What is this?
Floci is a free, open-source local AWS emulator: it serves AWS-compatible APIs — S3, SQS, DynamoDB, Lambda, ECS and many more — from your own machine for development, testing, and CI, with no cloud account, auth token, or paid feature gates.
Floci is a free, open-source local AWS emulator: it serves AWS-compatible APIs — S3, SQS, DynamoDB, Lambda, ECS and many more — from your own machine for development, testing, and CI, with no cloud account, auth token, or paid feature gates.Is Floci a library I import, or a service I run?It's a service you run: a Docker container (or a ~40 MB native binary) that listens on port 4566 and speaks the AWS APIs. You point your existing AWS SDK, CLI, Terraform or test suite at it — nothing gets imported into your code.
It's a service you run: a Docker container (or a ~40 MB native binary) that listens on port 4566 and speaks the AWS APIs. You point your existing AWS SDK, CLI, Terraform or test suite at it — nothing gets imported into your code.How do I get it running?Fastest path: install the official floci CLI, start it, and export the AWS environment variables it prints. Prefer plain Docker? Add the image to a compose.yaml, run docker compose up, and configure the AWS environment manually.
Fastest path: install the official floci CLI, start it, and export the AWS environment variables it prints. Prefer plain Docker? Add the image to a compose.yaml, run docker compose up, and configure the AWS environment manually.Do I need an AWS account or an auth token to use it?No AWS account, no auth token, no feature gates — any non-empty credentials work unless you enable stricter service-specific auth checks. You do need Docker, which also powers the container-backed services.
No AWS account, no auth token, no feature gates — any non-empty credentials work unless you enable stricter service-specific auth checks. You do need Docker, which also powers the container-backed services.Does it really cover every AWS service, or are some faked?Coverage is wide — from S3, SQS, DynamoDB and Lambda through ECS, EKS, RDS, Cognito and API Gateway v2 to Athena, EMR and Bedrock. Most services run in-process, and a few, like Bedrock Runtime, are stubs that return dummy responses.
Coverage is wide — from S3, SQS, DynamoDB and Lambda through ECS, EKS, RDS, Cognito and API Gateway v2 to Athena, EMR and Bedrock. Most services run in-process, and a few, like Bedrock Runtime, are stubs that return dummy responses.Is this built for my laptop, or for CI pipelines too?Both — it targets local development and test pipelines. The native image starts in about 24 ms and idles at ~13 MiB, and the Docker image is ~90 MB, so booting it per test run is practical.
Both — it targets local development and test pipelines. The native image starts in about 24 ms and idles at ~13 MiB, and the Docker image is ~90 MB, so booting it per test run is practical.Is it actually free, or is there a catch in the license?MIT — genuinely free for any use, commercial included. The README contrasts this directly with LocalStack's restricted license.
MIT — genuinely free for any use, commercial included. The README contrasts this directly with LocalStack's restricted license.When I invoke a Lambda function or create an RDS database, is it the real thing?For fidelity-critical services, yes: Lambda, RDS (PostgreSQL, MySQL, MariaDB), Neptune, ElastiCache, MSK, ECS, EC2, EKS, OpenSearch and CodeBuild run in real Docker containers. Lighter services like S3, SQS and DynamoDB are emulated in-process.
For fidelity-critical services, yes: Lambda, RDS (PostgreSQL, MySQL, MariaDB), Neptune, ElastiCache, MSK, ECS, EC2, EKS, OpenSearch and CodeBuild run in real Docker containers. Lighter services like S3, SQS and DynamoDB are emulated in-process.Why did the author build this instead of using LocalStack?LocalStack's community edition sunset in March 2026, began requiring auth tokens and froze security updates. Floci was built as the no-strings-attached alternative, claiming ~24 ms startup versus ~3.3 s and a ~90 MB image versus ~1 GB.
LocalStack's community edition sunset in March 2026, began requiring auth tokens and froze security updates. Floci was built as the no-strings-attached alternative, claiming ~24 ms startup versus ~3.3 s and a ~90 MB image versus ~1 GB.Can I point Terraform at it?Yes — Terraform provisions AWS-shaped resources locally through the standard HashiCorp AWS provider, and Floci can even serve an emulated S3 backend for Terraform state. CDK and OpenTofu workflows work too.
Yes — Terraform provisions AWS-shaped resources locally through the standard HashiCorp AWS provider, and Floci can even serve an emulated S3 backend for Terraform state. CDK and OpenTofu workflows work too.If I restart the container, do I lose everything?Not necessarily — storage is configurable: pick in-memory, persistent, hybrid, or write-ahead-log mode depending on how durable you need data between runs.
Not necessarily — storage is configurable: pick in-memory, persistent, hybrid, or write-ahead-log mode depending on how durable you need data between runs.What are similar projects?ministack, localstack, full-stack-data-engineering, forge, awesome-aws, infracost, encore, semaphore
ministack, localstack, full-stack-data-engineering, forge, awesome-aws, infracost, encore, semaphoreWhich topics is it in?ec2, ecs, terraform, infrastructure-as-code, emulator, s3, ci-cd, aws, containers, ci, testing, docker-compose
ec2, ecs, terraform, infrastructure-as-code, emulator, s3, ci-cd, aws, containers, ci, testing, docker-compose