Api Changelog Versioning

API Changelog & Versioning

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• Best Practices

Overview

Create comprehensive API changelogs that document changes, deprecations, breaking changes, and provide migration guides for API consumers.

When to Use

• API version changelogs
• Breaking changes documentation
• Migration guides between versions
• Deprecation notices
• API upgrade guides
• Backward compatibility notes
• Version comparison

Quick Start

• Version comparison

````markdown

API Changelog

Version 3.0.0 - 2025-01-15

🚨 Breaking Changes

Authentication Method Changed

Previous (v2):

GET /api/users
Authorization: Token abc123

Reference Guides

Detailed implementations in the references/ directory:

Best Practices

✅ DO

• Clearly mark breaking changes
• Provide migration guides with code examples
• Include before/after comparisons
• Document deprecation timelines
• Show impact on existing implementations
• Provide SDKs for major versions
• Use semantic versioning
• Give advance notice (3-6 months)
• Maintain backward compatibility when possible
• Document version support policy

❌ DON'T

• Make breaking changes without notice
• Remove endpoints without deprecation period
• Skip migration examples
• Forget to version your API
• Change behavior without documentation
• Rush deprecations

🚨 Breaking Changes

🚨 Breaking Changes

Authentication Method Changed

Previous (v2):

GET /api/users
Authorization: Token abc123

````

Current (v3):

GET /api/v3/users
Authorization: Bearer eyJhbGciOiJIUzI1NiIs...

Impact: All API consumers must switch from API tokens to JWT Bearer tokens

Migration Steps:

1. Obtain JWT token from /api/v3/auth/login endpoint 2. Replace Authorization: Token with Authorization: Bearer 3. Update token refresh logic (JWT tokens expire after 1 hour)

Migration Deadline: June 1, 2025 (v2 auth will be deprecated)

Migration Guide: JWT Authentication Guide

---

Response Format Changed

Previous (v2):

{
  "id": "123",
  "name": "John Doe",
  "email": "john@example.com"
}

Current (v3):

{
  "data": {
    "id": "123",
    "type": "user",
    "attributes": {
      "name": "John Doe",
      "email": "john@example.com"
    }
  }
}

Impact: All API responses now follow JSON:API specification

Migration:

// Before (v2)
const user = await response.json();
console.log(user.name);

// After (v3)
const { data } = await response.json();
console.log(data.attributes.name);

// Or use our SDK which handles this automatically
import { ApiClient } from "@company/api-sdk";
const user = await client.users.get("123");
console.log(user.name); // SDK unwraps the response

---

Removed Endpoints

---

🔧 Improvements

🔧 Improvements

Performance Enhancements

• 50% faster response times for list endpoints
• Database query optimization reducing average query time from 150ms to 50ms
• Caching layer added for frequently accessed resources
• CDN integration for static assets

Benchmark Comparison:

---

Better Error Messages

Before (v2):

{
  "error": "Validation failed"
}

After (v3):

{
  "errors": [
    {
      "code": "VALIDATION_ERROR",
      "field": "email",
      "message": "Email format is invalid",
      "suggestion": "Use format: user@example.com"
    },
    {
      "code": "VALIDATION_ERROR",
      "field": "password",
      "message": "Password too weak",
      "suggestion": "Password must be at least 8 characters with uppercase, lowercase, and numbers"
    }
  ]
}

---

Enhanced Rate Limiting

New rate limit headers in every response:

HTTP/1.1 200 OK
X-RateLimit-Limit: 1000
X-RateLimit-Remaining: 950
X-RateLimit-Reset: 1642694400
X-RateLimit-Window: 3600
Retry-After: 3600

Rate Limits by Plan:

---

✨ New Features

✨ New Features

Webhook Support

Subscribe to real-time events:

POST /api/v3/webhooks
Content-Type: application/json

{
  "url": "https://your-app.com/webhook",
  "events": ["user.created", "user.updated", "user.deleted"],
  "secret": "your-webhook-secret"
}

Webhook Payload:

{
  "event": "user.created",
  "timestamp": "2025-01-15T14:30:00Z",
  "data": {
    "id": "123",
    "type": "user",
    "attributes": {
      "name": "John Doe",
      "email": "john@example.com"
    }
  }
}

Documentation: Webhook Guide

---

Batch Operations

Process multiple records in a single request:

POST /api/v3/users/batch
Content-Type: application/json

{
  "operations": [
    {
      "method": "POST",
      "path": "/users",
      "body": { "name": "User 1", "email": "user1@example.com" }
    },
    {
      "method": "PATCH",
      "path": "/users/123",
      "body": { "name": "Updated Name" }
    },
    {
      "method": "DELETE",
      "path": "/users/456"
    }
  ]
}

