Flags SDK + OpenFeature
A minimal Next.js App Router example with two server-evaluated flags, adapted from the OpenFeature example. It uses OpenFeature's built-in InMemoryProvider so no provider account or credentials are needed.
The Deploy button copies only this folder and installs published packages using the standard Next.js build command.
Setup
Copy .env.example to .env.local and set FLAGS_SECRET to a random secret:
The home page uses evaluate() to evaluate welcome_message and show_banner. Change the greeting or switch the banner's defaultVariant from on to off in flags.ts, then refresh the page. Every visitor uses the same demo-user targeting key; replace identify to add user targeting.
The in-memory provider is for demonstration. Replace it with your OpenFeature provider in flags.ts for production. The adapter waits for provider initialization before evaluating flags.
Flags Explorer
This example has no upstream provider service. Its discovery endpoint at /.well-known/vercel/flags uses getProviderData from flags/next to expose the definitions declared in flags.ts, protected by FLAGS_SECRET. The page reports the evaluated values to the toolbar.
The Vercel Toolbar is included during local development. Link this folder with vercel link and add the same FLAGS_SECRET to the linked project's Development environment. Use a regular environment variable (Config), rather than a Secret. Alternatively, pull an existing value with vercel env pull .env.local.
Sign in to the toolbar and open Flags Explorer to override the greeting or banner for your session without changing the in-memory provider configuration. Vercel injects the toolbar on preview deployments when enabled in project settings; configure a matching FLAGS_SECRET for that environment.
Run as a standalone project
Copy this folder, or use the Deploy button above. From the copied folder:
Open http://localhost:3000. For a production build, run pnpm build and pnpm start. Use Node.js 22 or newer.
Run inside the Flags SDK repository
Configure examples/providers/openfeature/.env.local as above. From the repository root:
The root pnpm-workspace.yaml overrides flags and @flags-sdk/openfeature with local workspace packages. Explicit dependencies in the root turbo.json build them before starting the example. To build only this example and its dependencies:
When cloned independently, the root overrides are absent and the versions in package.json resolve from npm. No shared workspace configuration is required.
