API Documentation Template Generator

Generate comprehensive API documentation for REST endpoints.

Document Structure

# API Reference

## Overview
{API description and base URL}

## Authentication
{Auth methods}

## Endpoints

### {Resource}
- [GET /{resource}](#get-resource)
- [POST /{resource}](#post-resource)
- [GET /{resource}/{id}](#get-resource-id)
- [PUT /{resource}/{id}](#put-resource-id)
- [DELETE /{resource}/{id}](#delete-resource-id)

## Error Handling
{Error format and codes}

## Rate Limiting
{Rate limit info}

Section Templates

Overview Section

## Overview

**Base URL:** `https://api.example.com/v1`

**Content Type:** `application/json`

**API Version:** v1 (2025-01-15)

### Request Format

All requests should include:
- `Content-Type: application/json` header
- Authentication header (see Authentication section)
- Request body as JSON for POST/PUT requests

Authentication Section

## Authentication

### Bearer Token

Include the token in the Authorization header:

```http
Authorization: Bearer {token}

API Key

Include the API key in the X-API-Key header:

X-API-Key: {api_key}

Obtaining Tokens

POST /auth/token
Content-Type: application/json

{
    "email": "user@example.com",
    "password": "secret"
}

Response:

{
    "token": "eyJhbGciOiJIUzI1NiIs...",
    "expires_at": "2025-01-16T12:00:00Z"
}

### Endpoint Template

```markdown
## {HTTP Method} /{path}

{Brief description of what this endpoint does}

### Request

**URL:** `{HTTP Method} /api/v1/{path}`

**Authentication:** Required / Optional

#### Path Parameters

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `{param}` | {type} | Yes/No | {description} |

#### Query Parameters

| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `{param}` | {type} | {default} | {description} |

#### Request Body

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `{field}` | {type} | Yes/No | {description} |

**Example Request:**

```http
{METHOD} /api/v1/{path}
Authorization: Bearer {token}
Content-Type: application/json

{
    "field": "value"
}

Response

Success Response: {status code} {status text}

Field	Type	Description
{field}	{type}	{description}

Example Response:

{
    "id": "123",
    "field": "value",
    "created_at": "2025-01-15T10:00:00Z"
}

Errors

Status	Code	Description
400	VALIDATION_ERROR	Invalid request body
401	UNAUTHORIZED	Missing or invalid token
404	NOT_FOUND	Resource not found
422	UNPROCESSABLE	Business rule violation

### Error Handling Section

```markdown
## Error Handling

### Error Response Format

All errors follow this format:

```json
{
    "error": {
        "code": "ERROR_CODE",
        "message": "Human-readable error message",
        "details": {
            "field": ["Specific field error"]
        }
    }
}

HTTP Status Codes

Status	Meaning
200	OK - Request succeeded
201	Created - Resource created
204	No Content - Successful deletion
400	Bad Request - Invalid syntax
401	Unauthorized - Invalid credentials
403	Forbidden - Insufficient permissions
404	Not Found - Resource doesn't exist
422	Unprocessable Entity - Validation failed
429	Too Many Requests - Rate limit exceeded
500	Internal Server Error - Server error

Common Error Codes

Code	Description
VALIDATION_ERROR	Request validation failed
UNAUTHORIZED	Authentication required
FORBIDDEN	Insufficient permissions
NOT_FOUND	Resource not found
CONFLICT	Resource already exists
RATE_LIMITED	Too many requests

### Rate Limiting Section

```markdown
## Rate Limiting

API requests are rate limited per API key:

| Plan | Limit | Window |
|------|-------|--------|
| Free | 100 | per hour |
| Pro | 1000 | per hour |
| Enterprise | 10000 | per hour |

### Rate Limit Headers

| Header | Description |
|--------|-------------|
| `X-RateLimit-Limit` | Maximum requests allowed |
| `X-RateLimit-Remaining` | Requests remaining |
| `X-RateLimit-Reset` | Unix timestamp when limit resets |

### Rate Limit Response

When rate limited, you'll receive:

```http
HTTP/1.1 429 Too Many Requests
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 1705320000

{
    "error": {
        "code": "RATE_LIMITED",
        "message": "Rate limit exceeded. Retry after 60 seconds."
    }
}

## Complete Endpoint Example

```markdown
## POST /orders

Create a new order for the authenticated user.

### Request

**URL:** `POST /api/v1/orders`

**Authentication:** Required

#### Request Body

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `items` | array | Yes | Order items |
| `items[].product_id` | string | Yes | Product UUID |
| `items[].quantity` | integer | Yes | Quantity (1-100) |
| `shipping_address` | object | Yes | Delivery address |
| `shipping_address.street` | string | Yes | Street address |
| `shipping_address.city` | string | Yes | City name |
| `shipping_address.postal_code` | string | Yes | Postal/ZIP code |
| `shipping_address.country` | string | Yes | ISO 3166-1 alpha-2 |
| `coupon_code` | string | No | Discount code |

**Example Request:**

```http
POST /api/v1/orders
Authorization: Bearer eyJhbGci...
Content-Type: application/json

{
    "items": [
        {
            "product_id": "550e8400-e29b-41d4-a716-446655440000",
            "quantity": 2
        }
    ],
    "shipping_address": {
        "street": "123 Main St",
        "city": "New York",
        "postal_code": "10001",
        "country": "US"
    },
    "coupon_code": "SAVE10"
}

Response

Success Response: 201 Created

Field	Type	Description
id	string	Order UUID
status	string	Order status
items	array	Order items with prices
subtotal	object	Subtotal amount
discount	object	Discount amount
total	object	Total amount
created_at	string	ISO 8601 timestamp

Example Response:

{
    "id": "ord_123456",
    "status": "pending",
    "items": [
        {
            "product_id": "550e8400-e29b-41d4-a716-446655440000",
            "name": "Widget Pro",
            "quantity": 2,
            "unit_price": {"amount": 2999, "currency": "USD"},
            "total": {"amount": 5998, "currency": "USD"}
        }
    ],
    "subtotal": {"amount": 5998, "currency": "USD"},
    "discount": {"amount": 600, "currency": "USD"},
    "total": {"amount": 5398, "currency": "USD"},
    "shipping_address": {
        "street": "123 Main St",
        "city": "New York",
        "postal_code": "10001",
        "country": "US"
    },
    "created_at": "2025-01-15T10:30:00Z"
}

Errors

Status	Code	Description
400	INVALID_PRODUCT	Product ID is malformed
404	PRODUCT_NOT_FOUND	Product doesn't exist
422	OUT_OF_STOCK	Insufficient inventory
422	INVALID_COUPON	Coupon code invalid or expired
422	MIN_ORDER_VALUE	Order below minimum value

## Generation Instructions

When generating API documentation:

1. **Identify** all endpoints from routes or actions
2. **Document** request parameters (path, query, body)
3. **Document** response fields with types
4. **Provide** realistic example requests/responses
5. **List** all possible error responses
6. **Include** authentication requirements
7. **Group** endpoints by resource