Response:

{
  "results": [
    { "status": 201, "data": { "id": "789", ... } },
    { "status": 200, "data": { "id": "123", ... } },
    { "status": 204 }
  ]
}

Limits: Maximum 100 operations per batch request

---

Field Filtering

Request only the fields you need:

GET /api/v3/users/123?fields=id,name,email

Before (full response):

{
  "data": {
    "id": "123",
    "type": "user",
    "attributes": {
      "name": "John Doe",
      "email": "john@example.com",
      "phone": "+1234567890",
      "address": { "street": "123 Main St", "city": "NYC" },
      "preferences": {
        /* ... */
      },
      "metadata": {
        /* ... */
      }
      // ... many more fields
    }
  }
}

After (filtered response):

{
  "data": {
    "id": "123",
    "type": "user",
    "attributes": {
      "name": "John Doe",
      "email": "john@example.com"
    }
  }
}

Benefits:

• Reduced response size (up to 80% smaller)
• Faster response times
• Lower bandwidth usage

---

🔒 Security

🔒 Security

• TLS 1.3 Required: Dropped support for TLS 1.2
• JWT Expiry: Tokens now expire after 1 hour (was 24 hours)
• Rate Limiting: Stricter limits on authentication endpoints
• CORS: Updated allowed origins (see security policy)
• Input Validation: Enhanced validation on all endpoints

---

🗑️ Deprecated

Deprecation Schedule

Deprecation Warnings:

All deprecated features return a warning header:

HTTP/1.1 200 OK
Deprecation: true
Sunset: Sat, 01 Jun 2025 00:00:00 GMT
Link: <https://docs.example.com/migration/v2-to-v3>; rel="deprecation"

---

📊 Version Support Policy

Support Levels:

• Current: Full support, new features
• Maintenance: Bug fixes and security patches only
• End of Life: No support, upgrade required

---

Step 1: Update Base URL

Step 1: Update Base URL

// Before
const API_BASE = "https://api.example.com/api";

// After
const API_BASE = "https://api.example.com/api/v3";

Step 2: Migrate Authentication

// Before (v2) - API Token
const response = await fetch(`${API_BASE}/users`, {
  headers: {
    Authorization: `Token ${apiToken}`,
  },
});

// After (v3) - JWT Bearer
const tokenResponse = await fetch(`${API_BASE}/auth/login`, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ email, password }),
});
const { token } = await tokenResponse.json();

const response = await fetch(`${API_BASE}/users`, {
  headers: {
    Authorization: `Bearer ${token}`,
  },
});

Step 3: Update Response Parsing

// Before (v2)
const user = await response.json();
console.log(user.name);

// After (v3) - Unwrap data object
const { data } = await response.json();
console.log(data.attributes.name);

// Or use SDK
import { ApiClient } from "@company/api-sdk";
const client = new ApiClient(token);
const user = await client.users.get("123");
console.log(user.name); // SDK handles unwrapping

Step 4: Update Error Handling

// Before (v2)
try {
  const response = await fetch(`${API_BASE}/users`);
  if (!response.ok) {
    const error = await response.json();
    console.error(error.error);
  }
} catch (error) {
  console.error(error);
}

// After (v3) - Handle multiple errors
try {
  const response = await fetch(`${API_BASE}/users`);
  if (!response.ok) {
    const { errors } = await response.json();
    errors.forEach((err) => {
      console.error(`${err.field}: ${err.message}`);
      console.log(`Suggestion: ${err.suggestion}`);
    });
  }
} catch (error) {
  console.error(error);
}

Step 5: Update Pagination

// Before (v2)
const response = await fetch(`${API_BASE}/users?page=1&per_page=20`);

// After (v3)
const response = await fetch(`${API_BASE}/users?page[number]=1&page[size]=20`);

// Response structure
{
  "data": [...],
  "meta": {
    "page": {
      "current": 1,
      "size": 20,
      "total": 150,
      "totalPages": 8
    }
  },
  "links": {
    "first": "/api/v3/users?page[number]=1",
    "last": "/api/v3/users?page[number]=8",
    "next": "/api/v3/users?page[number]=2",
    "prev": null
  }
}

Step 6: Testing

// Run tests against v3 API
npm run test:api -- --api-version=v3

// Test migration gradually
const USE_V3 = process.env.USE_API_V3 === 'true';
const API_BASE = USE_V3
  ? 'https://api.example.com/api/v3'
  : 'https://api.example.com/api/v2';

---