Quarkus

If you’ve been following AWS local development tooling, you probably noticed that LocalStack Community Edition started requiring auth tokens and moved features behind paid tiers in early 2026. That left a real gap for developers who just want to run AWS services locally. No account, no quotas, no strings attached. That’s exactly why I built Floci. What is Floci? Floci is a free, open-source local AWS emulator written in Java with Quarkus and compiled to a native binary via GraalVM. It runs on port 4566, the same port as LocalStack, so switching requires changing just one environment variable. ...

In late 2019, the Java world was buzzing with a new name: Quarkus. Promising “Supersonic Subatomic Java,” it aimed to fix the long startup times and heavy memory usage that had plagued traditional Java applications in the age of containers and serverless. At that time, Quarkus was still in its BETA phase, but the vision was clear. It wasn’t just another framework; it was a fundamental rethink of how we build Java applications for Kubernetes. ...

Floci is a local AWS service emulator — a drop-in replacement for LocalStack’s community edition that requires no auth token, has no usage limits, and is MIT-licensed. The name comes from cirrocumulus floccus, a small, fluffy cloud formation. That’s the design goal: minimal, lightweight, and always free. GitHub: github.com/floci-io/floci Native Floci vs LocalStack Metric Native Floci LocalStack Advantage Startup Time ~24 ms ~3,300 ms 138× faster Idle Memory ~13 MiB ~143 MiB 91% less Lambda Latency 2 ms avg 10 ms avg 5× faster Lambda Throughput 289 req/s 120 req/s 2.4× faster Docker Image Size ~90 MB ~1.0 GB 11× smaller Price Free Forever Auth Token Req. $0 / No Auth Supported AWS Services SSM · SQS · SNS · S3 · DynamoDB · DynamoDB Streams · Lambda · API Gateway REST · API Gateway v2 · IAM · STS · Cognito · KMS · Kinesis · Secrets Manager · CloudFormation · Step Functions · ElastiCache · RDS · MSK · EventBridge · EventBridge Scheduler · CloudWatch Logs · CloudWatch Metrics · ECS · EC2 · ACM · ECR · SES · SES v2 · OpenSearch · Athena · Glue · Data Firehose · AppConfig · AppConfigData · Bedrock Runtime · EKS ...

Local development against AWS services has always been painful. You either run real AWS (expensive, slow, requires an internet connection) or use an emulator. For years, LocalStack was the go-to choice — until they required auth tokens and locked down their community edition in early 2026. That gap is exactly what Floci fills. Key Numbers: Native Floci vs LocalStack Metric Native Floci LocalStack Advantage Startup Time ~24 ms ~3,300 ms 138× faster Idle Memory ~13 MiB ~143 MiB 91% less Lambda Latency 2 ms avg 10 ms avg 5× faster Lambda Throughput 289 req/s 120 req/s 2.4× faster Price Free Forever Auth Token Req. $0 / No Auth What Is Floci? Floci is a free, open-source local AWS service emulator written in Java using Quarkus and compiled to a native binary via GraalVM Mandrel. It runs as a single process on port 4566 — the same port LocalStack uses — so switching requires zero changes to your existing code or tooling. ...

Talk given at JConf Dominicana — July 2019 What Is Quarkus? Quarkus is a Kubernetes-native Java stack designed for GraalVM and OpenJDK HotSpot, crafted from the best Java libraries and standards. Created by Red Hat License Apache License v2.0 Version at time of talk 1.0.0.CR2 The tagline says it all: Supersonic Subatomic Java — startup times measured in milliseconds, memory footprints measured in megabytes. GraalVM — The Engine Behind Native Compilation GraalVM is a universal virtual machine capable of running JavaScript, Python, Ruby, R, Java, all JVM-based languages, and LLVM-based languages like C and C++. ...