S2 is a serverless API that provides unlimited, durable, real-time data streams as a cloud storage primitive, allowing append-only logs with low latency and high throughput.

Streams are directly backed by object storage, can be created and managed at arbitrary granularity, and support atomic record ordering, resumable reads, and real-time updates via standard web protocols. Access controls, SDKs for multiple languages, and a CLI are included, and there are no practical limits on number or size of streams.