AWS launches local emulator to test cloud code on your PC for free

Amazon Web Services has launched a desktop tool called the AWS Emulator. The software lets developers run AWS application programming interfaces locally on personal computers, development servers, or in continuous integration systems. Because the tests do not call the remote AWS infrastructure, the tool is free to use.

Lightweight Design Built in Rust

Amazon built the emulator with the Rust programming language. Daniel Abib, a senior specialist solutions architect at the company, noted that this keeps CPU and memory usage low enough to run smoothly on laptops.

The tool does not copy the entire remote cloud infrastructure. Instead, it serves local endpoints based on public AWS API models. The repository containing those models includes more than 1,300 items.

The emulator functions as a single account and lacks support for cross-account or cross-region setups. It also processes Identity and Access Management policies differently than the live cloud environment. To help builders know what works, Amazon provides fidelity scores that show how closely the local results match live services for valid and invalid calls.

Setup and AI Agent Support

Developers on Linux can download the emulator as a Debian or RPM package. Users on Mac and Windows computers must run it as a container image through Docker.

Upon starting, the tool automatically generates its own credentials, certificates, and configuration files. Developers then direct their software development kits or command-line scripts to the local endpoint, leaving their underlying code unchanged.

The company also released a dedicated skill for artificial intelligence coding agents. The agent scans a project, compares its dependencies against fidelity test scores, and flags which features may behave differently locally than in the real cloud.