Generate comprehensive OpenAPI/Swagger documentation from existing APIs
Scanned 6/1/2026
Install via CLI
Skills Directoryopenskills install tools-only/X-Skills---
name: generate-api-docs
description: >
Generate comprehensive OpenAPI/Swagger documentation from existing APIs
shortcut: apid
---
# Generate API Documentation
Automatically generate comprehensive OpenAPI 3.0 specifications with interactive documentation, automated testing, and multi-language client SDKs from your existing API codebase or by analyzing live endpoints.
## When to Use This Command
Use `/generate-api-docs` when you need to:
- Document existing APIs without manual specification writing
- Generate interactive API documentation for developers
- Create Postman/Insomnia collections from your API
- Enable "try it out" functionality for API endpoints
- Generate client SDKs in multiple languages
- Maintain API documentation synchronized with code
- Create API reference documentation for external consumers
- Validate API contracts and schemas
- Enable API mocking for frontend development
DON'T use this when:
- Your API is still in early design phase (use `/api-contract-generator` instead)
- You only need internal code comments (use JSDoc/docstrings)
- Building GraphQL APIs (use `/build-graphql-server` with introspection)
- APIs have no stable contract (too early in development)
## Design Decisions
This command implements **OpenAPI 3.0.3 specification** as the primary approach because:
- Industry standard adopted by major organizations
- Extensive tooling ecosystem (Swagger UI, Redoc, SDKs)
- Supports complex schemas including oneOf, allOf, discriminators
- Native support for webhooks and callbacks
- JSON Schema validation built-in
- Multiple security schemes support
**Alternative considered: API Blueprint**
- Markdown-based format
- Simpler for human writing
- Less tooling support
- Recommended for documentation-first design
**Alternative considered: RAML**
- YAML-based with reusable components
- Good for large enterprise APIs
- Smaller ecosystem
- Recommended when modularity is critical
**Alternative considered: AsyncAPI**
- Specialized for event-driven APIs
- WebSocket and message queue support
- Use alongside OpenAPI for complete coverage
## Prerequisites
Before running this command:
1. Functioning API with consistent patterns
2. Request/response examples available
3. Authentication mechanism implemented
4. Error response format standardized
5. API versioning strategy defined
## Implementation Process
### Step 1: API Analysis and Discovery
Scan codebase and running API to discover all endpoints, methods, and data structures.
### Step 2: Schema Extraction
Extract request/response schemas from code annotations, TypeScript types, or runtime analysis.
### Step 3: OpenAPI Generation
Generate complete OpenAPI 3.0 specification with all paths, schemas, and security definitions.
### Step 4: Documentation Enhancement
Add descriptions, examples, and grouping tags for better organization and understanding.
### Step 5: Interactive Documentation Setup
Deploy Swagger UI and Redoc for interactive API exploration and testing.
## Output Format
The command generates:
- `openapi.yaml` - Main OpenAPI 3.0 specification
- `openapi.json` - JSON format for tooling
- `docs/` - Static HTML documentation
- `index.html` - Swagger UI interface
- `redoc.html` - Redoc documentation
- `collections/` - External tool formats
- `postman_collection.json` - Postman import
- `insomnia_workspace.json` - Insomnia import
- `bruno_collection.bru` - Bruno collection
- `examples/` - Request/response examples
- `schemas/` - Extracted JSON schemas
- `README.md` - Getting started guide
## Code Examples
### Example 1: Express.js API with Automatic Documentation Generation
```javascript
// api-documentation-generator.js
const swaggerJsdoc = require('swagger-jsdoc');
const swaggerUi = require('swagger-ui-express');
const { z } = require('zod');
const zodToJsonSchema = require('zod-to-json-schema');
const express = require('express');
const fs = require('fs').promises;
const path = require('path');
const yaml = require('js-yaml');
class APIDocumentationGenerator {
constructor(app, config = {}) {
this.app = app;
this.config = {
title: config.title || 'API Documentation',
version: config.version || '1.0.0',
description: config.description || 'API Documentation',
servers: config.servers || [{ url: 'http://localhost:3000' }],
contact: config.contact || {},
license: config.license || { name: 'MIT' },
security: config.security || [],
...config
};
this.paths = {};
this.schemas = {};
this.examples = {};
this.tags = [];
}
// Analyze Express routes and generate OpenAPI paths
analyzeRoutes() {
const routes = [];
// Extract all routes from Express app
this.app._router.stack.forEach((middleware) => {
if (middleware.route) {
// Regular routes
routes.push({
path: middleware.route.path,
methods: Object.keys(middleware.route.methods)
});
} else if (middleware.name === 'router') {
// Router middleware
middleware.handle.stack.forEach((handler) => {
if (handler.route) {
const basePath = middleware.regexp.source
.replace('\\/?', '')
.replace('(?=\\/|$)', '')
