Browser client.

@splitch/sdk/browser provides a static-context browser client. It holds one Evaluation Context for its lifetime, fetches Precomputed Evaluations once, and makes synchronous Flag reads with no per-read network request.

import { createSplitchBrowserClient } from "@splitch/sdk/browser";

const splitch = createSplitchBrowserClient({
  clientKey: "pk_...",
  context: { targetingKey: user.id },
  revalidateMs: 60_000,
});

await splitch.init();

const enabled = splitch.evaluate("new-checkout", false);
const details = splitch.evaluateDetails("new-checkout", false);
await splitch.flush();

The browser client accepts a public Client Key. Secret credentials throw at construction. Reading before init() resolves throws SDK_NOT_INITIALIZED.

The first local read of a Flag redeems its Exposure Ticket and queues one Exposure. flush() acknowledges delivery. An unknown Flag returns the caller's Default Variant with reason: "ERROR", FLAG_NOT_FOUND, and a loud log.

Bootstrap and revalidation

Pass a server evaluateAll result as bootstrap to make reads available immediately and prevent an initial fetch. See evaluateAll and bootstrap for the server and browser boundary.

The client revalidates with If-None-Match every 60 seconds by default. Set revalidateMs to 0 to disable polling. A 304 keeps the current payload; a changed response swaps it atomically and notifies subscribers only for changed Flags.

Failed revalidation logs on every attempt and keeps serving the last-known-good values as STALE with PROVIDER_NOT_READY until recovery. Call close() to stop polling.

Exposure delivery

flush() drains the Exposure queue. Retryable delivery failures make at most three automatic attempts. A non-retryable 4xx stops automatic delivery after its first attempt. Both terminal paths log loudly, retain the items, and leave them available for an explicit flush().