrationTarget = await detectIntegrationPoint(design.component_name);

  // Step 5: Inject import and JSX
  await injectComponent(integrationTarget, design.component_name);

  // Step 6: Verify build
  execSync('npx tsc --noEmit');

  return { filePath, integrationTarget };
}

---

6. Error Handling#

ErrorLikely causeAgent action401 UnauthorizedToken expired or invalidAsk the user for a new token or refresh automatically400 Bad RequestPrompt too vague or invalid payloadRefine the prompt and retry429 Too Many RequestsRate limit reachedWait 60s and retryTypeScript errorsGenerated component has incorrect typesFix types manually or request regenerationImport conflictsComponent name already exists in the projectRename with a _v2 suffix

---

7. OpenClaw Configuration#

yaml

# openclaw.config.yml (relevant section)
agents:
  stitch-designer:
    skill: stitch-design-agent
    env:
      STITCH_TOKEN: ${secrets.GOOGLE_STITCH_TOKEN}
    tools:
      - file_write
      - file_read
      - bash
      - web_fetch
    triggers:
      - "design a component"
      - "ask stitch for the design"
      - "integrate UI from stitch"
      - "generate the view for"
      - "create a screen for"

---

8. Important Notes for the Agent#

• Always ask the user for a design prompt before calling Stitch if one was not explicitly provided.
• Tokens live for ~1 hour. If the token expires, use the refresh_token to renew it automatically before retrying.
• Check whether the generated component uses libraries not yet installed (e.g. recharts, framer-motion) and run npm install <pkg> before integrating.
• Respect the project architecture: in hexagonal/modular layouts, components belong in src/modules/<domain>/components/, not at the src/components/ root.
• If the project has its own design system, include in the prompt: "follow the app's existing design system and use its CSS tokens".
• If the generated code references hardcoded colors or sizes that conflict with the existing theme, replace them with the project's CSS variables before saving.