.replace(/\\/g, '/')
.replace('^', '');
routes.push({
path: basePath + handler.route.path,
methods: Object.keys(handler.route.methods)
});
}
});
}
});
// Convert Express routes to OpenAPI paths
routes.forEach(route => {
const openApiPath = this.expressToOpenAPIPath(route.path);
if (!this.paths[openApiPath]) {
this.paths[openApiPath] = {};
}
route.methods.forEach(method => {
this.paths[openApiPath][method] = this.generateOperation(
method,
route.path,
openApiPath
);
});
});
return this.paths;
}
// Convert Express path to OpenAPI format
expressToOpenAPIPath(expressPath) {
// Convert :param to {param}
return expressPath.replace(/:([^/]+)/g, '{$1}');
}
// Generate operation object for a route
generateOperation(method, expressPath, openApiPath) {
const operation = {
tags: this.inferTags(expressPath),
summary: this.generateSummary(method, expressPath),
description: this.generateDescription(method, expressPath),
operationId: this.generateOperationId(method, expressPath),
parameters: this.extractParameters(openApiPath),
responses: this.generateResponses(method, expressPath)
};
// Add request body for POST, PUT, PATCH
if (['post', 'put', 'patch'].includes(method)) {
operation.requestBody = this.generateRequestBody(method, expressPath);
}
// Add security if applicable
if (this.requiresAuth(expressPath)) {
operation.security = [{ bearerAuth: [] }];
}
return operation;
}
// Infer tags from path
inferTags(path) {
const segments = path.split('/').filter(s => s && !s.startsWith(':'));
if (segments.length > 0) {
const tag = segments[0].charAt(0).toUpperCase() + segments[0].slice(1);
// Add tag to tags list if not exists
if (!this.tags.find(t => t.name === tag)) {
this.tags.push({
name: tag,
description: `Operations related to ${tag.toLowerCase()}`
});
}
return [tag];
}
return ['General'];
}
// Generate operation summary
generateSummary(method, path) {
const resource = path.split('/').filter(s => s && !s.startsWith(':')).pop() || 'resource';
const summaries = {
get: path.includes(':') ? `Get ${resource} by ID` : `List all ${resource}`,
post: `Create a new ${resource}`,
put: `Update ${resource}`,
patch: `Partially update ${resource}`,
delete: `Delete ${resource}`,
head: `Check ${resource} existence`,
options: `Get ${resource} options`
};
return summaries[method] || `${method.toUpperCase()} ${resource}`;
}
// Generate detailed description
generateDescription(method, path) {
const resource = path.split('/').filter(s => s && !s.startsWith(':')).pop() || 'resource';
return `Performs a ${method.toUpperCase()} operation on ${resource}. ` +
`This endpoint ${this.requiresAuth(path) ? 'requires authentication' : 'is publicly accessible'}.`;
}
// Generate operation ID
generateOperationId(method, path) {
const segments = path.split('/').filter(s => s && !s.startsWith(':'));
const resource = segments.join('_');
return `${method}_${resource}`.replace(/[^a-zA-Z0-9_]/g, '_');
}
// Extract parameters from path
extractParameters(path) {
const parameters = [];
// Extract path parameters
const pathParams = path.match(/{([^}]+)}/g);
if (pathParams) {
pathParams.forEach(param => {
const name = param.slice(1, -1);
parameters.push({
name,
in: 'path',
required: true,
description: `ID of the ${name}`,
schema: {
type: 'string',
format: name.toLowerCase().includes('id') ? 'uuid' : undefined
}
});
});
}
// Add common query parameters for list operations
if (!path.includes('{')) {
parameters.push(
{
name: 'page',
in: 'query',
description: 'Page number for pagination',
schema: { type: 'integer', default: 1, minimum: 1 }
},
{
name: 'limit',
in: 'query',
description: 'Number of items per page',
schema: { type: 'integer', default: 20, minimum: 1, maximum: 100 }
},
{
name: 'sort',
in: 'query',
description: 'Sort field and direction (e.g., "name:asc")',
schema: { type: 'string' }
},
{
name: 'filter',
in: 'query',
description: 'Filter criteria',
schema: { type: 'string' }
}
);
}
return parameters;
}
// Generate request body schema
generateRequestBody(method, path) {
const resource = path.split('/').filter(s => s && !s.startsWith(':')).pop() || 'resource';
const schemaName = resource.charAt(0).toUpperCase() + resource.slice(1);
// Generate or retrieve schema
if (!this.schemas[schemaName]) {
this.schemas[schemaName] = this.generateResourceSchema(schemaName);
}
return {
required: method === 'post',
content: {
'application/json': {
schema: {
$ref: `#/components/schemas/${schemaName}`
},
examples: this.generateExamples(schemaName)
}
}
};
}
// Generate resource schema
generateResourceSchema(name) {
// This would ideally extract from your actual models
// Here's a generic example
return {
type: 'object',
required: ['name'],
properties: {
id: {
type: 'string',
format: 'uuid',
readOnly: true,
description: 'Unique identifier'
},
name: {
type: 'string',
minLength: 1,
maxLength: 255,
description: `Name of the ${name.toLowerCase()}`
},
description: {
type: 'string',
maxLength: 1000,
description: 'Detailed description'
},
status: {
type: 'string',
enum: ['active', 'inactive', 'pending'],
default: 'active',
description: 'Current status'
},
metadata: {
type: 'object',
additionalProperties: true,
description: 'Additional metadata'
},
