Floci is a new open-source project that lets developers run entire cloud stacks locally, on their laptops, without needing a real cloud account. The project, described as “Locally emulating any cloud service,” promises to replace LocalStack with a faster, credential-free alternative for AWS, Azure, GCP, and Oracle Cloud Infrastructure (OCI).
The core pitch is simple: instead of spinning up a real server in the cloud, you run a local binary that mimics the behavior of Amazon S3, Azure Blob Storage, Google Cloud Storage, or Oracle Object Storage. The emulators are standalone binaries released under the MIT license, meaning anyone can fork them, embed them, or extend them without hitting any enterprise feature flags.
What Each Emulator Covers
AWS support includes 119 services, running on port 4566 with a native binary. The list covers S3, Lambda, RDS, Redis, and Kafka. Azure covers Blob, Queue, Table, Functions, App Config, Key Vault, Event Hubs, and Service Bus, all on one port. GCP supports GCS, Pub/Sub, Firestore, Cloud Run, Cloud SQL, GKE, and more, with 25 services on one port. OCI covers Object Storage, Identity, Queue, Streaming, KMS, Vault, and Functions, with all 8 services on one port.
Each emulator is a drop-in replacement for LocalStack, sharing the same port 4566. That means teams switching from LocalStack can do so with zero code changes.
Why Developers Need This
Modern development workflows often involve AI agents that write cloud code. These agents can’t safely run their code against a real account — they might leak secrets, trigger bills, or overwrite production data. Floci offers a local cloud that agents can point at instead. The agents connect with throwaway keys, so there are no real cloud secrets in their context or sandbox. Nothing can be exfiltrated, and nothing gets billed.
The project also addresses a specific problem with LocalStack. LocalStack started requiring an auth token in March 2026. Floci never will.
How Fast Is It?
Floci starts in 24 milliseconds and idles at 13 megabytes. It is compiled with GraalVM Mandrel, which helps explain those low numbers. The project claims 100% protocol fidelity for Lambda, RDS, Redis, and Kafka — meaning the local versions behave exactly like their real counterparts in production.
Cold starts take 24 milliseconds. Idle memory stays at 13 megabytes. The result is that agents can spin up, test, and tear down inside the edit loop instead of waiting on round-trips to a remote account.
What Developers Can Build With It
The list of use cases is broad. Teams can apply Terraform or OpenTofu against localhost first, catching typos, drift, and bad refactors before they ever touch a real account. Students can teach cloud services with zero billing risk, since every learner runs the whole stack on their own machine with no accounts to provision or clean up.
CI pipelines benefit too. Spin up the full stack inside every pipeline job — 24 milliseconds startup adds nothing to the build, each job gets an isolated cloud, and teardown is free.
The Comparison to LocalStack
| Feature | LocalStack | Floci |
|---|---|---|
| Auth required | Yes, starting March 2026 | No |
| Port | 4566 | 4566 |
| Services | 119 | 119+ (AWS), 25+ (GCP), 8+ (OCI) |
| License | Proprietary/community edition | MIT |
| Docker image | Available | Available |
| Cold start | Not specified | 24 ms |
| Idle memory | Not specified | 13 MiB |
LocalStack has moved toward authentication, and Floci offers a drop-in replacement that skips the token entirely.
The Numbers
- Cold start: 24 milliseconds
- Idle memory: 13 megabytes
- AWS services: 119
- Azure services: Covers Blob, Queue, Table, Functions, App Config, Key Vault, Event Hubs, Service Bus
- GCP services: 25+, including GCS, Pub/Sub, Firestore, Cloud Run, Cloud SQL, GKE
- OCI services: 8+, including Object Storage, Identity, Queue, Streaming, KMS, Vault, Functions
- Port: 4566
- License: MIT
- Docker image: Available
The Verdict
Floci offers a straightforward value proposition: a local cloud emulator that requires no credentials and starts in milliseconds. For teams that have hit LocalStack’s auth requirements or want to avoid them altogether, the drop-in replacement is a compelling option.
The project’s MIT license and community-friendly approach mean it can be forked, embedded, or extended freely. Whether it becomes the default for local cloud testing remains to be seen, but the initial promise is strong.
Source material: “Floci: Locally emulating any cloud service,” floci.io.
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