API Design & Documentation Generator

API Design & Documentation Generator

Overview

Stop wrestling with API documentation. This AI assistant transforms your API concepts into production-ready specs, comprehensive docs, and working code snippets—in minutes, not days.

Triggers

• 中文触发词：API文档、接口文档、生成OpenAPI、API设计、Swagger文档、接口规范、API教程、GraphQL文档
• English triggers: API documentation, OpenAPI spec, REST API design, Swagger docs, API reference, generate API docs, API guide, mock server

Features

1. API Design Intelligence

• Generate OpenAPI 3.0/3.1 specs from descriptions or existing code
• Validate API designs against best practices (REST maturity, naming conventions)
• Suggest improvements for security, performance, and developer experience
• Convert between OpenAPI, AsyncAPI, and GraphQL SDL

2. Documentation Generation

• Write comprehensive API reference documentation
• Create getting-started guides and tutorials
• Generate authentication and authorization guides
• Produce code samples in 10+ languages (Python, JavaScript, TypeScript, Go, Java, C#, Ruby, PHP, curl, etc.)
• Create Postman collections and Insomnia specifications

3. Mock Server Setup

• Generate mock server code from OpenAPI specs
• Support for static and dynamic mocking
• Create sample request/response pairs
• Set up delay rules for realistic testing

4. API Quality Assurance

• Validate OpenAPI/AsyncAPI syntax
• Check for common anti-patterns
• Ensure backward compatibility
• Generate changelog drafts for API updates

Workflow

API Documentation Workflow

1. INPUT: API description or existing code
   ↓
2. DESIGN: Generate OpenAPI specification
   - Define endpoints
   - Schema definitions
   - Authentication/authorization
   - Error responses
   ↓
3. VALIDATE: Check design quality
   - REST best practices
   - Security considerations
   - Completeness check
   ↓
4. DOCUMENT: Generate comprehensive docs
   - Reference documentation
   - Quick-start guides
   - Code samples
   - Tutorials
   ↓
5. TEST: Create mock server + test cases

Quick API Spec Generation Workflow

Step 1: Describe your API
├── What does it do?
├── Who uses it?
└── What data does it manage?

Step 2: Define endpoints
├── Resources (nouns, not verbs)
├── CRUD operations
└── Query parameters

Step 3: Specify data models
├── Request/response schemas
├── Validation rules
└── Error formats

Step 4: Add security
├── Authentication method
├── Authorization scopes
└── Rate limiting

Step 5: Generate artifacts
├── OpenAPI spec (YAML/JSON)
├── Documentation
└── Code samples

Input Examples

Example 1: API Description to OpenAPI

Input:

Design a REST API for a task management system.
- Users can create, read, update, delete tasks
- Tasks have: title, description, due_date, priority, status, tags
- Support pagination for listing tasks
- Require JWT authentication

Expected Output (OpenAPI 3.0):

openapi: 3.0.3
info:
  title: Task Management API
  version: 1.0.0
  description: API for managing tasks with full CRUD operations

paths:
  /tasks:
    get:
      summary: List all tasks
      parameters:
        - name: page
          in: query
          schema:
            type: integer
            default: 1
        - name: limit
          in: query
          schema:
            type: integer
            default: 20
      responses:
        '200':
          description: List of tasks
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Task'
                  pagination:
                    $ref: '#/components/schemas/Pagination'
    post:
      summary: Create a new task
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required: [title]
              properties:
                title:
                  type: string
                description:
                  type: string
                due_date:
                  type: string
                  format: date
                priority:
                  type: string
                  enum: [low, medium, high]
      responses:
        '201':
          description: Task created

  /tasks/{id}:
    get:
      summary: Get a task by ID
      parameters:
        - name: id
          in: path
          required: true
          schema:
            type: string
      responses:
        '200':
          description: Task details
        '404':
          description: Task not found

components:
  schemas:
    Task:
      type: object
      properties:
        id:
          type: string
        title:
          type: string
        description:
          type: string
        due_date:
          type: string
          format: date
        priority:
          type: string
        status:
          type: string
        tags:
          type: array
          items:
            type: string
    Pagination:
      type: object
      properties:
        page:
          type: integer
        limit:
          type: integer
        total:
          type: integer
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT

