Floci lets you run AWS, Azure, GCP, and OCI locally in 24 milliseconds
Floci: Locally emulating any cloud service
Floci is a set of standalone MIT-licensed binaries that emulate AWS, Azure, GCP, and OCI cloud services on your machine. It starts in 24 ms, idles at 13 MiB, and requires no credentials or accounts. With 119 AWS services, plus Azure, GCP, and OCI emulators, it provides a fast, safe loop for developers and AI coding agents to build and test against real engines like Lambda, RDS, and Redis without risking a cloud bill.
Coding agents write cloud code faster than ever, but they can't safely run it against a real account.
- huffer
I just spilled my coffee; sorry for the trivial remark, but the name means 'pubic hairs' in Romanian. Apologies.. I thought it's better for you to know and ignore than not to (not quite a big population target for you, I imagine, anyway).
- thegagne
The cool part of this is it’s an example of what’s possible with a community of users armed with AI.
Many users, (myself included), had need to test cloud stuff locally, but had no tool to do so. Localstack exists, but it started rug pulling the free tier and they didn’t support all the features.
Meanwhile, Floci makes it easy to write your own cloud compatible test suite, then implement the feature to match. I was able to get a good enough coverage on a few features created in a weekend on the $20 tier of Claude to make it useful to me, then others picked up the work to round it out.
It’s really cool to see it grow.
- bensyverson
I've looked into developing "digital twins" of APIs that I rely on, similar to the StrongDM pattern, but the models talk me out of it every time. The rationale is that there could be subtle differences or drift between the behavior of the real service and the mocked API. So you may think you're on solid ground, but once you switch to prod, you could see show-stopping differences.
I think if I was doing evals on the way an agent interacts with a service (e.g. Slack) the digital twin could make sense, but for rapid iteration or testing, it might not be what you want.
- catlifeonmars
Both localstack and floci live in this weird spot where for a lot of my applications, all the cloud-vendor specific stuff is abstracted out anyway. So the only time I need to touch the cloud is for testing the abstractions and do end to end testing. The abstractions can be tested against real cloud APIs as it is generally cheap to do and provides the highest fidelity results. End to end testing includes testing against a production-like environment, so again, more bang for your buck to just test against the cloud.
I’ve definitely reached for these local cloud tools from time to time, but in a well-architected piece of software, you aren’t getting that much value from them. Either you don’t have a hard cloud dependency, or you want a high fidelity test of a specific cloud dependency.
- microflash
Been using it for a while to run integration tests with Testcontainers [1]. It's very good and much more lightweight than Localstack.