LaunchDarkly is now available on the Vercel Marketplace, allowing you to quickly get started with feature flags without additional setup. You can:
Sync flags into Global Config and evaluate them locally
Target releases by user, attribute, or segment
Run experiments with metrics, and roll back with a kill switch
View and override flags from the Vercel Toolbar with the Flags Explorer
To get started, run vercel install launchdarkly, add the @flags-sdk/launchdarkly adapter, and declare a flag with the Flags SDK:
import { flag } from "flags/next";import { ldAdapter, type LDContext } from "@flags-sdk/launchdarkly";
export const exampleFlag = flag<boolean, LDContext>({ key: "example-flag", identify: () => ({ key: "user-123" }), adapter: ldAdapter.variation(),});Feature flag declared with the LaunchDarkly adapter
Using a coding agent? Hand it this prompt:
Set up LaunchDarkly feature flags in this project using Vercel's Flags SDK. Reference: https://flags-sdk.dev/providers/launchdarkly The project connects to LaunchDarkly through the Vercel Marketplace integration. The adapter reads LAUNCHDARKLY_CLIENT_SIDE_ID, LAUNCHDARKLY_PROJECT_SLUG, and EXPERIMENTATION_CONFIG from the environment. Run vercel env pull to fetch them locally, and set any that are missing using values from the LaunchDarkly dashboard. Install @flags-sdk/launchdarkly. Declare each flag in flags.ts using flag() from flags/next with adapter: ldAdapter.variation(), and an identify function that builds the LDContext from cookies or headers without making network calls. Flag keys must match flags that exist in LaunchDarkly. Evaluate flags server-side by awaiting them in a Server Component or route handler, and gate the new feature behind one.
Add LaunchDarkly from the Vercel Marketplace, or read the adapter docs.
