ln-775-api-docs-generator

name	ln-775-api-docs-generator
description	Configures Swagger/OpenAPI documentation for backend APIs. Use when adding interactive API docs to a project.
license	MIT

ln-775-api-docs-generator

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

Configures API documentation with Swagger/OpenAPI.

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Overview

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

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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:

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

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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:

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

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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

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Phase 4: Generate Configuration

.NET Output Files

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

Generation Process:

1. Use MCP ref for current Swashbuckle API
2. Generate SwaggerExtensions with:
   • AddEndpointsApiExplorer
   • AddSwaggerGen with OpenApiInfo
   • Security definition (if auth detected)
   • XML comments inclusion
3. 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:

1. Use MCP ref for FastAPI OpenAPI customization
2. Generate openapi_config.py with:
   • Custom OpenAPI schema
   • Security scheme definitions
   • Tags and descriptions
3. 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)

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Phase 5: Validate

Validation Steps:

1. Syntax check:

   • .NET: dotnet build --no-restore
   • Python: python -m py_compile core/openapi_config.py

2. Access documentation:

   Stack	URL
   .NET	http://localhost:5000/swagger
   Python	http://localhost:5000/docs
   Python (ReDoc)	http://localhost:5000/redoc

3. Verify content:

   • All endpoints visible
   • Request/response schemas displayed
   • Security scheme shown (if configured)
   • Try It Out functional

4. OpenAPI spec validation:

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

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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()

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Return to Coordinator

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

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Reference Links

• Swashbuckle.AspNetCore
• FastAPI OpenAPI
• OpenAPI Specification

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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

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Version: 2.0.0 Last Updated: 2026-01-10