## Summary
Realtime streams (AI-agent token streaming and run streams) now default
to v2 for self-hosters, backed by a bundled [s2-lite](https://s2.dev)
service. Self-hosting previously shipped no S2 configuration, so streams
ran on the Redis-backed v1 path and there were no docs for wiring up v2.
Both the Docker Compose stack and the Helm chart now provision s2-lite
with persistent storage and set the stream env vars out of the box.
## What's included
- **Docker Compose**: a persistent `s2` service (s2-lite), a basin init
spec, and the `REALTIME_STREAMS_S2_*` plus
`REALTIME_STREAMS_DEFAULT_VERSION=v2` env on the webapp. `.env.example`
documents the v1 fallback and hosted-S2 options.
- **Helm**: an `s2` StatefulSet, PVC, Service and ConfigMap (runs as the
non-root image user via `fsGroup`), an `s2` values block, and webapp env
wiring with an existing-secret path for hosted S2.
- **Docs**: the `REALTIME_STREAMS_S2_*` and
`REALTIME_STREAMS_DEFAULT_VERSION` vars in the webapp env reference,
plus a "Realtime streams" section in the Docker and Kubernetes
self-hosting guides.
## Notes
- The OSS code default stays `v1`; v2 becomes the default purely through
the self-hosting artifacts, so non-self-host deployments are unaffected.
Disabling s2, or setting the version back to `v1`, cleanly reverts to
Redis-backed v1.
- With v2 enabled, the bundled s2 service is a required dependency for
streaming: if it is down, streams error while the task itself still
runs. That is the intended trade for the better v2 path.
- You can point at a hosted S2 at s2.dev instead of the bundled server.
Matt Aitken
a682f1d171