The Java and Python SDKs now support the same real-time flag evaluation architecture previously available in Go and C#.

DataStream

Both SDKs now open a persistent WebSocket connection to Schematic on startup. When a flag check comes in, the SDK pulls the company data once, subscribes to future updates for that company-flag pair, and resolves all subsequent checks locally without an API call. Plan changes, override updates, and usage changes are pushed to the SDK in real time. Read more about DataStream and cross-platform SDK features.

Replicator

Both SDKs now support Replicator, which replicates all flag, company, and user data into your own infrastructure via a Schematic-provided container backed by Redis. Flag checks never leave your network. Updates propagate automatically, and your application continues operating from the local cache if Schematic is unreachable.

Optimistic Metric Updates

When the SDK processes a track event tied to a metered feature, it now optimistically increments the local usage count before the server confirms. Flag checks that depend on usage limits reflect the change immediately instead of waiting for the round trip. This closes a real gap for hard limits: if a customer has 3 of 5 API calls remaining and makes a request, the SDK knows they have 2 left without waiting for server confirmation.

SDK support matrix for DataStream and Replicator is now: Go, C#, Java, Python. Node.js is coming soon. See the full SDK support table for details.