README_DOCUMENTATION.md

📚 TeachLink API Documentation System

Automatic, comprehensive API documentation generation with multi-language support, versioning, and interactive browsing.

Quick Start

1. Generate Documentation

# Generate OpenAPI spec
npm run docs:generate

# Generate multi-language code examples
npm run docs:generate:examples

# Or do both at once
npm run docs:check

2. View Documentation

Option A: Interactive Runtime Docs

npm run start:dev
# Open http://localhost:3000/api/docs

Option B: Static Documentation Site

npm run docs:view
# Open http://localhost:8080

3. Archive Version (on Release)

npm run docs:version
# Creates docs/versions/v1.0.0/

Features

🚀 Automatic Generation

• ✅ OpenAPI/Swagger - Auto-generated from code
• ✅ Code Examples - 7 programming languages
• ✅ Interactive Docs - ReDoc viewer
• ✅ Version Tracking - Changelog and comparisons
• ✅ Schema Validation - Consistent responses

🌍 Multi-Language Examples

1. cURL - Command line testing
2. TypeScript - Modern async/await
3. Python - Requests library
4. JavaScript - Fetch API
5. Go - Native http
6. Java - HttpURLConnection
7. C# - HttpClient

📦 SDK Generation

• TypeScript/JavaScript SDK
• Python SDK
• Auto-generated from OpenAPI spec

📊 Version Management

• Archive documentation per release
• Compare API changes between versions
• Detect breaking changes
• Generate CHANGELOG automatically

Usage

For Developers

Update Documentation

After modifying an API endpoint:

npm run docs:generate
npm run docs:generate:examples

View Changes

# See what changed
git diff openapi-spec.json

# Compare API versions
npm run docs:versions:diff v1.0 v1.1

Test Documentation

# Validate OpenAPI spec
npm run docs:check

Use SDK in Code

TypeScript:

import { SearchApi } from './sdk/typescript';

const api = new SearchApi();
const courses = await api.searchContent('javascript');

Python:

from openapi_client.apis.tags import search_api

api = search_api.SearchApi()
courses = api.search_content(q='javascript')

For API Documentation Contributors

See API_DOCUMENTATION_BEST_PRACTICES.md for:

• How to document endpoints
• Swagger decorator examples
• Error response patterns
• Authentication documentation
• Testing documentation

For Release Process

# Before release
npm run docs:check          # Verify docs are current

# On release
npm run docs:version        # Archive documentation
git add docs/versions/
git commit -m "docs: archive API v1.0.0"
git push

Generated Files

docs/
├── api/                        # Generated API reference
│   ├── openapi-spec.json      # OpenAPI 3.0 spec
│   └── examples.md            # cURL examples
├── site/                       # Interactive documentation site
│   ├── index.html             # ReDoc viewer
│   ├── openapi-spec.json      # Spec for viewer
│   └── styles.css             # Styling
├── examples/                   # Multi-language code examples
│   ├── README.md              # Examples index
│   ├── 1_login.ts
│   ├── 1_login.py
│   ├── 1_login.js
│   ├── 1_login.go
│   ├── 1_login.java
│   ├── 1_login.cs
│   ├── 2_register.ts
│   └── ... (one set per endpoint)
├── versions/                   # Version archive
│   ├── VERSIONS.md            # Version index
│   ├── CHANGELOG.md           # API changelog
│   ├── v1.0.0/
│   │   ├── openapi-spec.json
│   │   ├── examples/
│   │   └── metadata.json
│   └── v1.1.0/
│       └── ...
└── *.md                        # This guide & best practices

openapi-spec.json              # Root OpenAPI spec
sdk/
├── typescript/                # Generated TypeScript SDK
└── python/                    # Generated Python SDK

All Available Commands

# Generation
npm run docs:generate          # Generate OpenAPI spec from code
npm run docs:generate:examples # Generate examples in 7 languages
npm run docs:check            # Generate everything + validate

# Viewing
npm run docs:view             # Serve docs locally on port 8080

# Versioning
npm run docs:version          # Archive current docs as version
npm run docs:versions:list    # List all archived versions
npm run docs:versions:compare # Compare two versions
npm run docs:versions:diff    # Show detailed endpoint changes

# SDK Generation
npm run sdk:generate          # Generate all SDKs (TS, Python)
npm run sdk:generate:ts       # TypeScript SDK only
npm run sdk:generate:python   # Python SDK only
npm run sdk:generate:spec     # Refresh spec for SDKs

Directory Structure

OpenAPI Spec Locations

• openapi-spec.json - Root spec (primary)
• docs/api/openapi-spec.json - API docs copy
• docs/site/openapi-spec.json - Site viewer copy
• docs/versions/v1.0.0/openapi-spec.json - Version archive

Example Code

• docs/examples/README.md - Examples index
• docs/examples/1_login.ts - TypeScript example
• docs/examples/1_login.py - Python example
• docs/examples/1_login.js - JavaScript example
• docs/examples/1_login.go - Go example
• docs/examples/1_login.java - Java example
• docs/examples/1_login.cs - C# example

Documentation Versions

• docs/versions/VERSIONS.md - Version index
• docs/versions/CHANGELOG.md - API changelog
• docs/versions/v1.0.0/openapi-spec.json - Versioned spec
• docs/versions/v1.0.0/examples/ - Versioned examples

