AWS launches AWS Emulator

November 11, 2026

AWS launched AWS Emulator today, a local copy of AWS for coding agents and developers to test against. It is announced in Swami Sivasubramanian's guest post on All Things Distributed and in Matt Wood's Better feedback for building with agents. The source is on GitHub and the setup is in the AWS Emulator User Guide.

What AWS Emulator is

• Built from more than 400 API models covering more than 200 AWS services, and it runs free and offline on your own machine.
• All of its code was written and tested by agents. They work from fidelity tests, end-to-end scenarios derived from the public Smithy API models and corrected until they pass against real AWS, then build the emulator until it passes the same tests. Every change goes through a merge gate that includes security agents doing adversarial reviews.
• AWS compares the emulator's responses with recorded AWS responses and publishes the versioned tests and success rates, for whole scenarios and for individual steps. The tests are in aws-emulator-evaluation-suite and the scores ship with each release.
• Released under CC0. The commit history and every issue the agents filed are public, and issues/things-that-do-not-work/ lists the behaviors that do not match AWS yet.
• Available for Linux as an RPM or Debian package and, on macOS and Windows, as a Docker image you build from AWS's Dockerfile. It serves HTTPS on 127.0.0.1:9297 with a self-signed certificate.
• Telemetry is on by default; --telemetry off or EMULATOR_TELEMETRY=off turns it off.

Run it with Docker

From AWS's Getting started with Docker guide. In an empty directory, create a Dockerfile:

FROM public.ecr.aws/amazonlinux/amazonlinux:2023-minimal
ADD https://downloads.aws.com/aws-emulator/packages/aws-emulator/LTS/latest/aws-emulator-x86_64.rpm /tmp/aws-emulator.rpm
RUN rpm -i /tmp/aws-emulator.rpm && rm /tmp/aws-emulator.rpm \
    && mkdir -p /home/emulator && chown 1000 /home/emulator
USER 1000
ENV HOME=/home/emulator
EXPOSE 9297
ENTRYPOINT ["aws-emulator", "-b", "0.0.0.0"]

On Apple silicon or other Arm machines, use aws-emulator-aarch64.rpm. Then build and run it:

docker build -t aws-emulator .
mkdir -p ~/.aws/emulator
PORT=9297
docker run --rm --memory=2g --memory-swap=2g -p 127.0.0.1:$PORT:$PORT \
  -e HOME="$HOME" -v "$HOME/.aws/emulator:$HOME/.aws/emulator" \
  aws-emulator -p $PORT

To point your SDK at it, see Pointing your AWS SDK at AWS Emulator.

Limits AWS lists

• One Region and one account: it accepts any Region and account ID but does not keep resources separate by them.
• It does not evaluate IAM policies and resource-based policies the way AWS does.
• Resources live in memory and are deleted when it stops.
• Behavior is checked against AWS in us-west-2 only, global services in us-east-1.
• Made for test runs, not tested for long-running use or load testing.