createdAt: {
type: 'string',
format: 'date-time',
readOnly: true,
description: 'Creation timestamp'
},
updatedAt: {
type: 'string',
format: 'date-time',
readOnly: true,
description: 'Last update timestamp'
}
}
};
}
// Generate response schemas
generateResponses(method, path) {
const responses = {
'200': {
description: 'Successful operation',
content: {
'application/json': {
schema: this.generateResponseSchema(method, path)
}
}
},
'400': {
description: 'Bad request',
content: {
'application/json': {
schema: { $ref: '#/components/schemas/Error' }
}
}
},
'401': {
description: 'Unauthorized',
content: {
'application/json': {
schema: { $ref: '#/components/schemas/Error' }
}
}
},
'404': {
description: 'Resource not found',
content: {
'application/json': {
schema: { $ref: '#/components/schemas/Error' }
}
}
},
'500': {
description: 'Internal server error',
content: {
'application/json': {
schema: { $ref: '#/components/schemas/Error' }
}
}
}
};
// Customize based on method
if (method === 'post') {
responses['201'] = responses['200'];
responses['201'].description = 'Resource created successfully';
delete responses['200'];
} else if (method === 'delete') {
responses['204'] = {
description: 'Resource deleted successfully'
};
delete responses['200'];
}
return responses;
}
// Generate response schema based on operation
generateResponseSchema(method, path) {
const resource = path.split('/').filter(s => s && !s.startsWith(':')).pop() || 'resource';
const schemaName = resource.charAt(0).toUpperCase() + resource.slice(1);
if (!path.includes(':') && method === 'get') {
// List operation
return {
type: 'object',
properties: {
data: {
type: 'array',
items: { $ref: `#/components/schemas/${schemaName}` }
},
pagination: { $ref: '#/components/schemas/Pagination' },
meta: { $ref: '#/components/schemas/Meta' }
}
};
} else {
// Single resource
return { $ref: `#/components/schemas/${schemaName}` };
}
}
// Generate examples for schemas
generateExamples(schemaName) {
return {
default: {
summary: 'Standard example',
value: {
name: `Example ${schemaName}`,
description: 'This is an example description',
status: 'active',
metadata: {
category: 'example',
priority: 'high'
}
}
},
minimal: {
summary: 'Minimal required fields',
value: {
name: `Minimal ${schemaName}`
}
},
complete: {
summary: 'All fields populated',
value: {
id: '550e8400-e29b-41d4-a716-446655440000',
name: `Complete ${schemaName}`,
description: 'This example includes all possible fields',
status: 'active',
metadata: {
category: 'complete',
priority: 'high',
tags: ['example', 'complete'],
customField: 'custom value'
},
createdAt: '2024-01-15T10:30:00Z',
updatedAt: '2024-01-15T14:45:00Z'
}
}
};
}
// Check if path requires authentication
requiresAuth(path) {
// Implement your auth logic
const publicPaths = ['/health', '/docs', '/api-docs', '/login', '/register'];
return !publicPaths.some(p => path.includes(p));
}
// Add common schemas
addCommonSchemas() {
this.schemas.Error = {
type: 'object',
required: ['code', 'message'],
properties: {
code: {
type: 'string',
description: 'Error code'
},
message: {
type: 'string',
description: 'Error message'
},
details: {
type: 'object',
additionalProperties: true,
description: 'Additional error details'
},
timestamp: {
type: 'string',
format: 'date-time',
description: 'Error timestamp'
}
}
};
this.schemas.Pagination = {
type: 'object',
properties: {
page: { type: 'integer', minimum: 1 },
limit: { type: 'integer', minimum: 1, maximum: 100 },
total: { type: 'integer', minimum: 0 },
pages: { type: 'integer', minimum: 0 }
}
};
this.schemas.Meta = {
type: 'object',
properties: {
version: { type: 'string' },
timestamp: { type: 'string', format: 'date-time' },
requestId: { type: 'string', format: 'uuid' }
}
};
}
// Generate complete OpenAPI specification
generateOpenAPISpec() {
// Analyze routes
this.analyzeRoutes();
// Add common schemas
this.addCommonSchemas();
const spec = {
openapi: '3.0.3',
info: {
title: this.config.title,
version: this.config.version,
description: this.config.description,
contact: this.config.contact,
license: this.config.license
},
servers: this.config.servers,
tags: this.tags,
paths: this.paths,
components: {
schemas: this.schemas,
securitySchemes: {
bearerAuth: {
type: 'http',
scheme: 'bearer',
bearerFormat: 'JWT'
},
apiKey: {
type: 'apiKey',
name: 'X-API-Key',
in: 'header'
},
oauth2: {
type: 'oauth2',
flows: {
authorizationCode: {
authorizationUrl: 'https://auth.example.com/oauth/authorize',
tokenUrl: 'https://auth.example.com/oauth/token',
refreshUrl: 'https://auth.example.com/oauth/refresh',
scopes: {
read: 'Read access',
write: 'Write access',
admin: 'Admin access'
}
}
}
}
}
},
security: this.config.security
};
return spec;
}
// Export to various formats
async exportDocumentation(outputDir = './api-docs') {
const spec = this.generateOpenAPISpec();
// Create output directory
await fs.mkdir(outputDir, { recursive: true });
await fs.mkdir(path.join(outputDir, 'collections'), { recursive: true });
// Save OpenAPI spec in YAML and JSON
await fs.writeFile(
path.join(outputDir, 'openapi.yaml'),
yaml.dump(spec, { indent: 2 })
);
await fs.writeFile(
path.join(outputDir, 'openapi.json'),
