JavaScript SDK

The @openflagsdev/js package is the core integration point for JavaScript and TypeScript applications.

Create a client

import { createClient } from "@openflagsdev/js"

const flags = await createClient({
  apiUrl: "http://localhost:4000",
  project: "my-app",
  userId: "user_123",
  refreshIntervalMs: 60_000,
})

Evaluate a flag

if (flags.isEnabled("new_checkout")) {
  renderModernCheckout()
}

Useful capabilities

• Synchronous isEnabled() checks after the client has been created
• getAll() access when you need a full view of the current flag set
• refresh() when your app wants to refetch flag data explicitly

Best practices

• Keep flag keys stable and descriptive.
• Pass a userId when targeting matters.
• Prefer local evaluation for latency-sensitive application paths.