s2.dev (YC Fall 2025)

TL;DR: s2.dev is a Y Combinator Fall 2025 startup API for unlimited, durable, real-time streams, currently active with a team of 5.

API for unlimited, durable, real-time streams

YC ID
30935
YC Batch
Fall 2025
Status
Active
Team size
5
Industry
B2B, Infrastructure
Tags
Developer Tools, API, Infrastructure
YC profile
https://www.ycombinator.com/companies/s2-dev

Last verified:

S2 is an API for durable streams. We make working with streaming data dead simple and reliable. The more we worked on data systems, the more we felt like there was a missing building block. The seamless experience of object storage simply did not exist for durable streams – so we set out to fix that! S2 reimagines streams as an unlimited and access-controlled web resource. Like if Kafka and S3 had a baby. - Building agents? Use granular streams to persist context in real time, make workflows auditable, and coordinate between agents. - Publishing fast-moving data? Streams support high fanout and can be accessed directly over the internet, so they are a great fit for broadcasting real-time feeds. - Sandboxing? Emit to per-instance streams, and read history or live events just as easily. - L…

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Frequently asked questions

Is s2.dev a YC (Y Combinator) company?

Yes. s2.dev was funded by Y Combinator in the Fall 2025 batch. API for unlimited, durable, real-time streams

What does s2.dev do?

S2 is an API for durable streams. We make working with streaming data dead simple and reliable. The more we worked on data systems, the more we felt like there was a missing building block. The seamless experience of object storage simply did not exist for durable streams – so we set out to fix that! S2 reimagines str…

What YC batch was s2.dev in?

s2.dev was part of Y Combinator's Fall 2025 batch.

How big is s2.dev?

s2.dev has a team of 5 people according to Y Combinator's directory.

Is s2.dev still active?

s2.dev is currently listed as Active with a team of 5 in Y Combinator's directory.

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