Install.

Add @splitch/sdk and get one Flag resolving.

npm install @splitch/sdk

ESM only. Node 20 or newer, browsers, and edge runtimes. zod is the sole dependency.

Hello world

Paste the keyMaterial field from splitch client-key get (a pk_… value). The response's keyId (ck_…) identifies the key; it is not the credential.

import { createSplitchClient } from "@splitch/sdk";

const splitch = createSplitchClient({ clientKey: "pk_..." });

const variant = await splitch.evaluate("new-checkout", {
  targetingKey: user.id,
  idempotencyKey: crypto.randomUUID(),
  defaultValue: false,
});

That is one HTTP call. There is no local config file to sync and no background poller: the resolution and the Exposure it records happen in the same round-trip.

To create the App, Environment, and Flag this needs, run the platform quickstart first.