Documentation Workflow

For Each Commit

1. Auto-run (if CI/CD configured)

   npm run docs:generate
   npm run docs:generate:examples

2. Changes auto-committed

   • openapi-spec.json
   • docs/site/
   • docs/api/
   • docs/examples/

For Each Release

1. Archive version

   npm run docs:version

2. Commit version

   git add docs/versions/
   git commit -m "docs: archive API v1.0.0"

3. View changelog

   npm run docs:versions:list

For Breaking Changes

1. Compare versions

   npm run docs:versions:diff v1.0 v2.0

2. Check changelog

   cat docs/versions/CHANGELOG.md

Interactive Documentation

Runtime Swagger UI

npm run start:dev
# Open http://localhost:3000/api/docs

Features:

• "Try it out" button for testing
• Request/response examples
• Parameter validation
• Bearer token authentication
• Real-time API testing

Static ReDoc Site

npm run docs:view
# Open http://localhost:8080

Features:

• Beautiful, interactive documentation
• Sidebar navigation
• Search across endpoints
• Code samples in multiple languages
• No external dependencies

API Endpoints Structure

All endpoints documented with:

GET /courses
├── Summary: List courses
├── Description: Retrieve paginated list of courses
├── Parameters: page, limit, category
├── Request Body: (none)
├── Response (200): Courses found
├── Response (400): Invalid parameters
├── Auth: Optional
└── Examples:
    ├── cURL
    ├── TypeScript
    ├── Python
    ├── JavaScript
    ├── Go
    ├── Java
    └── C#

Version Management

Track Changes

# View all versions
npm run docs:versions:list

# Compare two versions
npm run docs:versions:compare v1.0 v1.1

# Show detailed changes
npm run docs:versions:diff v1.0 v1.1

Output includes:

• ✅ Added endpoints
• ❌ Removed endpoints (breaking)
• 🔄 Modified endpoints
• Parameter changes
• Response changes

Generate Changelog

Changelog is auto-generated in docs/versions/CHANGELOG.md:

## v2.0.0
### ✅ Added
- POST /courses/publish

### ❌ Breaking Changes
- Removed: DELETE /courses/{id}

### 🔄 Modified
- GET /courses (added pagination)

Validation & Testing

Verify Documentation is Current

npm run docs:check

This will:

1. Generate OpenAPI spec
2. Generate examples
3. Validate OpenAPI spec format
4. Compare with git for changes

Test Documentation in CI/CD

The system includes validation for:

• Valid OpenAPI 3.0 spec
• Required endpoints documented
• Consistent error responses
• Authentication requirements

Configuration

Environment Variables

Optional in .env:

API_VERSION=1.0.0
API_TITLE=TeachLink API
API_DESCRIPTION=Learning platform API

OpenAPI Server Configuration

Configured in scripts/generate-api-docs.js:

servers: [
  { url: 'http://localhost:3000', description: 'Local development' },
  { url: 'https://api.staging.teachlink.com', description: 'Staging' },
  { url: 'https://api.teachlink.com', description: 'Production' },
]

Security Schemes

Configured in spec:

bearerAuth: HTTP Bearer (JWT)
apiKeyAuth: Optional API key

Troubleshooting

Docs not updating after code changes

npm run docs:generate
npm run docs:generate:examples
ls -la docs/  # Check timestamps

OpenAPI spec validation fails

npm install -g swagger-cli
swagger-cli validate openapi-spec.json

ReDoc site not loading

# Check file exists
test -f docs/site/index.html && echo "✅ File exists"

# Check permissions
ls -la docs/site/

# Serve locally
npm run docs:view

Examples not generating

npm run docs:generate:examples
ls -la docs/examples/

SDK generation fails

# Validate spec first
swagger-cli validate openapi-spec.json

# Try generate with verbose
npm run sdk:generate -- --verbose

Best Practices

✅ Do:

• Run npm run docs:check before committing
• Use @ApiTags and @ApiOperation in controllers
• Document all response codes
• Include examples in decorators
• Archive versions on release
• Keep docs in git

❌ Don't:

• Manually edit generated files
• Forget to update examples
• Skip error response documentation
• Leave controllers without tags
• Generate docs without testing

Integration with CI/CD

To auto-generate and publish docs on every commit:

1. Create .github/workflows/api-docs.yml (template provided in implementation)
2. Configure GitHub Pages or CDN
3. Add Slack notifications (optional)

Benefits:

• Automatic doc generation
• Version archival on release
• GitHub Pages publishing
• Change notifications
• Breaking change detection

Publishing Documentation

GitHub Pages

# Docs published to: https://yourusername.github.io/teachLink_backend/

Custom Domain

# docs/site/ deployed to your domain
# Example: https://api-docs.teachlink.com

CDN (S3 + CloudFront)

aws s3 sync docs/site/ s3://your-bucket/

Support & Resources

• Guide: API_DOCUMENTATION_GUIDE.md
• Best Practices: API_DOCUMENTATION_BEST_PRACTICES.md
• Implementation Details: IMPLEMENTATION_SUMMARY.md
• OpenAPI Spec: openapi-spec.json
• Official Docs: https://docs.nestjs.com/openapi/introduction

Next Steps

1. ✅ Run npm run docs:generate to generate initial docs
2. ✅ Run npm run docs:view to preview
3. ✅ Review generated files in docs/
4. ✅ Add decorators to controllers for better docs (optional)
5. ✅ Set up CI/CD for automation (optional)
6. ✅ Archive first version: npm run docs:version

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Questions? Check the troubleshooting section or review the detailed guides linked above.