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Floci is a natively compiled, open-source local AWS emulator (announced…

Brief

Floci is a natively compiled, open-source local AWS emulator (announced 2026-05-11) shipped as a 90 MB Docker image that claims to emulate 46 AWS services, boot in ~24 ms, and idle at ~13 MiB RAM. Point your AWS SDK at localhost:4566 with no auth required; repo link provided in the thread.

Source evidence

Wait... someone just open-sourced the entire AWS cloud in a 90MB Docker image 🤯

Every local AWS emulator before this needed gigabytes of RAM.

Cold starts took seconds just to test one single function, and free tiers are increasingly getting locked down.

Meet Floci.

It's a natively compiled emulator that completely rethinks local cloud testing.

What runs locally with zero dependencies?

→ Storage & Databases: S3, DynamoDB, RDS, ElastiCache
→ Compute: Lambda, EC2, ECS, EKS
→ Events & Messaging: SQS, SNS, EventBridge, Kinesis
→ Security & Auth: IAM, KMS, Cognito, STS

It handles 46 AWS services natively, boots in ~24 milliseconds, and idles at just 13 MiB of memory.

The average Chrome tab uses 15x more than that!

Point your standard AWS SDK at localhost:4566 and your existing scripts work untouched.

No auth tokens, no feature gates, and tests finish before legacy emulators even pull their image.

It's 100% free and open-source.

Repo link in 🧵↓