LocalStack Is Gone. Floci vs. Moto vs. Testcontainers: Which One Replaces It?

On March 23, 2026, LocalStack archived its public GitHub repository and moved all images behind authentication. If you ran docker pull localstack/localstack in CI without a token, your pipeline broke. The immediate question — "how do I get my CI running again?" — has an answer. The longer question — "what replaces LocalStack for the next two years?" — is more interesting and less covered. This is the longer answer. What You're Actually Choosing Between Three tools have real traction as LocalStack replacements in Python stacks: Tool What it is Auth required Docker required moto Python library — mocks AWS in-process No No Floci Go service — runs as a Docker container No Yes LocalStack Community Full AWS emulator — runs as a Docker container Yes (free non-commercial token) Yes These aren't interchangeable. They operate at different layers and suit different testing scenarios. moto: The Python-First Choice Moto patches boto3 calls directly inside your test process. No Docker, no network ro