JSON.stringify(spec, null, 2)
);
// Generate Postman collection
const postmanCollection = this.convertToPostmanCollection(spec);
await fs.writeFile(
path.join(outputDir, 'collections', 'postman_collection.json'),
JSON.stringify(postmanCollection, null, 2)
);
// Generate HTML documentation
await this.generateHTMLDocs(spec, outputDir);
// Generate README
await this.generateREADME(spec, outputDir);
console.log(`API documentation generated in ${outputDir}`);
return spec;
}
// Convert OpenAPI to Postman Collection
convertToPostmanCollection(openApiSpec) {
const collection = {
info: {
name: openApiSpec.info.title,
description: openApiSpec.info.description,
version: openApiSpec.info.version,
schema: 'https://schema.getpostman.com/json/collection/v2.1.0/collection.json'
},
item: [],
auth: {
type: 'bearer',
bearer: [{
key: 'token',
value: '{{access_token}}',
type: 'string'
}]
},
variable: [
{
key: 'baseUrl',
value: openApiSpec.servers[0].url,
type: 'string'
},
{
key: 'access_token',
value: '',
type: 'string'
}
]
};
// Group by tags
const folders = {};
Object.entries(openApiSpec.paths).forEach(([path, methods]) => {
Object.entries(methods).forEach(([method, operation]) => {
const tag = operation.tags?.[0] || 'General';
if (!folders[tag]) {
folders[tag] = {
name: tag,
item: []
};
}
const request = {
name: operation.summary,
request: {
method: method.toUpperCase(),
header: [],
url: {
raw: `{{baseUrl}}${path}`,
host: ['{{baseUrl}}'],
path: path.split('/').filter(p => p)
},
description: operation.description
}
};
// Add path parameters
if (operation.parameters) {
const pathParams = operation.parameters.filter(p => p.in === 'path');
const queryParams = operation.parameters.filter(p => p.in === 'query');
if (pathParams.length > 0) {
request.request.url.variable = pathParams.map(p => ({
key: p.name,
value: '',
description: p.description
}));
}
if (queryParams.length > 0) {
request.request.url.query = queryParams.map(p => ({
key: p.name,
value: '',
description: p.description,
disabled: !p.required
}));
}
}
// Add request body
if (operation.requestBody) {
const content = operation.requestBody.content['application/json'];
if (content) {
request.request.header.push({
key: 'Content-Type',
value: 'application/json'
});
request.request.body = {
mode: 'raw',
raw: JSON.stringify(
content.examples?.default?.value || {},
null,
2
)
};
}
}
// Add auth if required
if (operation.security) {
request.request.auth = {
type: 'bearer',
bearer: [{
key: 'token',
value: '{{access_token}}'
}]
};
}
folders[tag].item.push(request);
});
});
collection.item = Object.values(folders);
return collection;
}
// Generate HTML documentation
async generateHTMLDocs(spec, outputDir) {
// Swagger UI HTML
const swaggerHtml = `
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>${spec.info.title} - Swagger UI</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/swagger-ui-dist@5.9.0/swagger-ui.css">
<style>
body { margin: 0; padding: 0; }
.swagger-ui .topbar { display: none; }
</style>
</head>
<body>
<div id="swagger-ui"></div>
<script src="https://cdn.jsdelivr.net/npm/swagger-ui-dist@5.9.0/swagger-ui-bundle.js"></script>
<script src="https://cdn.jsdelivr.net/npm/swagger-ui-dist@5.9.0/swagger-ui-standalone-preset.js"></script>
<script>
window.onload = () => {
window.ui = SwaggerUIBundle({
url: './openapi.json',
dom_id: '#swagger-ui',
presets: [
SwaggerUIBundle.presets.apis,
SwaggerUIStandalonePreset
],
layout: "BaseLayout",
deepLinking: true,
showExtensions: true,
showCommonExtensions: true,
tryItOutEnabled: true
});
};
</script>
</body>
</html>`;
// Redoc HTML
const redocHtml = `
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>${spec.info.title} - ReDoc</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
body { margin: 0; padding: 0; }
</style>
</head>
<body>
<redoc spec-url='./openapi.json'></redoc>
<script src="https://cdn.jsdelivr.net/npm/redoc@2.0.0/bundles/redoc.standalone.js"></script>
</body>
</html>`;
await fs.writeFile(path.join(outputDir, 'index.html'), swaggerHtml);
await fs.writeFile(path.join(outputDir, 'redoc.html'), redocHtml);
}
// Generate README documentation
async generateREADME(spec, outputDir) {
const readme = `# ${spec.info.title}
${spec.info.description}
**Version:** ${spec.info.version}
## Base URL
\`\`\`
${spec.servers.map(s => s.url).join('\n')}
\`\`\`
## Authentication
This API uses the following authentication methods:
${spec.components.securitySchemes ? Object.entries(spec.components.securitySchemes).map(([name, scheme]) =>
`- **${name}**: ${scheme.type} ${scheme.scheme || ''}`
).join('\n') : '- No authentication required'}
## Available Endpoints
${Object.entries(spec.paths).map(([path, methods]) =>
Object.entries(methods).map(([method, op]) =>
`- \`${method.toUpperCase()} ${path}\` - ${op.summary}`
).join('\n')
).join('\n')}
## Quick Start
### Installation
\`\`\`bash
# Using npm
npm install axios
# Using curl
curl -X GET "${spec.servers[0].url}/endpoint"
\`\`\`
### Example Request
\`\`\`javascript
const axios = require('axios');
const config = {
method: 'get',
url: '${spec.servers[0].url}${Object.keys(spec.paths)[0]}',
headers: {
'Authorization': 'Bearer YOUR_ACCESS_TOKEN'
