ln-775-api-docs-generator Skill

ln-775-api-docs-generator

Type: L3 Worker Category: 7XX Project Bootstrap Parent: ln-770-crosscutting-setup

Configures API documentation with Swagger/OpenAPI.

Overview

| Aspect | Details | |--------|---------| | Input | Context Store from ln-770 | | Output | Swagger/OpenAPI configuration | | Stacks | .NET (Swashbuckle), Python (FastAPI built-in) |

Phase 1: Receive Context + Analyze API Structure

Accept Context Store and scan for API endpoints.

Required Context:

STACK: .NET or Python
PROJECT_ROOT: Project directory path

Idempotency Check:

.NET: Grep for AddSwaggerGen or UseSwagger
Python: FastAPI has built-in OpenAPI, check for custom configuration
If found: Return { "status": "skipped" }

API Analysis:

Scan for controller/router files
Identify authentication method (JWT, OAuth2, API Key)
Check for API versioning

Phase 2: Research Documentation Standards

Use MCP tools for current documentation.

For .NET:

MCP ref: "Swashbuckle ASP.NET Core OpenAPI Swagger configuration"
Context7: /domaindrivendev/Swashbuckle.AspNetCore

For Python:

MCP ref: "FastAPI OpenAPI documentation customization"
Context7: /tiangolo/fastapi

Key Patterns to Research:

OpenAPI 3.0/3.1 specification
Security scheme definitions
XML comments integration (.NET)
Response examples and schemas
API versioning documentation

Phase 3: Decision Points

Q1: API Information

| Field | Description | Required | |-------|-------------|----------| | Title | API name | ✓ Yes | | Version | API version (v1, v2) | ✓ Yes | | Description | Brief description | Optional | | Contact | Support contact | Optional | | License | API license | Optional |

Q2: Security Scheme

| Scheme | Use Case | OpenAPI Type | |--------|----------|--------------| | JWT Bearer (Recommended) | Token in Authorization header | http + bearer | | API Key | Key in header or query | apiKey | | OAuth2 | Full OAuth2 flow | oauth2 | | None | Public API | No security |

Q3: Documentation Features

| Feature | .NET | Python | Default | |---------|------|--------|---------| | XML Comments | ✓ Supported | N/A | ✓ Enable | | Response Examples | ✓ Manual | ✓ Pydantic | ✓ Enable | | Request Validation | ✓ Annotations | ✓ Pydantic | ✓ Enable | | Try It Out | ✓ Yes | ✓ Yes | ✓ Enable |

Phase 4: Generate Configuration

.NET Output Files

| File | Purpose | |------|---------| | Extensions/SwaggerExtensions.cs | Swagger service registration | | *.csproj (update) | Enable XML documentation |

Generation Process:

Use MCP ref for current Swashbuckle API
Generate SwaggerExtensions with:
- AddEndpointsApiExplorer
- AddSwaggerGen with OpenApiInfo
- Security definition (if auth detected)
- XML comments inclusion
Update csproj for documentation generation

Packages to Add:

Swashbuckle.AspNetCore

Registration Code:

builder.Services.AddSwaggerServices();
// ...
app.UseSwaggerServices();

csproj Update:

<PropertyGroup>
  <GenerateDocumentationFile>true</GenerateDocumentationFile>
  <NoWarn>$(NoWarn);1591</NoWarn>
</PropertyGroup>

Python Output Files

| File | Purpose | |------|---------| | core/openapi_config.py | OpenAPI customization |

Generation Process:

Use MCP ref for FastAPI OpenAPI customization
Generate openapi_config.py with:
- Custom OpenAPI schema
- Security scheme definitions
- Tags and descriptions
FastAPI generates OpenAPI automatically

Note: FastAPI has built-in OpenAPI support. This worker customizes the default configuration.

Registration Code:

from core.openapi_config import custom_openapi
app.openapi = lambda: custom_openapi(app)

Phase 5: Validate

Validation Steps:

Syntax check:
- .NET: dotnet build --no-restore
- Python: python -m py_compile core/openapi_config.py
Access documentation: | Stack | URL | |-------|-----| | .NET | http://localhost:5000/swagger | | Python | http://localhost:5000/docs | | Python (ReDoc) | http://localhost:5000/redoc |
Verify content:
- [ ] All endpoints visible
- [ ] Request/response schemas displayed
- [ ] Security scheme shown (if configured)
- [ ] Try It Out functional

OpenAPI spec validation:

# .NET
curl http://localhost:5000/swagger/v1/swagger.json | jq .

# Python
curl http://localhost:5000/openapi.json | jq .

Security Scheme Examples

JWT Bearer (.NET)

// Structure only - actual code generated via MCP ref
options.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme
{
    Description = "JWT Authorization header using Bearer scheme",
    Name = "Authorization",
    In = ParameterLocation.Header,
    Type = SecuritySchemeType.Http,
    Scheme = "bearer",
    BearerFormat = "JWT"
});

JWT Bearer (Python/FastAPI)

# Structure only - actual code generated via MCP ref
from fastapi.security import HTTPBearer
security = HTTPBearer()

Return to Coordinator

{
  "status": "success",
  "files_created": [
    "Extensions/SwaggerExtensions.cs"
  ],
  "packages_added": [
    "Swashbuckle.AspNetCore"
  ],
  "registration_code": "builder.Services.AddSwaggerServices();",
  "message": "Configured Swagger/OpenAPI documentation"
}

Reference Links

Critical Rules

Use MCP ref for current Swashbuckle/FastAPI API — do not hardcode configuration from memory
Auto-detect auth scheme — scan for JWT, OAuth2, or API Key and configure security definition accordingly
Enable XML documentation in .NET — update csproj with GenerateDocumentationFile and suppress warning 1591
FastAPI: customize, not replace — built-in OpenAPI works by default, only add custom schema/security
Idempotent — if AddSwaggerGen/UseSwagger exists, return status: "skipped"

Definition of Done

Context Store received (stack, project root)
API structure analyzed (controllers/routers, auth method, versioning)
Documentation standards researched via MCP tools
Swagger/OpenAPI configuration generated with API info and security scheme
XML comments enabled (.NET) or custom OpenAPI schema configured (Python)
Syntax validated (dotnet build or py_compile)
Structured JSON response returned to ln-770 coordinator

Version: 2.0.0 Last Updated: 2026-01-10

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