API versioning in Ruby on Rails - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is API versioning in Rails?

API versioning is a way to manage changes in your API over time by creating different versions. This helps keep old clients working while allowing new features in newer versions.

beginner

Name two common ways to version an API in Rails.

1. Using URL path versioning (e.g., /api/v1/)<br>2. Using HTTP headers to specify the version

intermediate

How do you set up URL path versioning in Rails routes?

You add a version segment in your routes like:<br>namespace :api do<br> namespace :v1 do<br> resources :posts<br> end<br>end<br>This creates routes under /api/v1/posts.

beginner

Why is API versioning important for backward compatibility?

It allows old clients to keep working with the API without breaking, even when new features or changes are added in newer versions.

intermediate

What is a downside of using URL path versioning?

It can lead to duplicated code and more maintenance because each version might need separate controllers and views.

Which of these is a common way to version an API in Rails?

A Using URL path segments like /api/v1/

B Changing the database schema for each version

C Using CSS classes to mark versions

D Renaming the Rails app folder

API versioning commonly uses URL path segments or HTTP headers, not database schema changes or CSS.

What does the namespace :v1 do in Rails routes?

A Updates the Rails version

B Changes the database version

C Groups routes under /v1/ path

D Creates a new model

Namespace :v1 groups routes under the /v1/ URL path, helping organize API versions.

Why might you use HTTP headers for API versioning instead of URL paths?

A Because headers are easier to see in the browser

B To keep URLs clean and separate version info

C To avoid using JSON

D To speed up the server

Using HTTP headers keeps URLs clean and moves version info to request headers.

What is a risk if you don’t version your API?

A Old clients may break when API changes

B The app will run faster

C You get more users

D The database will auto-update

Without versioning, changes can break old clients relying on previous API behavior.

In Rails, where do you usually put versioned API controllers?

A In the config folder

B In the root app/controllers folder only

C In the assets folder

D In folders matching the version, like app/controllers/api/v1/

Versioned API controllers are organized in folders by version to keep code clear and separate.

Explain how you would add versioning to a Rails API using URL paths.

Think about how URLs and folders help organize versions.

Why is API versioning important when you update your API?

Consider what happens if you change the API without warning.