}
};
axios(config)
.then(response => {
console.log(JSON.stringify(response.data));
})
.catch(error => {
console.error(error);
});
\`\`\`
## Documentation
- [Swagger UI](./index.html) - Interactive API documentation
- [ReDoc](./redoc.html) - Alternative documentation format
- [OpenAPI Spec](./openapi.json) - Raw OpenAPI specification
- [Postman Collection](./collections/postman_collection.json) - Import to Postman
## SDKs
Generate client SDKs using:
\`\`\`bash
# JavaScript/TypeScript
npx @openapitools/openapi-generator-cli generate -i openapi.yaml -g typescript-axios -o ./sdk/typescript
# Python
openapi-generator-cli generate -i openapi.yaml -g python -o ./sdk/python
# Go
openapi-generator-cli generate -i openapi.yaml -g go -o ./sdk/go
\`\`\`
## Support
${spec.info.contact?.email ? `For support, contact ${spec.info.contact.email}` : 'For support, please refer to the documentation.'}
## License
${spec.info.license?.name || 'See LICENSE file'}
`;
await fs.writeFile(path.join(outputDir, 'README.md'), readme);
}
// Setup interactive documentation routes
setupDocumentationRoutes(basePath = '/api-docs') {
// Serve OpenAPI spec
this.app.get(`${basePath}/openapi.json`, (req, res) => {
res.json(this.generateOpenAPISpec());
});
// Serve Swagger UI
this.app.use(
`${basePath}`,
swaggerUi.serve,
swaggerUi.setup(this.generateOpenAPISpec(), {
customCss: '.swagger-ui .topbar { display: none }',
customSiteTitle: this.config.title
})
);
console.log(`API documentation available at ${basePath}`);
}
}
// Usage example
const app = express();
const docGenerator = new APIDocumentationGenerator(app, {
title: 'E-commerce API',
version: '2.0.0',
description: 'Complete e-commerce platform API with user management, products, and orders',
servers: [
{ url: 'https://api.example.com/v2', description: 'Production' },
{ url: 'https://staging-api.example.com/v2', description: 'Staging' },
{ url: 'http://localhost:3000', description: 'Development' }
],
contact: {
name: 'API Support',
email: 'api@example.com',
url: 'https://support.example.com'
}
});
// Generate and export documentation
docGenerator.exportDocumentation('./api-documentation');
// Setup interactive docs
docGenerator.setupDocumentationRoutes('/docs');
module.exports = APIDocumentationGenerator;
```
### Example 2: Python FastAPI with Automatic OpenAPI Enhancement
```python
# api_doc_enhancer.py
from fastapi import FastAPI, APIRouter, Depends, HTTPException
from fastapi.openapi.utils import get_openapi
from fastapi.openapi.docs import get_swagger_ui_html, get_redoc_html
from pydantic import BaseModel, Field
from typing import List, Optional, Dict, Any
import json
import yaml
from pathlib import Path
import httpx
from datetime import datetime
class OpenAPIEnhancer:
"""Enhance FastAPI's auto-generated OpenAPI with additional features"""
def __init__(self, app: FastAPI):
self.app = app
self.examples = {}
self.additional_schemas = {}
self.external_docs = {}
def enhance_openapi(self):
"""Enhance the OpenAPI spec with additional information"""
if self.app.openapi_schema:
return self.app.openapi_schema
openapi_schema = get_openapi(
title=self.app.title,
version=self.app.version,
description=self.app.description,
routes=self.app.routes,
)
# Add custom enhancements
self._add_api_versioning(openapi_schema)
self._add_rate_limiting_info(openapi_schema)
self._add_webhook_definitions(openapi_schema)
self._add_code_samples(openapi_schema)
self._add_security_schemes(openapi_schema)
self._add_server_variables(openapi_schema)
self._enhance_schemas(openapi_schema)
self._add_tags_metadata(openapi_schema)
self.app.openapi_schema = openapi_schema
return self.app.openapi_schema
def _add_api_versioning(self, spec: Dict[str, Any]):
"""Add API versioning information"""
spec["info"]["x-api-versioning"] = {
"strategy": "uri",
"current": "v2",
"supported": ["v1", "v2"],
"deprecated": ["v0"],
"sunset": {
"v0": "2024-01-01",
"v1": "2025-01-01"
}
}
def _add_rate_limiting_info(self, spec: Dict[str, Any]):
"""Add rate limiting documentation"""
spec["info"]["x-rate-limiting"] = {
"default": {
"requests": 1000,
"window": "1h"
},
"authenticated": {
"requests": 5000,
"window": "1h"
},
"endpoints": {
"/api/search": {
"requests": 100,
"window": "1m"
}
},
"headers": {
"limit": "X-RateLimit-Limit",
"remaining": "X-RateLimit-Remaining",
"reset": "X-RateLimit-Reset"
}
}
def _add_webhook_definitions(self, spec: Dict[str, Any]):
"""Add webhook definitions to OpenAPI spec"""
spec["webhooks"] = {
"orderCreated": {
"post": {
"requestBody": {
"description": "Order creation notification",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/OrderWebhook"
}
}
}
},
"responses": {
"200": {
"description": "Webhook processed successfully"
}
}
}
},
"paymentProcessed": {
"post": {
"requestBody": {
"description": "Payment processing notification",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/PaymentWebhook"
}
}
}
},
"responses": {
"200": {
"description": "Webhook acknowledged"
}
}
}
}
}
# Add webhook schemas
if "components" not in spec:
spec["components"] = {}
if "schemas" not in spec["components"]:
spec["components"]["schemas"] = {}
spec["components"]["schemas"]["OrderWebhook"] = {
