Nice chDB pattern: a demo mode that is not a mock. The same detection SQL and AggregatingMergeTree rollup run against ClickHouse Cloud or in an embedded chDB session, so one script hits the real queries over 250k seeded events. No account needed.
- New in chdb-node on main: chdb/durable, a pure-TypeScript control plane that keeps a chDB database durable on S3, R2 or MinIO. Lease, CAS fencing, WAL and checkpoints. The engine is injected, so importing it loads no native code.
- New in chdb-core on main: Python UDFs now accept Optional[X] and X | None type annotations. Registering a UDF that takes or returns a nullable column no longer errors out, so you can write the idiomatic signature.
- Three interchangeable query backends behind one interface: DeltaStream MCP, a ClickHouse server, and chDB. Same relation names, so the agent SQL never changes. chDB is the no-config default - seed a local mirror, run the whole demo with no cloud.
