Feb 28, 2026 6 min read

    Auto-Generate API Documentation with AI

    Manually writing API docs is tedious and they're always outdated. Vincony's doc generator creates OpenAPI specs, SDK docs, and interactive examples directly from your codebase — and keeps them in sync.

    API Docs Automation OpenAPI

    The Documentation Problem

    API documentation is critical for adoption, but it's the first thing to fall out of date. Every code change creates a documentation gap. Developers spend an average of 20% of their time writing and maintaining docs — time better spent building features.

    Vincony's AI documentation generator analyzes your actual code — routes, types, middleware, database schemas — and produces comprehensive, accurate documentation automatically. When your code changes, regenerate the docs in seconds.

    Generate OpenAPI Specs from Code

    Point the generator at your API source code and get a complete OpenAPI 3.1 specification:

    generate_docs.ts
    typescript
    import Vincony from 'vincony';

const client = new Vincony({ apiKey: 'YOUR_KEY' });

const docs = await client.docs.generate({
  source: './src/api/',
  format: 'openapi-3.1',
  includeExamples: true,
  inferTypes: true,      // Infer request/response types
  analyzeMiddleware: true // Document auth requirements
});

// Save the generated spec
await docs.save('./docs/openapi.yaml');

console.log(`Generated ${docs.endpoints.length} endpoints`);
console.log(`Documented ${docs.schemas.length} schemas`);

    What Gets Generated

    The AI analyzes your code and generates documentation covering:

    • • Endpoint descriptions — automatically inferred from route handlers and comments
    • • Request/response schemas — extracted from TypeScript types, Zod schemas, or runtime analysis
    • • Authentication requirements — detected from middleware chains
    • • Example requests — realistic, runnable examples for every endpoint
    • • Error responses — all possible error codes and their descriptions
    • • Rate limits & pagination — documented from your middleware configuration

    Example: Express.js API

    Here's a real example. Given this Express route:

    routes/users.ts
    typescript
    // GET /api/users/:id - Get user by ID
router.get('/users/:id', authenticate, async (req, res) => {
  const user = await db.users.findById(req.params.id);
  if (!user) return res.status(404).json({ error: 'User not found' });
  res.json({ data: user, meta: { requestId: req.id } });
});

    Vincony generates this OpenAPI spec automatically:

    Generated OpenAPI spec
    yaml
    /api/users/{id}:
  get:
    summary: Get user by ID
    security:
      - bearerAuth: []
    parameters:
      - name: id
        in: path
        required: true
        schema:
          type: string
          format: uuid
    responses:
      '200':
        description: User found
        content:
          application/json:
            schema:
              type: object
              properties:
                data:
                  $ref: '#/components/schemas/User'
                meta:
                  type: object
                  properties:
                    requestId:
                      type: string
      '404':
        description: User not found

    Generate SDK Documentation

    Beyond OpenAPI specs, generate client SDK documentation with usage examples in multiple languages:

    generate_sdk_docs.py
    python
    import vincony

client = vincony.Client(api_key="YOUR_KEY")

# Generate SDK docs from OpenAPI spec
sdk_docs = client.docs.generate_sdk(
    spec="./docs/openapi.yaml",
    languages=["python", "javascript", "curl"],
    include_quickstart=True,
    include_error_handling=True
)

# Output: markdown docs with examples in each language
sdk_docs.save("./docs/sdk/")
print(f"Generated docs for {len(sdk_docs.languages)} languages")

    CI/CD Integration

    Keep docs in sync with every deployment by adding doc generation to your pipeline:

    .github/workflows/docs.yml
    yaml
    name: Update API Docs
on:
  push:
    branches: [main]
    paths: ['src/api/**']

jobs:
  generate-docs:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Generate API docs
        env:
          VINCONY_API_KEY: ${{ secrets.VINCONY_API_KEY }}
        run: |
          npx vincony-cli docs generate \
            --source src/api/ \
            --output docs/openapi.yaml \
            --format openapi-3.1
      - name: Commit updated docs
        run: |
          git add docs/
          git commit -m "chore: update API docs" || true
          git push

    Getting Started

    API documentation generation is available on all plans. The free Developer plan supports basic doc generation with 100 credits. Power ($54.99/mo) adds SDK doc generation and multi-language examples. Business ($199/mo) includes custom branding, interactive doc hosting, and webhook-triggered regeneration.

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    Try It Free — 100 API Credits

    Start using these tools today with Vincony's free Developer plan.

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