"type": "object",
"required": ["event", "data", "timestamp"],
"properties": {
"event": {
"type": "string",
"enum": ["order.created", "order.updated", "order.cancelled"]
},
"data": {
"type": "object",
"properties": {
"orderId": {"type": "string", "format": "uuid"},
"customerId": {"type": "string", "format": "uuid"},
"amount": {"type": "number", "format": "float"},
"status": {"type": "string"}
}
},
"timestamp": {
"type": "string",
"format": "date-time"
}
}
}
def _add_code_samples(self, spec: Dict[str, Any]):
"""Add code samples to each endpoint"""
for path, methods in spec.get("paths", {}).items():
for method, operation in methods.items():
if method in ["get", "post", "put", "delete", "patch"]:
operation["x-code-samples"] = self._generate_code_samples(
method, path, operation
)
def _generate_code_samples(self, method: str, path: str, operation: Dict) -> List[Dict]:
"""Generate code samples for multiple languages"""
samples = []
# cURL example
curl_sample = f"curl -X {method.upper()} '{self.app.servers[0]['url'] if hasattr(self.app, 'servers') else 'https://api.example.com'}{path}'"
if method in ["post", "put", "patch"]:
curl_sample += """ \\
-H 'Content-Type: application/json' \\
-H 'Authorization: Bearer YOUR_TOKEN' \\
-d '{
"name": "example",
"value": 123
}'"""
else:
curl_sample += " \\\n -H 'Authorization: Bearer YOUR_TOKEN'"
samples.append({
"lang": "Shell",
"source": curl_sample,
"label": "cURL"
})
# Python example
python_sample = f"""import requests
url = "https://api.example.com{path}"
headers = {{
"Authorization": "Bearer YOUR_TOKEN",
"Content-Type": "application/json"
}}"""
if method in ["post", "put", "patch"]:
python_sample += """
data = {
"name": "example",
"value": 123
}
response = requests.""" + method + """(url, json=data, headers=headers)"""
else:
python_sample += f"""
response = requests.{method}(url, headers=headers)"""
python_sample += """
print(response.json())"""
samples.append({
"lang": "Python",
"source": python_sample,
"label": "Python (requests)"
})
# JavaScript example
js_sample = f"""const axios = require('axios');
const config = {{
method: '{method}',
url: 'https://api.example.com{path}',
headers: {{
'Authorization': 'Bearer YOUR_TOKEN',
'Content-Type': 'application/json'
}}"""
if method in ["post", "put", "patch"]:
js_sample += """,
data: {
name: 'example',
value: 123
}"""
js_sample += """
};
axios(config)
.then(response => {
console.log(JSON.stringify(response.data));
})
.catch(error => {
console.error(error);
});"""
samples.append({
"lang": "JavaScript",
"source": js_sample,
"label": "Node.js (axios)"
})
# Go example
go_sample = f"""package main
import (
"bytes"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
)
func main() {{
url := "https://api.example.com{path}"
"""
if method in ["post", "put", "patch"]:
go_sample += """ payload := map[string]interface{}{
"name": "example",
"value": 123,
}
jsonData, _ := json.Marshal(payload)
req, _ := http.NewRequest(""" + f'"{method.upper()}", url, bytes.NewBuffer(jsonData))'
else:
go_sample += f""" req, _ := http.NewRequest("{method.upper()}", url, nil)"""
go_sample += """
req.Header.Set("Authorization", "Bearer YOUR_TOKEN")
req.Header.Set("Content-Type", "application/json")
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
panic(err)
}
defer resp.Body.Close()
body, _ := ioutil.ReadAll(resp.Body)
fmt.Println(string(body))
}"""
samples.append({
"lang": "Go",
"source": go_sample,
"label": "Go (net/http)"
})
return samples
def _add_security_schemes(self, spec: Dict[str, Any]):
"""Add comprehensive security schemes"""
if "components" not in spec:
spec["components"] = {}
spec["components"]["securitySchemes"] = {
"bearerAuth": {
"type": "http",
"scheme": "bearer",
"bearerFormat": "JWT",
"description": "JWT token authentication"
},
"apiKey": {
"type": "apiKey",
"name": "X-API-Key",
"in": "header",
"description": "API key authentication"
},
"oauth2": {
"type": "oauth2",
"flows": {
"authorizationCode": {
"authorizationUrl": "https://auth.example.com/oauth/authorize",
"tokenUrl": "https://auth.example.com/oauth/token",
"refreshUrl": "https://auth.example.com/oauth/refresh",
"scopes": {
"read": "Read access to protected resources",
"write": "Write access to protected resources",
"admin": "Admin access to all resources"
}
},
"clientCredentials": {
"tokenUrl": "https://auth.example.com/oauth/token",
"scopes": {
"api": "API access"
}
}
}
},
"cookieAuth": {
"type": "apiKey",
"in": "cookie",
"name": "session_id",
"description": "Session cookie authentication"
}
}
def _add_server_variables(self, spec: Dict[str, Any]):
"""Add server variables for environment switching"""
spec["servers"] = [
{
"url": "https://{environment}.api.example.com/{version}",
"description": "API Server",
"variables": {
"environment": {
"enum": ["production", "staging", "development"],
"default": "production",
"description": "Server environment"
},
"version": {
"enum": ["v1", "v2", "v3"],
"default": "v2",
"description": "API version"
}
}
},
{
"url": "http://localhost:{port}",
"description": "Local development server",
"variables": {
"port": {
"enum": ["3000", "8000", "8080"],
"default": "8000",
"description": "Server port"
}
