Amazon Web Services has released a free local copy of its cloud that developers and AI coding agents can run on their own machines, and the company says its own engineers did not write a single line of the code. AWS Emulator launched on Wednesday, 11 November 2026, simulating more than 200 AWS services from over 400 public API models.

The tool is aimed at a problem that AI coding agents have made worse. Agents such as Amazon's Kiro and Anthropic's Claude Code can now write software far faster than teams can test it against the real cloud, and every test run in the cloud adds delay and cost. The emulator lets agents run their write-run-read loop locally, creating resources, inspecting the results and revising their code without a network connection or an AWS account.

In what Amazon is presenting as a selling point, the emulator was written and tested entirely by autonomous AI agents. The project began as a weekend experiment by senior principal engineer Matt Goldberg, who gave the Kiro coding agent a three-step prompt: write tests from the public API models, validate them against real AWS, and build an in-memory implementation that passed them. Kiro produced a passable version of Amazon SQS, the message queuing service, in about 15 minutes, and a rough version of the rest of AWS by the end of the weekend. Goldberg's team started using it to test its own software the following Monday.

Three teams of agents now build and maintain the emulator. One writes "fidelity tests" — real-world scenarios such as creating a queue, sending a message and deleting it — and checks each against real AWS. A second runs those tests against the emulator and files issues for failures, and a third fixes them, one agent per issue. Every change passes through an automated merge gate where other agents check coding standards and security. Goldberg wrote that hundreds of agents now fix thousands of issues a day.

The emulator is released under CC0, a public-domain dedication, with the full commit history public on GitHub, along with a folder called "things-that-do-not-work" listing behaviours the agents have found that do not yet match real AWS. There is no fee, and developers keep paying only for the real AWS resources they eventually deploy.

It has clear limits. An IDC analyst told InfoWorld the emulator does not yet simulate throttling, outages or differences in which services and features are available by region, and it does not sandbox the code it runs. It also does not evaluate AWS Identity and Access Management policies the way real AWS does, so a request the cloud would deny could succeed locally. Amazon says the tool is for building and testing, not for production workloads or security testing, and it plans to share more at its re:Invent conference.

The release also lands as a challenge to LocalStack, the best-known existing AWS emulator, which this year put its free version behind an account requirement and limited it to non-commercial use. AWS's version is free, offline and open, and its most striking claim is about how it was made: a piece of cloud infrastructure built by the same kind of agents it is designed to serve.

Sources: GeekWire and All Things Distributed (AWS).