This is a cross-post. I wrote a shorter, community-friendly intro to Floci for the dev.to audience. If you want the full architecture, benchmarks, and SDK compatibility numbers, read the in-depth write-up here on the site: Introducing Floci.
The short pitch: LocalStack Community Edition started requiring auth tokens and moved features behind paid tiers in early 2026. Floci fills that gap, a free, open-source, MIT-licensed AWS emulator that starts in ~24ms, idles at ~13 MiB, runs on the same port 4566, and never asks for an account, token, or quota.
It backs Lambda, RDS, ElastiCache, MSK, OpenSearch, ECS, and EKS with real Docker containers (not shallow mocks) and ships 1,850+ SDK compatibility tests across Java, JavaScript, boto3, AWS CLI, Go, and Rust.
docker run -p 4566:4566 floci/floci:latest
export AWS_ENDPOINT_URL="http://localhost:4566"
aws s3 mb s3://my-bucket
Read it on dev.to
The full community write-up lives here:
Meet Floci: a fast, free, no-strings AWS emulator (no auth token, no quotas)
Prefer the deep dive with architecture diagrams and benchmark methodology? That’s the Introducing Floci post.