}
}
]
def _enhance_schemas(self, spec: Dict[str, Any]):
"""Enhance schemas with examples and additional properties"""
for schema_name, schema in spec.get("components", {}).get("schemas", {}).items():
if "properties" in schema:
# Add examples to properties
for prop_name, prop in schema["properties"].items():
if "example" not in prop:
prop["example"] = self._generate_example_for_type(prop)
# Add schema-level example
if "example" not in schema:
schema["example"] = {
prop_name: prop.get("example")
for prop_name, prop in schema["properties"].items()
}
def _generate_example_for_type(self, prop: Dict) -> Any:
"""Generate example based on property type"""
prop_type = prop.get("type", "string")
prop_format = prop.get("format", "")
examples = {
("string", "email"): "user@example.com",
("string", "date"): "2024-01-15",
("string", "date-time"): "2024-01-15T10:30:00Z",
("string", "uuid"): "550e8400-e29b-41d4-a716-446655440000",
("string", "uri"): "https://example.com/resource",
("string", "hostname"): "api.example.com",
("string", "ipv4"): "192.168.1.1",
("string", "ipv6"): "2001:0db8:85a3:0000:0000:8a2e:0370:7334",
("integer", ""): 42,
("number", ""): 123.45,
("boolean", ""): True,
("array", ""): ["item1", "item2"],
("object", ""): {"key": "value"}
}
return examples.get((prop_type, prop_format), "example")
def _add_tags_metadata(self, spec: Dict[str, Any]):
"""Add detailed tag descriptions"""
spec["tags"] = [
{
"name": "Authentication",
"description": "Authentication and authorization endpoints",
"externalDocs": {
"description": "Authentication guide",
"url": "https://docs.example.com/auth"
}
},
{
"name": "Users",
"description": "User management operations",
"externalDocs": {
"description": "User API documentation",
"url": "https://docs.example.com/users"
}
},
{
"name": "Products",
"description": "Product catalog management",
"externalDocs": {
"description": "Product API documentation",
"url": "https://docs.example.com/products"
}
},
{
"name": "Orders",
"description": "Order processing and management",
"externalDocs": {
"description": "Order API documentation",
"url": "https://docs.example.com/orders"
}
}
]
def export_documentation(self, output_dir: str = "./api-docs"):
"""Export documentation in various formats"""
output_path = Path(output_dir)
output_path.mkdir(parents=True, exist_ok=True)
# Get enhanced OpenAPI spec
spec = self.enhance_openapi()
# Export as JSON
with open(output_path / "openapi.json", "w") as f:
json.dump(spec, f, indent=2)
# Export as YAML
with open(output_path / "openapi.yaml", "w") as f:
yaml.dump(spec, f, default_flow_style=False, sort_keys=False)
# Generate AsyncAPI spec if websockets are used
asyncapi_spec = self._generate_asyncapi_spec()
if asyncapi_spec:
with open(output_path / "asyncapi.yaml", "w") as f:
yaml.dump(asyncapi_spec, f, default_flow_style=False)
# Generate Postman collection
postman_collection = self._convert_to_postman(spec)
with open(output_path / "postman_collection.json", "w") as f:
json.dump(postman_collection, f, indent=2)
# Generate README
self._generate_readme(spec, output_path)
print(f"Documentation exported to {output_path}")
def _generate_asyncapi_spec(self) -> Optional[Dict]:
"""Generate AsyncAPI spec for WebSocket/event-driven APIs"""
# Check if app has WebSocket routes
has_websocket = any(
hasattr(route, "endpoint") and "websocket" in str(route.endpoint)
for route in self.app.routes
)
if not has_websocket:
return None
return {
"asyncapi": "2.6.0",
"info": {
"title": f"{self.app.title} WebSocket API",
"version": self.app.version,
"description": f"WebSocket API for {self.app.title}"
},
"servers": {
"production": {
"url": "wss://api.example.com",
"protocol": "ws",
"description": "Production WebSocket server"
}
},
"channels": {
"/ws": {
"subscribe": {
"message": {
"$ref": "#/components/messages/notification"
}
},
"publish": {
"message": {
"$ref": "#/components/messages/command"
}
}
}
},
"components": {
"messages": {
"notification": {
"payload": {
"type": "object",
"properties": {
"type": {"type": "string"},
"data": {"type": "object"}
}
}
},
"command": {
"payload": {
"type": "object",
"properties": {
"action": {"type": "string"},
"params": {"type": "object"}
}
}
}
}
}
}
def _convert_to_postman(self, spec: Dict) -> Dict:
"""Convert OpenAPI to Postman Collection"""
# Implementation similar to JavaScript version
# Simplified for brevity
return {
"info": {
"name": spec["info"]["title"],
"schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json"
},
"item": []
}
def _generate_readme(self, spec: Dict, output_path: Path):
"""Generate comprehensive README"""
readme_content = f"""# {spec['info']['title']}
{spec['info'].get('description', '')}
## Version
{spec['info']['version']}
## Documentation
- [OpenAPI Specification](./openapi.json)
- [Postman Collection](./postman_collection.json)
- [AsyncAPI Specification](./asyncapi.yaml) (if applicable)
## Quick Start
```python
import requests
# Example API call
response = requests.get(
"https://api.example.com/endpoint",
headers={{"Authorization": "Bearer YOUR_TOKEN"}}
)
print(response.json())
```
## Authentication
See the OpenAPI specification for detailed authentication information.
