Evaluate flags

const on = client.hasFeature("new_checkout", { fallback: false });
const color = client.getValue("banner_color", { fallback: "teal" });

Reads do not return a promise and do not send an exposure. refreshFlags() waits for a round trip. For Next.js, evaluate with @flagfix/node and pass exportFlagState() into FlagFixProvider so the first paint matches the server.