AWS Ships a Free Local Copy of Its Cloud That It Says No Human Wrote or Reviewed
AWS released AWS Emulator on November 11, a free local emulator built from more than 400 API models covering more than 200 AWS services, so developers and coding agents can test against AWS APIs without an account or network calls. AWS says autonomous agents wrote all of the code and its team has not written or reviewed any of it, relying instead on agent-run tests checked against real AWS and an automated merge gate. The code is public under CC0; unsupported operations return 501 Not Implemented.
AWS is selling the absence of human review as a feature. Its new developer tool, a local copy of the AWS APIs, was written entirely by autonomous agents, and the engineer who led it says his team "hasn't written or reviewed any of the code." What AWS asks users to trust instead is the scaffolding: tests checked against the real cloud and an automated gate every change must pass.
What shipped#
AWS announced AWS Emulator on November 11. It runs on a developer's machine or in continuous integration, and the AWS CLI, SDKs and coding agents talk to it over a local endpoint using the same AWS APIs they would use in the cloud. No AWS account is required, and there is no added service fee, according to AWS.
- Coverage: built from more than 400 API models covering more than 200 AWS services, per AWS's launch posts and GeekWire. Services are generated from the API models AWS publishes for its SDKs.
- Behaviour: for operations it supports, AWS says the emulator returns the same results and errors as AWS; unsupported operations return 501 Not Implemented. State is held in memory, and each running copy gets its own port, keys and state.
- Licence and code: the source is on GitHub under CC0, a public-domain dedication. It is written in Rust and installs from Linux packages or runs in Docker on macOS and Windows.
How agents built it#
AWS senior principal engineer Matt Goldberg says the emulator is built by three teams of agents: one writes and maintains fidelity tests, one finds issues, and one fixes them, one agent per issue. Werner Vogels' blog, in a post by AWS's Swami Sivasubramanian, says the agents correct each test until it passes against real AWS and then build the emulator until it passes the same test. Every change goes through a merge gate that includes agents reviewing coding standards and security, and Goldberg says hundreds of agents now fix thousands of issues a day. The project began as a weekend experiment in which Kiro, Amazon's spec-driven coding agent, produced a rough version of the SQS queue service in about 15 minutes, GeekWire reports.
AWS publishes the agents' issue files in the repository, including a folder of behaviours that still do not match real AWS.
Limits#
- The claims about how the emulator was built, the absence of human-written code and the number of issues fixed come from AWS. We did not audit the commit history.
- "Same result as AWS" applies to supported operations; AWS points users to a fidelity report for how closely responses match, which we did not assess.
- Passing an emulator test is not the same as passing in production, where permissions, quotas and latency differ.
Sources#
- AWS News Blog: Test your applications against AWS locally with AWS Emulator (November 11, 2026)
- AWS What's New: AWS Emulator is now available (November 11, 2026)
- About Amazon: How we built the agents that built AWS Emulator (November 11, 2026)
- All Things Distributed: AWS Emulator and the engineer's job when agents write the code (November 11, 2026)
- GeekWire: AWS gives developers a free local stand-in for its cloud, built from scratch by AI agents (November 11, 2026)