## Support
{spec['info'].get('contact', {}).get('email', 'support@example.com')}
"""
with open(output_path / "README.md", "w") as f:
f.write(readme_content)
# FastAPI app example with enhanced documentation
app = FastAPI(
title="E-commerce API",
version="2.0.0",
description="Comprehensive e-commerce platform API"
)
enhancer = OpenAPIEnhancer(app)
# Override the default OpenAPI endpoint
@app.get("/openapi.json")
async def get_open_api_endpoint():
return enhancer.enhance_openapi()
# Export documentation
if __name__ == "__main__":
enhancer.export_documentation()
```
## Error Handling
| Error | Cause | Solution |
|-------|-------|----------|
| "No routes found" | Empty Express/FastAPI app | Ensure routes are defined before generation |
| "Invalid OpenAPI spec" | Malformed specification | Validate with online validators |
| "Schema extraction failed" | TypeScript/Pydantic issues | Check type definitions are correct |
| "Swagger UI not loading" | CORS or path issues | Check CORS settings and base path configuration |
| "Examples not generated" | Missing schema definitions | Ensure all models have proper schemas |
## Configuration Options
**Basic Usage:**
```bash
/generate-api-docs \
--framework=express \
--output=./api-docs \
--format=openapi3 \
--include-examples
```
**Available Options:**
`--framework <type>` - Web framework to analyze
- `express` - Express.js applications
- `fastapi` - FastAPI Python applications
- `spring` - Spring Boot applications
- `rails` - Ruby on Rails APIs
- `django` - Django REST framework
`--format <spec>` - Output specification format
- `openapi3` - OpenAPI 3.0.3 (default)
- `openapi2` - OpenAPI 2.0 (Swagger)
- `asyncapi` - AsyncAPI for event-driven
- `graphql` - GraphQL schema
`--output <path>` - Output directory for documentation
- Default: `./api-docs`
`--include-examples` - Generate request/response examples
- Analyzes codebase for real examples
- Creates synthetic examples from schemas
`--interactive-ui <type>` - Interactive documentation UI
- `swagger` - Swagger UI (default)
- `redoc` - ReDoc documentation
- `both` - Both UIs
- `none` - Static docs only
`--auth-docs` - Include authentication documentation
- Extracts auth middleware
- Documents OAuth flows
- Includes example tokens
`--sdk-generation` - Generate client SDKs
- `--languages` - Comma-separated list (js,python,go,java)
- `--sdk-output` - SDK output directory
`--postman` - Generate Postman collection
- Includes environment variables
- Pre-request scripts
- Test assertions
`--validate` - Validate generated specification
- Checks for completeness
- Validates examples
- Tests schema consistency
## Best Practices
DO:
- Keep API documentation in sync with code using CI/CD
- Include realistic examples from actual API usage
- Document all error responses and status codes
- Use consistent naming conventions across endpoints
- Include rate limiting and pagination information
- Document deprecated endpoints with sunset dates
- Provide "Try it out" functionality in docs
- Version your API documentation alongside code
DON'T:
- Expose sensitive information in examples
- Use production data in documentation
- Skip documenting edge cases and errors
- Forget to document authentication requirements
- Leave schemas without descriptions
- Mix API versions in single documentation
## Performance Considerations
- Large APIs (500+ endpoints) may take time to analyze
- Schema extraction from TypeScript can be memory-intensive
- Consider splitting documentation by module for very large APIs
- Cache generated documentation to avoid regeneration
- Use CDN for serving interactive documentation
## Security Considerations
- Never include real API keys or tokens in examples
- Sanitize any production data used in documentation
- Use separate documentation URLs for internal vs external APIs
- Implement authentication on documentation endpoints if needed
- Review generated schemas for accidentally exposed fields
## Troubleshooting
**Issue: Routes not detected**
```javascript
// Ensure routes are registered before doc generation
app.use('/api', apiRouter);
// Then generate docs
const docs = new APIDocumentationGenerator(app);
```
**Issue: TypeScript types not extracted**
```bash
# Install required packages
npm install --save-dev typescript ts-json-schema-generator
# Ensure tsconfig.json includes all source files
```
**Issue: Swagger UI CORS errors**
```javascript
// Enable CORS for documentation
app.use('/api-docs', cors({
origin: '*',
credentials: true
}));
```
## Related Commands
- `/api-contract-generator` - Design-first API specification
- `/api-mock-server` - Create mock server from OpenAPI spec
- `/api-sdk-generator` - Generate client libraries
- `/api-versioning-manager` - Manage API versions
- `/api-testing-framework` - Generate tests from spec
## Version History
- v1.0.0 (2024-10): Initial implementation with OpenAPI 3.0 support
- Planned v1.1.0: GraphQL introspection and AsyncAPI supportNo comments yet. Be the first to comment!
