By AWS released Blocks in public preview last week — an open-source TypeScript framework that runs your entire backend locally without an AWS account, then deploys the same code to production Lambda, Aurora, Cognito, and S3 with zero changes. No YAML. No CloudFormation files. One npm create command. If you have been quietly giving up on AWS Amplify because it turned into a configuration archaeology project, AWS Blocks is worth paying attention to.
The Problem Blocks Is Solving
AWS has given full-stack developers a rough ride. Amplify Gen2 abstracts infrastructure behind category-based primitives (Data, Auth, Storage, Functions) that work well until they don’t — and when they don’t, you are staring at the gap between what the console shows and what your CLI thinks is deployed. CDK is the other option, but CDK is an infrastructure tool that happens to be in TypeScript, not a developer tool.
Blocks sits between them. It lets you define backend capabilities in TypeScript, run them locally with in-memory mocks, and deploy to real AWS services without touching a single infrastructure file. The TypeScript you write for your backend becomes the AWS infrastructure that runs it — same code, different runtime contexts.
Getting Started in Two Commands
The local development story is the strongest part of this release:
npm create @aws-blocks/blocks-app@latest my-app
cd my-app && npm install
npm run dev # → http://localhost:3000That spins up a full local environment with every Block running an in-memory implementation. Postgres, authentication, file storage, real-time messaging — all running on your machine with no AWS credentials required. When you are ready to deploy, the same application code hits real AWS services: Aurora Serverless for Postgres, Cognito for auth, S3 for storage.
You define your backend in aws-blocks/index.ts:
import { database, auth, storage } from '@aws-blocks/blocks'
export const db = database.postgres()
export const userAuth = auth.cognito()
export const files = storage.s3()Your frontend imports those directly:
import { db, files } from 'aws-blocks'Types flow end to end with no code generation step. This is the developer experience AWS should have shipped with Amplify years ago.
Built for AI Agents, Not Just Humans
The detail that most coverage has glossed over: Blocks ships with built-in steering files that guide AI coding agents toward correct AWS patterns. When you ask Kiro, Cursor, or Claude Code to “add authentication and a database,” the agent produces code that works locally and deploys to production-grade AWS services because the framework constrains it to known-correct patterns.
This is the part that matters for 2026. AI agents writing backend code is not hypothetical — it is happening in production. Without guardrails, agents hallucinate AWS configurations that pass local tests and break on deploy. Blocks addresses this at the framework level rather than the prompt level. That is an architectural decision, not a marketing talking point.
What You Get at Preview
Approximately 20 Blocks are available now:
- Databases: PostgreSQL (via Aurora Serverless), DynamoDB
- Authentication: Amazon Cognito
- AI and agents: Amazon Bedrock (AI agents, knowledge bases)
- Storage: Amazon S3
- Messaging: Real-time messaging (AppSync/WebSockets)
- Jobs: Background jobs, scheduled tasks
- Email: Amazon SES
Frontend frameworks supported at preview: Vite + React, Next.js, Nuxt, and Astro. Mobile client codegen is on the roadmap for Kotlin, Swift, and Dart. AWS Blocks itself costs nothing — you pay only for the underlying AWS services your application consumes.
Blocks vs Amplify vs CDK: The Honest Take
These three tools are not in direct competition — they solve different problems for different audiences. But if you are a full-stack developer choosing one, here is the breakdown.
Amplify Gen2 is the right choice if you want AWS to make all infrastructure decisions for you and you are building a standard web or mobile app. It falls apart when your requirements diverge from its category model.
CDK is the right choice when infrastructure precision matters more than developer experience — multi-account deployments, complex networking, reusable internal modules. It has a real learning curve and is not designed for app-first development.
Blocks targets the space between them: full-stack developers who want backend capabilities without infrastructure management, but who also need transparency when things go wrong. The CDK escape hatch (Blocks generates CDK constructs) means you are not trapped if you outgrow a Block’s capabilities.
Preview Caveats Worth Knowing
This is version 0.1.x. Block constructor signatures may change between releases — DevelopersIO’s hands-on testing flagged this and recommends pinning versions for any reproducibility requirements. There is no GA timeline announced. The framework is AWS-only; if multi-cloud is a requirement, this is not the tool.
That said, the local development experience is real and testable today. Try it on a side project before committing to anything production-bound.
Get Started
The AWS Blocks GitHub repository has the full source and template options. The official getting started guide walks through your first local run and deployment. InfoQ’s coverage has additional context on the AWS Summit announcement and the AI-agent design rationale.
AWS Blocks is in preview and will change. But the zero-AWS-account local development model and the AI-agent steering files are real differentiators — enough to warrant a closer look if you are building on AWS and have ever wished Amplify would just get out of your way.
