TinyS3

What it is. An S3-compatible object storage server in Java 25, for the operations listed in the S3 API reference. It runs as an embedded library, a standalone server or a Docker container.

Who it is for. Teams that need S3 storage on their own hardware, and Java developers who need a real S3 server in tests.

What is different.

Area	What is built
Conformance	ceph/s3-tests (not fails_on_aws): 596 passed, 3 failed, 4 skipped on a 4-node local cluster, recorded 2026-09-06 (status)
Storage	Reed-Solomon erasure coding across disks, background self-healing, shard encryption
Scale-out	Distributed mode, server pools and decommission
Access	AWS-style IAM: users, groups, roles, policies, access keys
Operations	Admin REST API, web console, native TLS, MCP plugin

Try it in 5 minutes. Getting started or install on Linux.

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