Run AWS Emulator on your laptop with your AI agent, no account and no bill

What you get

AWS Emulator is the official local emulator that AWS open-sourced on November 11. It pretends to be AWS on your own computer, so common services like S3 and DynamoDB run locally. You don't need an AWS account, it creates no cloud bill, and everything is wiped when you shut it down. It covers more than 200 services, and its code was written entirely by AI agents. AWS also ships a Skill for it, so your AI agent can install and connect it on its own and troubleshoot errors itself. This tutorial gives you 3 copy-paste prompts so your AI agent can point your project at the local emulator and run your tests.

Set your expectations first. It's good for trying things out and running tests locally over and over. It's not for testing permissions or security. It doesn't check IAM permission policies, all regions and accounts share one space, and all data is gone after a restart. Step 3 shows how your AI agent can check, feature by feature, which parts you can trust.

Why it's worth using

Writing AWS projects is painful because every change has to be deployed to the real cloud. You need an account and permissions, you might forget to delete a resource and get charged, and a half-finished test run can mess up your production data. A local emulator moves that whole loop onto your computer.

Free, no account needed: when it starts, it generates its own temporary credentials, which only work for that run.
Same usage as real AWS: the AWS CLI and the official SDK for each language connect by changing only the address, so your code stays the same.
Clean every time: data only lives in memory. Shut it down and it's gone, so tests never interfere with each other.

Step 1: Have your AI agent install the official Skill and start the emulator

The official route is to let your AI agent handle the setup. First it installs a Skill called aws-emulator (think of it as a usage manual written for AI), which handles installation and connection. It also deals with the errors that usually get stuck, like certificates and signing. Send the prompt below to your AI agent.

Help me install AWS Emulator, AWS's official local emulator (https://github.com/aws/aws-emulator), on this computer.
1. First check the AWS CLI version. It needs to be 2.35.0 or newer. If it's older, tell me how to upgrade and wait for my approval before installing anything
2. Install the aws-emulator Skill with the official command, then follow the Skill's instructions to install and start the emulator
3. On Mac and Windows, the emulator runs in Docker, so first confirm Docker is running. On Linux, use the official installation package
4. After it starts, run a health check, then check the current identity to confirm you're talking to the emulator (the account should be 000000000000), not my real AWS account
5. Turn off usage data reporting for the emulator
6. Ask me before using sudo or changing my shell configuration files

Why step 4 matters: connecting to the wrong place is the most dangerous mistake. Once the account shows as twelve zeros, you know every later operation stays local and can't touch your real AWS.

Step 2: Point your project at the local emulator

By default, the emulator waits at https://127.0.0.1:9297. To connect your project, you only need to change a few environment variables: the address, the temporary credentials file, the certificate file, and the region. The emulator generates these paths when it starts, so the easiest approach is to have your AI agent set them up.

New accounts get 10 free credits, plus 1 more for each daily check-in. Spend 1 credit to unlock and it stays open for you.

Why use a separate file: the official docs warn that the config file for the emulator can override your normal AWS settings. Loading it separately means your everyday AWS CLI stays untouched.

Step 3: Have your AI agent check which features you can rely on

The emulator is more faithful for some services than others, so the official docs give each one a "fidelity" score. Every service runs a set of comparison tests, and the score shows how many of them pass. The scores are published with each release. Operations that aren't implemented yet return a "not implemented" error. Have your AI agent run the check for you.

Use the aws-emulator Skill to check my project:
1. List all the AWS services and operations the project uses
2. Compare them with the official fidelity tests and the scores for the latest release. Tell me which ones I can safely test locally, and which have low scores or no test coverage
3. For anything without coverage, suggest how I should test it: leave it for testing on real AWS, or accept the local result
4. If you find behavior that differs from real AWS, draft an issue for me to review. Don't submit it

Notes

Don't use it to test permissions or security. IAM and resource policies aren't checked the way AWS checks them, so the emulator won't block a wrong permission setup.
One emulator models one region and one account. To test multiple regions, start one on a different port for each.
Data only lives in memory. It's wiped on shutdown, and it hasn't been verified for long-running workloads or stress tests.
It sends usage data by default. If you don't want that, ask your AI agent to add the flag that turns it off.
The source code is released under CC0. The repo doesn't accept outside code contributions, so send feedback through GitHub Issues.

Frequently asked questions

Is AWS Emulator free? Yes. It costs nothing to use, and you don't need an AWS account. It's a local program that AWS open-sourced. It generates temporary credentials when it starts, and it handles every request on your own computer.

AWS Emulator vs LocalStack: which should you use? AWS Emulator is built by AWS itself. LocalStack is a third-party tool that does a similar job. AWS's docs don't compare the two, so before you choose, ask your AI agent to use the method in Step 3 to check how well your project is supported in each.

Does AWS Emulator need Docker? On Linux, you can install the official RPM or Debian package directly, with no Docker. On Mac and Windows, it currently runs in a Docker container, and AWS provides a ready-made Dockerfile.

Which services does AWS Emulator support? It's generated from more than 400 AWS API definitions and covers over 200 services. SQS was the first one built. Fidelity varies by service, so check the fidelity score published with each release.

Can AWS Emulator test Terraform, CloudFormation and CDK? You can connect them, but support depends on the service. AWS says control plane behavior is the most faithful, while the data plane and the infrastructure-as-code parts are still being filled in. Run the Step 3 check before you rely on it.