Amazon Web Services launched AWS Emulator on November 11, 2026, a local emulator of the AWS APIs for use on a computer or in a continuous integration (CI) environment, with no AWS account. In its What's New post, AWS said software development kit (SDK) and command-line interface (CLI) calls "go to AWS Emulator and come back in milliseconds", and that the tool has "no additional service fee."

#What changed?

The GitHub README describes AWS Emulator as "a local emulator of the AWS APIs" and "a local program that serves an AWS API endpoint" with "no graphical interface." Developers point the AWS CLI or an AWS SDK at that endpoint with environment variables, then "create and manage resources with the same AWS SDK and AWS CLI calls you use with AWS, signed with credentials the emulator provides."

Services "are generated from the API models AWS publishes, the same models behind the AWS SDKs." "When AWS adds a service or API, it shows up in AWS Emulator, and its behavior is filled in and verified release by release."

"For the operations it supports, AWS Emulator returns the same result as AWS for valid calls and the same errors for invalid ones." "Operations it doesn’t yet support return 501 Not Implemented." The fidelity guide says the emulator "matches AWS most closely for control plane APIs." "Fidelity for data plane APIs, and support for infrastructure as code tools such as AWS CloudFormation, Terraform, and the AWS CDK, varies by service." AWS publishes fidelity scores with each GitHub release. The README points to a public backlog of gaps under issues/things-that-do-not-work/.

The User Guide states: "AI agents keep the emulator up to date with AWS." It says the emulator "improves continuously, with updates many times a day". The product page includes a link titled "Read how AI agents built AWS Emulator".

SiliconANGLE's Mike Wheatley reported that AWS Senior Principal Engineer Matt Goldberg said in a blog post that "the entire service was designed and written exclusively by AI agents, with not even a single line of its code written or reviewed by a human engineer." Wheatley, citing Goldberg, described a 15-minute AWS Kiro rebuild of Amazon Simple Queue Service, three teams of "dozens of autonomous agents running on Amazon Bedrock AgentCore", and "an automated merge gate that’s supervised by adversarial security agents to check for any vulnerabilities." SiliconANGLE said the suite can "replicate hundreds of the company’s cloud services on developer’s workstations." AWS's own pages give no service count and do not state that no human wrote or reviewed the code.

#Who can use it and when?

"AWS Emulator doesn’t depend on an AWS Region." The README says: "You don’t need an AWS account." The User Guide and product page describe these install paths:

Platform

How it runs

Linux (x86_64 or aarch64)

Native binary from an RPM or Debian package, with no container runtime

macOS

Docker, from an image built with AWS's Dockerfile

Windows

Docker, from an image built with AWS's Dockerfile

Rust tests with the AWS SDK for Rust

Embedded mode, inside the test process

"AWS Emulator has no additional service fee. You pay only for AWS resources when you deploy to AWS." The README and product page say the source is under the CC0 1.0 Universal public domain dedication, except the code in the vendor/ directory, which is under the Apache License 2.0. The What's New post mentions only the CC0 dedication. The README and product page add the vendor exception.

#What are the limits?

The README says: "AWS Emulator is for building and testing. Don’t use it for production workloads or to test security." The product page says: "It offers no durability, availability or security guarantees."

The User Guide says: "The emulator doesn’t evaluate AWS Identity and Access Management (IAM) policies and resource-based policies the way AWS does." "The emulator accepts any Region and account ID in a request, but it doesn’t keep resources separate by Region or account." AWS tells users to use one Region and one account for all requests to an emulator, or a separate emulator on its own port for each Region. It says it verifies behavior in US West (Oregon), us-west-2, only, except global services in US East (N. Virginia), us-east-1, and that differences in service and feature availability across Regions are not reflected.

"AWS Emulator keeps the state of your resources in memory until you stop it." Each copy gets "its own port, keys and in-memory state, so agents, test suites, and CI jobs never see each other’s resources." "We haven’t tested the emulator for long-running use or load testing."

Telemetry is on by default and can be turned off. AWS says: "Its records never include what’s in your requests or responses, your code, your credentials, or personal data." The User Guide says the emulator "doesn’t send your requests, responses, or resource data to AWS", and that by default it sends "anonymous usage and error data, which you can turn off."

#How to get it

The User Guide and GitHub repository set out the install paths above. The product page lists three steps: start the emulator on a laptop or in CI, point the AWS SDK or CLI at the endpoint URL and credentials the emulator provides, and create resources locally to test. For coding agents, the README says to install the aws-emulator skill and ask an agent to set up the emulator. "This needs the AWS CLI version 2.35.0 or later." The README states: "This repository does not take PRs." AWS asks people to report bugs and fidelity gaps in GitHub Issues.

#How does it compare?

On the product page, AWS contrasts the emulator with mocks: "A mock returns whatever you tell it to. The emulator runs the API itself, including validation, errors and state that carries across calls."

SiliconANGLE reported that "there are some existing third-party AWS emulators that developers can use," but that "those services cover only a small fraction of AWS’ sprawling catalog of cloud services and quickly drift out of sync as those services evolve." AWS does not name those tools.

Related coverage includes GitHub Copilot Fusion's agentic workflows and Google CodeMender's sandbox scan modes. Our guide to controlling what AI coding agents can reach on a Mac covers a related local-network question.

Our analysis: AWS has published a local endpoint for SDK and CLI calls, with fidelity limits and a public gap list, which can shrink early test loops for coding agents. It is not a stand-in for a real account, production traffic or security testing. The claim that no human wrote or reviewed the code comes from SiliconANGLE's report of Goldberg's blog post, not from AWS's What's New post or User Guide.

#What is still unclear?

AWS's own pages do not state how many services or APIs the emulator supports. Coverage has to be checked per service in the fidelity scores published with each release. The User Guide says Region-specific behavior is not reflected, and production use is explicitly unsupported.