Amplify Gen 1 vs Gen 2

AWS Amplify Gen 2 is a complete rewrite of the Amplify experience. Understanding the differences will help you navigate documentation and avoid confusion.

The Evolution of Amplify

AWS Amplify was originally released in 2017 and has evolved significantly. In late 2023, AWS announced Amplify Gen 2, which represents a fundamental shift in how you define and manage your backend.

Aspect	Gen 1 (Legacy)	Gen 2 (Current)
Backend Definition	CLI prompts & GraphQL schema files	TypeScript code in amplify/ folder
CLI Command	amplify	ampx
Initialization	amplify init	npx ampx sandbox
Schema Language	GraphQL SDL (.graphql files)	TypeScript with schema builder
Type Safety	Generated after build	Built-in, real-time
Infrastructure	CloudFormation templates	AWS CDK (under the hood)
Local Development	Mock server (amplify mock)	Sandbox (ampx sandbox)

Key Differences Explained

1. TypeScript-First Approach

The biggest change is how you define your backend. In Gen 1, you answered CLI prompts and wrote GraphQL schema files:

# Gen 1: GraphQL Schema (schema.graphql)
type Todo @model @auth(rules: [{ allow: owner }]) {
  id: ID!
  content: String!
  completed: Boolean
}

In Gen 2, you write TypeScript code that's fully type-safe:

// Gen 2: TypeScript Schema (amplify/data/resource.ts)
import { a, defineData, type ClientSchema } from '@aws-amplify/backend';

const schema = a.schema({
  Todo: a.model({
    content: a.string().required(),
    completed: a.boolean().default(false),
  }).authorization(allow => [allow.owner()]),
});

export type Schema = ClientSchema<typeof schema>;
export const data = defineData({ schema });

2. The CLI Change: amplify → ampx

Gen 2 uses a new CLI called ampx. Here's a comparison of common commands:

Action	Gen 1 Command	Gen 2 Command
Initialize project	amplify init	npx ampx sandbox
Add authentication	amplify add auth	Write amplify/auth/resource.ts
Add data/API	amplify add api	Write amplify/data/resource.ts
Push changes	amplify push	Automatic (sandbox watches files)
Deploy	amplify publish	Git push to connected repo
Generate types	amplify codegen	npx ampx generate graphql-client-code

3. Sandbox vs Mock

In Gen 1, amplify mock created a local simulation of your backend. In Gen 2, ampx sandbox creates actual AWS resources but isolated per developer:

The sandbox:

• Deploys real AWS resources (DynamoDB tables, Cognito pools, etc.)
• Watches your amplify/ folder for changes
• Automatically redeploys when you modify resources
• Creates an amplify_outputs.json file for your frontend
• Is isolated to your AWS account and branch

4. CDK Under the Hood

Gen 1 used CloudFormation templates directly, which were complex and hard to customize. Gen 2 is built on AWS CDK, giving you the ability to extend and customize resources when needed:

// You can access the underlying CDK constructs if needed
import { defineBackend } from '@aws-amplify/backend';
import { auth } from './auth/resource';
import { data } from './data/resource';

const backend = defineBackend({
  auth,
  data,
});

// Access CDK constructs for advanced customization
const authStack = backend.auth.stack;
// Add custom CDK code here...

Why AWS Made This Change

AWS rebuilt Amplify Gen 2 to address common developer feedback:

1. Better Developer Experience – TypeScript provides autocomplete and error checking
2. Version Control Friendly – Everything is code, making PRs and reviews easy
3. Customization – CDK access allows you to extend beyond Amplify's defaults
4. Faster Iteration – Sandbox with hot-reload makes development faster
5. Team Collaboration – Each developer can have their own sandbox

Identifying Gen 1 vs Gen 2 Code

When searching online, you might find outdated Gen 1 tutorials. Here's how to tell them apart:

Summary

• Gen 2 is the current version of Amplify (released late 2023)
• Uses TypeScript code instead of GraphQL schemas and CLI prompts
• The CLI command changed from amplify to ampx
• Sandbox replaces mock with real AWS resources per developer
• Built on AWS CDK for better customization
• Look for Gen 2 indicators when following tutorials