floci
Floci is a free, open-source local AWS emulator that lets you develop and test against AWS services without a cloud account or authentication tokens. It runs 68 AWS services in Docker and starts in milliseconds, making it practical for local development and CI pipelines.
Key facts
Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.
| Field | Value |
|---|---|
| Repository | floci-io/floci |
| Owner | floci-io |
| Primary language | Java |
| License | MIT — OSI-approved |
| Stars | 15.6k |
| Forks | 1.6k |
| Open issues | 118 |
| Latest release | 1.5.31 (2026-07-07) |
| Last updated | 2026-07-07 |
| Source | https://github.com/floci-io/floci |
What floci is
Written in Java, Floci emulates AWS APIs on port 4566 using a JAX-RS/Vert.x HTTP router. Stateless services run in-process; container-backed services (Lambda, RDS, ECS, EKS, Neptune, etc.) use real Docker execution. Supports configurable storage backends (in-memory, persistent, WAL, hybrid).
Get the floci source
Clone the repository and explore it locally.
git clone https://github.com/floci-io/floci.gitcd floci# follow the project's README for install & configurationNeed it deployed, integrated, or customized instead? DEV.co ships production installs.
Best use cases
Implementation considerations
- Start with official floci-cli (docker compose up or 'floci start') for ease; manually export AWS_ENDPOINT_URL, AWS_DEFAULT_REGION, and dummy credentials (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY).
- Storage backend (memory, persistent, hybrid, WAL) must be chosen upfront based on durability needs; in-memory is fastest, persistent requires disk I/O.
- Real Docker services (Lambda, RDS, Neptune, ECS, EKS) require Docker Engine running; ensure sufficient resources (CPU, memory, disk) for test workload.
- IAM and SigV4 auth are mocked; requests using any non-empty credentials succeed. Real security validation does not occur; treat as unsafe for multi-tenant or sensitive-credential scenarios.
- Container-backed services (Lambda, RDS, CodeBuild) use Docker API; network isolation and resource limits depend on Docker daemon configuration.
When to avoid it — and what to weigh
- Need production-grade AWS compatibility guarantees — Floci is an emulator, not AWS itself. Operation-level coverage varies; unverified parity with newer AWS API versions or edge cases may diverge.
- Require commercial SLA or vendor support — Floci is MIT-licensed open source with no formal support, SLA, or enterprise tier. Bug fixes and feature additions depend on community contributions and maintainer availability.
- Operating at scale with many concurrent services — Real Docker containers for Lambda, RDS, ECS, etc. can become resource-intensive. Scalability for 100s of concurrent services or stress testing not documented.
- Migrating from proprietary LocalStack Pro — Some advanced features (e.g., cross-account IAM, advanced mocking) may not be present; migration effort depends on LocalStack Pro usage patterns.
License & commercial use
MIT License (OSI-compliant, permissive). Allows commercial and private use without restriction, provided license and copyright notice are retained.
MIT is a permissive OSI license. Commercial use—including embedding Floci in paid products or using it for commercial development—is permitted without license fees. No commercial support or SLA included; support comes from community and self-service documentation.
DEV.co evaluation signals
Editorial assessment — not user reviews. Directional, with an explicit confidence level.
| Signal | Assessment |
|---|---|
| Maintenance | Active |
| Documentation | Adequate |
| License clarity | Clear |
| Deployment complexity | Low |
| DEV.co fit | Strong |
| Assessment confidence | High |
Floci is designed for development and test environments, not production. IAM and credential validation are mocked; any non-empty credentials accepted. No TLS enforcement; HTTP-only on port 4566. Docker access required; containers run with inherited Docker daemon privileges. Not suitable for handling real secrets or sensitive credentials in development workflows. For CI/CD, isolate test containers and scrub credentials from logs.
Alternatives to consider
LocalStack Pro / Enterprise
Advanced mocking, cross-account IAM, commercial support, and SLA. Requires auth token and paid subscription. Still maintained but no Community Edition as of March 2026.
AWS SAM (Serverless Application Model) + moto
Lightweight, pure-Python mocking library for Lambda, S3, DynamoDB. No Docker required. Narrower service coverage (~30 services); no container-backed workloads (RDS, ECS, EKS).
Testcontainers (raw Docker)
Spin up real AWS service Docker images (e.g., localstack, moto server, dynamodb-local). Full control; requires manual orchestration. No unified endpoint or IaC support.
Build on floci with DEV.co software developers
Start with 'docker compose up' or the floci-cli. Check the services table to confirm coverage for your workload, and review storage backend options for your durability needs.
Talk to DEV.coRelated open-source tools
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Related on DEV.co
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floci FAQ
Do I need an AWS account to use Floci?
Is Floci a drop-in replacement for LocalStack Community?
Can I use Floci in production?
What happens to my data if Floci restarts?
Custom software development services
DEV.co is a software development agency delivering custom software development services to companies building on open source. Our software developers and web developers design, integrate, and ship production systems — spanning web development, APIs, AI, data, and cloud. If floci is part of your open-source devops roadmap, our team can implement, customize, migrate, and maintain it.
Ready to emulate AWS locally?
Start with 'docker compose up' or the floci-cli. Check the services table to confirm coverage for your workload, and review storage backend options for your durability needs.