Floci, an MIT-Licensed AWS Emulator, Passes 30,000 Stars After LocalStack's Token Change

Floci, an MIT-licensed local AWS emulator written in Java, has passed 30,000 GitHub stars. The repository was created on February 18, 2026, and showed 30,229 stars and 3,320 forks when The Terminal checked it on November 5.

It exists because LocalStack changed how it ships. Floci's README pitches itself as the free alternative: point the AWS SDK, CLI, Terraform, CDK or OpenTofu at http://localhost:4566 and the same code runs against an emulator that needs no account.

What the Floci README claims, and what it does not measure

The README says Floci starts in about 24 ms and idles at about 13 MiB of memory. For LocalStack Community it lists about 3.3 s and 143 MiB. The Docker image is about 90 MB against about 1.0 GB, and a native binary is about 40 MB.

The page gives no method for any of these figures, so treat them as the project's own numbers.

1. Floci24 ms
2. LocalStack Community3300 ms

Source: Floci README (project-supplied, no method given), accessed 2026-11-05

The README sets out the release cadence too: stable releases on the 15th and the last day of each month, plus a nightly tag that tracks main. GitHub's releases list shows 2.2.0 on October 6, 2.3.0 on October 15 and 2.4.0 on October 31.

What LocalStack changed in March 2026

LocalStack's own post, written by CTO and co-CEO Waldemar Hummer and COO and co-CEO Gerta Sheganaku, first appeared on December 18, 2025 and was updated on March 17, 2026. It says that beginning in March 2026 "LocalStack for AWS will be delivered as a single, unified version" at localstack/localstack.

The unified image asks for an auth token, and CI needs a separate CI token. The post says: "we cannot commit to releasing regular updates to the Community edition of LocalStack for AWS." Source code stays on GitHub but is marked inactive.

A pinned older tag still runs without a token, locally and in CI. The post's example is 4.12, and it adds that pinned versions get no backported fixes or security updates. An update to the post says the free tier is for non-commercial use only.

Floci's README goes further than that wording. It says LocalStack Community "sunset in March 2026" and that its security updates are frozen. LocalStack's post does not use the word sunset. It says it cannot commit to updates, and the post's own pricing section lists no prices.

That gap matters to anyone whose pipeline pulls latest. LocalStack tells those users to change before the switch, and Floci says migration is mostly an image swap, with LocalStack environment variables translated automatically.

Where Floci stops being AWS

The same README is candid about what is not real. Several services run in actual Docker containers, among them Lambda, RDS, ElastiCache, MSK and EKS, which means Floci needs access to the Docker socket. Others are stand-ins.

Service	What the README says it does
Textract	In-process stub
Transcribe	Jobs complete immediately, no audio processed
Bedrock Runtime	Returns dummy responses
FIS	Control-plane simulation, injects no faults
Application Auto Scaling	Policies stored but inert

Two more details are worth knowing before it goes anywhere near a shared network. Any non-empty credentials work unless stricter auth is switched on, and S3 auth enforcement defaults to false. The web console pulls and starts a sidecar container on the first request.

For tests that only need S3, SQS, DynamoDB and IAM to answer correctly, that is a fair trade. For a test that claims to prove an IAM policy denies something, an emulator that accepts any credentials will pass for the wrong reason.

The README counted 138 open issues and 50 open pull requests. GitHub's API reported 188 open issues, a figure that counts pull requests as issues. The top contributor by commits is the account hectorvent with 626, followed by pgermosen with 416.

The Terminal has also covered an emulator for Databricks APIs and a firmware simulator from a Y Combinator company.

Floci's next stable release is due on November 15, going by the cadence in its README.