Migration Guides — Helping Clients Upgrade

In this tutorial, you will learn about Migration Guides. We cover key concepts, practical examples, and best practices to help you master this topic.

Migration guides help API clients upgrade from one version to another with clear instructions, code examples, change summaries, and timelines.

Guide Structure

Summary of changes, step-by-step migration instructions, before/after code examples for each change, common migration pitfalls, testing instructions, and rollback plan.

Example

# Migrating from API v1 to v2

## Key Changes
- Response format changed from camelCase to snake_case
- Authentication now requires Bearer token
- Pagination parameters renamed

## Before (v1)
GET /api/v1/users HTTP/1.1
Response: { "users": [{"firstName": "Alice"}] }

## After (v2)
GET /api/v2/users HTTP/1.1
Response: { "data": [{"first_name": "Alice"}] }

Common Mistakes

1. No migration guide — Clients figure out changes themselves.
2. Incomplete examples — Only showing one of multiple changes.
3. No timeline — Clients do not know the deadline.

Practice Questions

1. What sections should a migration guide include?
2. Why include before/after code examples?
3. What timeline information should be included?

Challenge

Write a complete migration guide from v1 to v2 of a sample API. Include authentication change, response format change, and parameter rename.

What's Next

In the next lesson, you will learn versioning REST APIs with API gateways.