Bits of .NET

Turn scattered code comments into beautiful, structured API docs in seconds with this prompt template.

The Prompt Template:

You are a technical documentation expert. Analyze the following code and generate comprehensive API documentation.

**Input Code:**
[PASTE YOUR CODE HERE]

**Output Requirements:**
1. Extract all public methods/endpoints
2. For each endpoint, document:
   - HTTP method and route
   - Purpose (one sentence)
   - Request parameters (name, type, required/optional, description)
   - Request body schema (if applicable)
   - Response format (success and error cases)
   - Example request with curl
   - Example response JSON
3. Group endpoints by resource/controller
4. Use OpenAPI 3.0 format
5. Include authentication requirements

**Format:** Output as markdown with code blocks for examples.

Real Example – C# Controller:

// Paste this code into the prompt:
[ApiController]
[Route("api/[controller]")]
public class UsersController : ControllerBase
{
    // GET api/users/{id}
    [HttpGet("{id}")]
    public async Task<ActionResult> GetUser(int id)
    {
        var user = await _db.Users.FindAsync(id);
        if (user == null) return NotFound();
        return user;
    }
    
    // POST api/users
    [HttpPost]
    public async Task<ActionResult> CreateUser(CreateUserDto dto)
    {
        var user = new User { Name = dto.Name, Email = dto.Email };
        _db.Users.Add(user);
        await _db.SaveChangesAsync();
        return CreatedAtAction(nameof(GetUser), new { id = user.Id }, user);
    }
}

AI Output You’ll Get:

## Users API

### Get User by ID
**Endpoint:** `GET /api/users/{id}`

Retrieves a single user by their unique identifier.

**Parameters:**
- `id` (integer, required): User's unique ID

**Success Response (200):**
```json
{
  "id": 123,
  "name": "John Doe",
  "email": "john@example.com"
}
```

**Error Response (404):**
```json
{
  "error": "User not found"
}
```

**Example Request:**
```bash
curl -X GET https://api.example.com/api/users/123 \
  -H "Authorization: Bearer YOUR_TOKEN"
```

Advanced Version – Generate Postman Collection:

After generating the markdown docs above, create a Postman Collection JSON with:
- All endpoints pre-configured
- Example requests with sample data
- Environment variables for base URL and auth tokens
- Tests for status code validation

Output the collection as importable JSON.

Why This Saves Hours:
Manual API documentation typically takes 15-30 minutes per endpoint. For a 20-endpoint API, that’s 5-10 hours. This prompt does it in 2 minutes. You just review and refine.

Bonus – Keep Docs in Sync:
Add this as a git pre-commit hook to auto-update docs when code changes. Use the AI API programmatically to regenerate docs on every commit to main.