Amazon releases free AWS cloud emulator built by AI agents

Amazon Web Services on Wednesday, November 11, released AWS Emulator. It's a free local emulator that lets developers and AI coding agents test code against AWS APIs on their own machines, and its code was written entirely by autonomous agents. The tool is generally available now and has no additional service fee. Developers pay only for AWS resources they later deploy in the cloud, according to AWS's launch post.aws.amazon.com

"The emulator was written entirely by autonomous agents. Our team hasn't written or reviewed any of the code," wrote Matt Goldberg, the AWS senior principal engineer behind the project, as quoted by GeekWire. SiliconANGLE reported that AWS is pitching the tool as a fix for a growing bottleneck: coding agents produce code faster than teams can check it against real cloud infrastructure.siliconangle.com+1

How it works

The emulator is written in Rust and serves a local HTTPS endpoint. The AWS CLI and SDKs can be pointed at it with environment variables, so application code doesn't change. It installs from RPM or Debian packages on Linux and runs in Docker on macOS and Windows, AWS said. The current version supports 438 public AWS API models covering more than 200 services, The New Stack reported.thenewstack.io+1

AWS publishes per-service "fidelity" scores showing how closely the emulator matches real AWS behavior, and the test suite is public. Operations that haven't been built yet return an HTTP 501 error. At launch, the emulator does not evaluate IAM policies the way AWS does, and it works as a single account with no cross-account or cross-Region behavior, AWS noted.aws.amazon.com

Built and maintained by agents

The project started as a weekend experiment. Goldberg's first prompt to Kiro, AWS's coding agent, produced a passable version of Amazon SQS in 15 minutes, GeekWire reported. Agents on Amazon Bedrock AgentCore now work in three teams. One writes fidelity tests and checks them against real AWS, a second runs those tests against the emulator and files issues, and a third fixes them. Every change then passes through a security-reviewed merge gate.geekwire.com

The code is released under a CC0 public-domain dedication. AWS's Tom Callaway told The New Stack that the company wasn't sure agent-made work could be copyrighted, and that it will take issues from users but not pull requests. "The agents will be doing that," he said.thenewstack.io

A crowded field

The launch comes after LocalStack, the best-known third-party AWS emulator, archived its open-source Community edition in March 2026 and began requiring an account and auth token, according to Cloudparts. Several community alternatives have appeared since then.cloudparts.dev

AWS vice president Swami Sivasubramanian framed the launch as a shift in what engineers do. "When agents write the code and check their own work, the engineer's job is to give them room to work on their own and to build the specs, tests, and merge gates that decide when that work is correct," he wrote on All Things Distributed.allthingsdistributed.com