AWS Emulator: Run AWS Locally, Free and Open Source | LocalEmu
localemu.cloud
LocalEmu is a free, open-source AWS emulator. Run 132 AWS services locally with one pip install: no account, no token, no telemetry. The drop-in LocalStack alternative for the AWS CLI, boto3, Terraform and CDK.

I maintain LocalEmu, a free and open-source (Apache 2.0) AWS emulator. It started as a fork of the archived LocalStack Community edition. The goal is to keep a genuinely free, open local AWS emulator alive and maintained.

What it does:

  • Emulates 132 AWS services on a single endpoint (localhost:4566)
  • Pure-Python core, with real Docker engines for Lambda, EC2, RDS, ECS, EKS, and OpenSearch
  • Point your existing AWS CLI, boto3, Terraform, CDK, or Pulumi at it, zero config
  • No account, no auth token, no telemetry. Persistent state across restarts
  • Optional fidelity knobs: IAM policy enforcement, throttling, latency injection, Lambda cold starts

Why I built it: kill the multi-minute deploy loop, drop the dev/test AWS bill to zero, and stop keeping real credentials on dev machines.

It’s for fast local dev, testing, and learning, not production, and not bit-for-bit parity with the real cloud.

Repo: https://github.com/localemu/localemu Site: https://localemu.cloud/

Happy to answer questions, and feedback is very welcome.

    • Hexarei@beehaw.org
      3·
      2 months ago

      If the project itself is vibe coded, the author is doing a good job of hiding it. There’s some slight lean towards claude-like speak, (“real behavior” and the way some of the readme sounds) but the commit style and comments and such don’t immediately trigger the obvious LLM alarms in my head.

      That website is definitely vibe coded though. I’ve seen enough one-shot websites from LLMs while playing around with them to immediately notice the AI website style lol

  • jtrek@startrek.website
    5·
    2 months ago

    Interesting. We used the free localstack at a previous job and it kind of sucked. Mostly we were trying to do S3, and it made adding a lot of files kind of painful. Looks like this has better support for “I need to load a bunch of files into S3 when I start working”.

    Can you map a directory and subfolders to S3 with this, or so you need to make calls to “upload” everything?

    • nullroute@programming.devOP
      41·
      2 months ago

      Thanks for trying LocalEmu :). Yes, you can map a directory without scripting per-file uploads.

      aws s3 sync ./mydir s3://mybucket/ works against LocalEmu out of the box (or awsemu s3 sync with the bundled zero-config CLI). For “always populated on start”, drop a one-line script in /etc/localemu/init/ready.d/ and it runs on every boot:

      docker run --rm -d -p 4566:4566 \
  -v $PWD/fixtures:/fixtures:ro \
  -v $PWD/init:/etc/localemu/init/ready.d:ro \
  -e DASHBOARD_API_OPEN=1 localemu/localemu

      Where init/ready.d/seed.sh does awsemu s3 sync /fixtures s3://mybucket/. Or PERSISTENCE=1 if you’d rather load once and have it stick.

      LocalStack inspired a lot of this, we’re the free open-source continuation.