floci-io / floci
Light, fluffy, and always free - The AWS Local Emulator alternative
description README.md
Light, fluffy, and always free
No account. No auth token. No feature gates. Just docker compose up.
Quick Start · Features · Services · SDKs · Testcontainers · Migration · Docs
What is Floci?
Floci is a free, open-source local AWS emulator for development, testing, and CI.
It gives you AWS-shaped services on your machine without requiring a cloud account, an auth token, or paid feature gates. Point your AWS SDK, CLI, Terraform, CDK, OpenTofu, or test suite at http://localhost:4566 and keep your existing workflows.
Floci is named after floccus, the cloud formation that looks like popcorn.
Quick Start
The fastest way to run Floci is with the official CLI
floci start
Export the AWS environment variables:
eval $(floci env)
Use your existing AWS tools normally:
aws s3 mb s3://my-bucket
aws dynamodb create-table \
--table-name demo-table \
--attribute-definitions AttributeName=pk,AttributeType=S \
--key-schema AttributeName=pk,KeyType=HASH \
--billing-mode PAY_PER_REQUEST
aws dynamodb list-tables
Watch it run
This short demo shows the CLI flow: start Floci, export the local AWS environment, run standard AWS CLI commands, and stop the emulator.
https://github.com/user-attachments/assets/b55714dc-ef36-40ae-a734-cd2cadc288a8
All AWS services are available at http://localhost:4566. Any region works. Credentials can be any non-empty values unless you explicitly enable stricter service-specific auth checks.
Prefer Docker Compose?
Create a compose.yaml file:
services:
floci:
image: floci/floci:latest
ports:
- "4566:4566"
Start Floci:
docker compose up
Then configure your AWS environment manually:
export AWS_ENDPOINT_URL=http://localhost:4566
export AWS_DEFAULT_REGION=us-east-1
export AWS_ACCESS_KEY_ID=test
export AWS_SECRET_ACCESS_KEY=test
Using the old hectorvent/floci image?
Update your image name:
# Before
image: hectorvent/floci:latest
# After
image: floci/floci:latest
The old hectorvent/floci repository no longer receives updates.
Features
Local AWS without the cloud account
Run AWS-compatible services locally without an AWS account, auth token, or paid feature gates.
Real Docker where fidelity matters
Lambda, RDS, Neptune, ElastiCache, MSK, ECS, EC2, EKS, OpenSearch, and CodeBuild use real Docker-backed execution instead of shallow mocks.
Drop-in AWS compatibility
Point standard AWS clients at http://localhost:4566. Existing credentials, regions, SDKs, CLI commands, and IaC workflows stay familiar.
Fast enough for CI
The native image starts in milliseconds and keeps idle memory low, making it practical for local development and test pipelines.
Configurable persistence
Choose from in-memory, persistent, hybrid, and write-ahead log storage depending on the durability profile you need.
Why Floci?
LocalStack's community edition sunset in March 2026, requiring auth tokens and freezing security updates. Floci is the no-strings-attached alternative.
| Capability | Floci | LocalStack Community |
|---|---|---|
| Auth token required | No | Yes |
| Security updates | Yes | Frozen |
| Startup time | ~24 ms | ~3.3 s |
| Idle memory | ~13 MiB | ~143 MiB |
| Docker image size | ~90 MB | ~1.0 GB |
| License | MIT | Restricted |
| API Gateway v2 / HTTP API | Yes | No |
| Cognito | Yes | No |
| RDS, ElastiCache, MSK | Real Docker | No |
| Neptune (graph DB + Gremlin WebSocket) | Real Docker | No |
| DocumentDB (MongoDB-compatible) | Real Docker | No |
| ECS, EC2, EKS | Real Docker | No |
| CodeBuild | Real Docker execution | No |
| Native binary | ~40 MB | No |
69 AWS services. Broad coverage. Free forever.
Architecture Overview
flowchart LR
Client["AWS SDK / CLI"]
subgraph Floci ["Floci, port 4566"]
Router["HTTP Router\nJAX-RS / Vert.x"]
subgraph Stateless ["Stateless Services"]
A["SSM · SQS · SNS\nIAM · STS · KMS\nSecrets Manager · SES\nCognito · Kinesis\nEventBridge · Scheduler · AppConfig\nCloudWatch · Step Functions\nCloudFormation · ACM · Config\nAPI Gateway · AppSync · ELB v2 · Auto Scaling\nElastic Beanstalk · CodeDeploy · CodePipeline · Backup · Bedrock Runtime · Route53 · Transfer"]
end
subgraph Stateful ["Stateful Services"]
B["S3 · DynamoDB\nDynamoDB Streams"]
end
subgraph Containers ["Container Services"]
C["Lambda\nElastiCache\nRDS\nNeptune\nECS\nEC2\nMSK\nEKS\nOpenSearch\nCodeBuild"]
D["Athena -> floci-duck\nDuckDB sidecar"]
end
Router --> Stateless
Router --> Stateful
Router --> Containers
Stateless & Stateful --> Store[("StorageBackend\nmemory · hybrid · persistent · wal")]
end
Docker["Docker Engine"]
Client -->|"HTTP :4566\nAWS wire protocol"| Router
Containers -->|"Docker API\nIAM / SigV4 auth"| Docker
Supported Services
Floci supports local emulation for application services, data services, eventing, identity, infrastructure, billing, and container-backed workloads.
| Category | Services |
|---|---|
| Core app services | S3, SQS, SNS, DynamoDB, Lambda, IAM, KMS, Secrets Manager, SSM |
| Events and workflows | EventBridge, EventBridge Pipes, EventBridge Scheduler, Step Functions, CloudWatch Logs, CloudWatch Metrics |
| API and identity | API Gateway REST, API Gateway v2, AppSync, Cognito, ACM, Route53, Cloud Map |
| Containers and compute | ECS, EC2, Lightsail, EKS, ECR, CodeBuild, CodeDeploy, CodePipeline, AWS Batch, Auto Scaling, Elastic Beanstalk, ELB v2 |
| Data, analytics, and AI | Athena, Glue, EMR, Firehose, OpenSearch, S3 Vectors, Textract, Transcribe, Bedrock Runtime |
| Databases and caching | RDS, RDS Data API, Neptune, DocumentDB, MemoryDB, ElastiCache |
| Messaging and transfer | SES, Kinesis, MSK, Amazon MQ, |