Floci: A Lightweight, Open-Source Local AWS Emulator for Developers
Floci is a free, MIT-licensed local AWS emulator. Run AWS services offline with Docker—no account, no auth tokens, no feature gates. A practical LocalStack alternative for testing and development.
What is Floci?
Floci is a free, open-source tool that lets you run AWS services locally on your machine. No cloud account. No paywalls. No complex setup. Just docker compose up and start building.
Named after the floccus cloud formation—those fluffy, popcorn-like clouds you see on a clear day—Floci brings the same lightness to local AWS development. It's designed for developers who need a reliable, offline environment to test applications against real AWS APIs, without depending on remote infrastructure or subscription tiers.
Why choose Floci?
With LocalStack's Community Edition sunsetting in March 2026—requiring auth tokens and halting security updates—many teams are looking for a straightforward alternative. Floci fills that gap with:
- Zero friction: No sign-up, no tokens, no feature gating
- Tiny footprint: ~90 MB Docker image, ~13 MiB idle memory, ~24 ms startup
- Full MIT license: Use, modify, and deploy without restrictions
- Drop-in compatibility: Works on port 4566 with existing AWS SDKs, CLI commands, and LocalStack init scripts
- Broad service support: From S3 and DynamoDB to ECS, EKS, RDS, Cognito, Kinesis, and more
Key features at a glance
- Core services: S3 (with Object Lock), DynamoDB (with Streams), IAM, STS, KMS, Kinesis
- Data & analytics: Athena (via DuckDB), Glue Catalog, Data Firehose, ElastiCache (Redis + IAM auth)
- Compute & orchestration: EC2 (real Docker instances), ECS, EKS (mock + k3s), Lambda, Auto Scaling
- DevOps tooling: CodeBuild, CodeDeploy, SSM Run Command, Transfer Family (SFTP)
- Messaging & streaming: MSK (Kafka/Redpanda), Kinesis fan-out, SQS/SNS compatible endpoints
- Developer experience: Native binary option (~40 MB), persistent storage mode, debug logging, health endpoints
Migrating from LocalStack? It's simple.
Floci is built as a direct replacement for LocalStack Community. Update your docker-compose.yml:
# Before
image: localstack/localstack
# After
image: floci/floci:latest
Environment variables map automatically (LOCALSTACK_HOST → FLOCI_HOSTNAME, PERSISTENCE=1 → FLOCI_STORAGE_MODE=persistent). Init scripts under /etc/localstack/init/ run unchanged. For scripts using the AWS CLI or boto3, use the -compat image variant.
Get started in minutes
- Pull the image:
docker pull floci/floci:latest - Add to your
docker-compose.yml - Point your AWS SDK/CLI to
http://localhost:4566 - Start coding—offline, securely, without waiting for cloud resources
Join the conversation
Floci is community-driven. Share feedback, ask questions, or propose ideas on GitHub Discussions or join the Slack workspace. Whether you're debugging a CloudFormation template, testing IAM policies, or prototyping a serverless workflow—your input helps shape the tool.
No account. No gates. Just local AWS that works.
floci-io
