SECURITY Signal 214
LaunchDarkly is now available on the Vercel Marketplace
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LaunchDarkly feature flag integration is now available through the Vercel Marketplace, letting developers add flags with minimal setup.
The integration removes much of the manual configuration needed to connect LaunchDarkly to a Vercel project, accelerating experimentation and safer rollouts. Engineers can view, override, and sync flags directly from the Vercel Toolbar and Global Config, keeping flag management close to the deployment workflow.
Written by elseif from the cluster below · every claim links back to a sourceThe three things worth knowing
Install the integration with `vercel install launchdarkly` and add the `@flags-sdk/launchdarkly` adapter to the project.
Flags are synchronized to Vercel Global Config and can be evaluated locally after pulling the required environment variables with `vercel env pull`.
Server-side flag evaluation in Server Components or route handlers gates new features, and missing env vars or mismatched flag keys will prevent the flag from working.
THE READ
What the cluster adds up to.
LaunchDarkly is now listed in the Vercel Marketplace, offering a pre-built adapter for the Flags SDK. This listing removes the need for developers to create their own integration code. The Vercel Toolbar gains a Flags Explorer pane for interacting with LaunchDarkly flags.
To start, run `vercel install launchdarkly` and install the `@flags-sdk/launchdarkly` package. In `flags.ts` import the adapter and declare each flag using `flag()` from `flags/next` with `adapter: ldAdapter.variation()`. The identify function must build the LDContext from cookies or headers without making network calls. Required environment variables, LAUNCHDARKLY_CLIENT_SIDE_ID, LAUNCHDARKLY_PROJECT_SLUG, and EXPERIMENTATION_CONFIG, are fetched locally with `vercel env pull` or set manually from the LaunchDarkly dashboard.
If any of the three environment variables are missing or incorrect, the adapter cannot initialize and flag evaluation will fail. Flag keys declared in code must exactly match keys that exist in the LaunchDarkly project; a mismatch results in an undefined flag value. The identify function should avoid network calls, otherwise the local evaluation promise is broken.
Once configured, flags are synced to Vercel Global Config and can be evaluated in Server Components or route handlers by awaiting the flag value. Teams can target releases by user, attribute, or segment, run experiments with attached metrics, and roll back using a kill switch. The Flags Explorer in the Vercel Toolbar lets developers view current flag states and override them without redeploying. This tight coupling between feature flag service and deployment platform streamlines experimentation and risk mitigation.
Written by elseif from the cluster below · checked for specifics the sources never containedTHE CLUSTER