Example 2: Generate Documentation from OpenAPI

Input: OpenAPI spec (above YAML)

Expected Output Sections:

# Task Management API Documentation

## Getting Started

### Authentication
All endpoints require a valid JWT token in the Authorization header:

Authorization: Bearer

### Base URL

Production: https://api.tasks.example.com/v1

## Endpoints

### List Tasks
Retrieves a paginated list of all tasks.

**Request**
```bash
curl -X GET "https://api.tasks.example.com/v1/tasks?page=1&limit=20" \
  -H "Authorization: Bearer "

Response

{
  "data": [
    {
      "id": "task_123",
      "title": "Complete API docs",
      "priority": "high",
      "status": "pending"
    }
  ],
  "pagination": {
    "page": 1,
    "limit": 20,
    "total": 45
  }
}

Code Samples

Python

import requests

response = requests.get(
    "https://api.tasks.example.com/v1/tasks",
    headers={"Authorization": "Bearer "}
)
tasks = response.json()

JavaScript

const response = await fetch(
  'https://api.tasks.example.com/v1/tasks',
  {
    headers: { 'Authorization': 'Bearer ' }
  }
);
const { data: tasks } = await response.json();

### Example 3: Code Sample Generation

**Input:** OpenAPI endpoint definition + language (Python)

**Output:** Complete, runnable code snippet with error handling

## Output Templates

### Template: API Reference Page
```markdown
# {Endpoint Name}

{Method} {Path}

## Description
{What this endpoint does}

## Authentication
{Authentication requirements}

## Request}

### Path Parameters
| Name | Type | Required | Description |
|------|------|----------|-------------|
| ... | ... | ... | ... |

### Query Parameters
| Name | Type | Required | Default | Description |
|------|------|----------|---------|-------------|
| ... | ... | ... | ... | ... |

### Request Body
```json
{Request body schema}

Response

200 OK

{Response schema}

400 Bad Request

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Description of the error",
    "details": [...]
  }
}

Examples

Request

curl -X {METHOD} {URL} \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer " \
  -d '{body}'

Response

{response example}

## Best Practices

### For API Design
1. **Use nouns for resources:** `/users` not `/getUsers`
2. **Plural naming:** `/tasks` not `/task`
3. **Nest related resources:** `/users/{id}/tasks`
4. **Version from day one:** `/v1`, `/v2`
5. **Use appropriate HTTP methods:** GET (read), POST (create), PUT (replace), PATCH (update), DELETE (remove)
6. **Return proper status codes:** 200, 201, 400, 401, 403, 404, 500

### For Documentation
1. **Start with getting started:** Don't assume users know your API
2. **Provide runnable examples:** Copy-paste ready code beats prose
3. **Document errors clearly:** Users will hit them
4. **Keep it updated:** Outdated docs are worse than no docs
5. **Include changelog:** Help users track changes

### For Security
1. **Never log sensitive data:** Tokens, passwords, PII
2. **Use HTTPS only:** No exceptions
3. **Implement rate limiting:** Protect your infrastructure
4. **Validate all input:** Never trust client data

## Supported Standards

| Standard | Support Level |
|----------|---------------|
| OpenAPI 3.0 | Full |
| OpenAPI 3.1 | Full |
| AsyncAPI 2.0 | Full |
| GraphQL SDL | Full |
| RAML | Read/Convert |
| Swagger 2.0 | Read/Convert |

## Supported Languages for Code Generation

- Python (requests, httpx)
- JavaScript (fetch, axios)
- TypeScript
- Go (net/http, gorilla)
- Java (HttpClient, OkHttp)
- C# (.NET HttpClient)
- Ruby (Net::HTTP)
- PHP (cURL)
- curl
- Kotlin

## Version History

- **1.0.0** (2026-05-15): Initial release
  - OpenAPI 3.0/3.1 generation
  - Multi-language code samples
  - Documentation generation
  - Basic validation