refactor: migrate feature flags to LaunchDarkly

.env.example

@@ -59,6 +59,11 @@ NEXT_PUBLIC_E2B_DOMAIN=e2b.dev
 # (Required if NEXT_PUBLIC_INCLUDE_REPORT_ISSUE=1)
 # PLAIN_API_KEY=
 
+### LaunchDarkly feature flags
+### Use the SDK key for the LaunchDarkly environment selected below.
+# LAUNCHDARKLY_SDK_KEY=
+# FEATURE_FLAG_ENVIRONMENT=staging
+
 ### OTEL Configuration
 # OTEL_SERVICE_NAME=
 # OTEL_EXPORTER_OTLP_ENDPOINT=
@@ -74,7 +79,7 @@ NEXT_PUBLIC_E2B_DOMAIN=e2b.dev
 ### OPTIONAL CLIENT ENVIRONMENT VARIABLES
 ### =================================
 
-### PostHog analytics and feature flag project key
+### PostHog analytics project key
 # NEXT_PUBLIC_POSTHOG_KEY=
 
 ### PostHog source map upload (build-time only, used by @posthog/nextjs-config).

README.md

@@ -117,6 +117,16 @@ We use a layered testing strategy with Vitest and Playwright. For details on tes
 ### Environment Variables
 See [`src/lib/env.ts`](./src/lib/env.ts) for all required environment variables and their validation schemas.
 
+### Feature Flags
+Feature flags are evaluated server-side with LaunchDarkly via OpenFeature and hydrated into the dashboard client. To add a flag:
+
+1. Create it in LaunchDarkly `staging` and `production` with the same key.
+2. Add it to [`src/core/modules/feature-flags/definitions.ts`](./src/core/modules/feature-flags/definitions.ts) with a safe default value.
+3. Use `featureFlags.isEnabled(...)` on the server or `useFeatureFlag(...)` inside dashboard client components.
+4. Target users or teams in LaunchDarkly using the `user` and `team` contexts.
+
+Set `LAUNCHDARKLY_SDK_KEY` and `FEATURE_FLAG_ENVIRONMENT=staging|production` for environments that should use LaunchDarkly.
+
 ## Production Deployment
 
 This application is optimized for deployment on Vercel:

package.json

@@ -46,7 +46,10 @@
   },
   "dependencies": {
     "@hookform/resolvers": "^5.2.2",
+    "@launchdarkly/node-server-sdk": "^9.11.2",
+    "@launchdarkly/openfeature-node-server": "^1.2.0",
     "@next/env": "^16.2.7",
+    "@openfeature/server-sdk": "^1.22.0",
     "@opentelemetry/api": "^1.9.0",
     "@opentelemetry/auto-instrumentations-node": "^0.77.0",
     "@opentelemetry/exporter-logs-otlp-http": "^0.203.0",
@@ -117,7 +120,6 @@
     "pathe": "^2.0.3",
     "pino": "^9.7.0",
     "posthog-js": "^1.268.1",
-    "posthog-node": "^5.38.0",
     "react": "19.2.4",
     "react-day-picker": "^9.9.0",
     "react-dom": "19.2.4",

scripts/check-app-env.ts

@@ -34,5 +34,19 @@ const schema = appEnvSchema
       path: ['PLAIN_API_KEY'],
     }
   )
+  .refine(
+    (data) => {
+      if (data.LAUNCHDARKLY_SDK_KEY) {
+        return !!data.FEATURE_FLAG_ENVIRONMENT
+      }
+
+      return true
+    },
+    {
+      message:
+        'LAUNCHDARKLY_SDK_KEY is set, but FEATURE_FLAG_ENVIRONMENT is missing',
+      path: ['FEATURE_FLAG_ENVIRONMENT'],
+    }
+  )
 
 validateEnv(schema)

src/core/modules/feature-flags/context.ts

@@ -8,16 +8,20 @@ export type FeatureFlagContext = {
     slug?: string
     name?: string
   }
-  environment?: 'production' | 'preview' | 'development'
+  environment?: 'production' | 'staging'
 }
 
 export function getFeatureFlagEnvironment(): FeatureFlagContext['environment'] {
+  switch (process.env.FEATURE_FLAG_ENVIRONMENT) {
+    case 'production':
+    case 'staging':
+      return process.env.FEATURE_FLAG_ENVIRONMENT
+  }
+
   switch (process.env.VERCEL_ENV) {
     case 'production':
-    case 'preview':
-    case 'development':
-      return process.env.VERCEL_ENV
+      return 'production'
     default:
-      return 'development'
+      return 'staging'
   }
 }

src/core/modules/feature-flags/feature-flags.server.ts

@@ -12,11 +12,11 @@ import type {
   PayloadFeatureFlagDefinition,
 } from '@/core/modules/feature-flags/types'
 import { l, serializeErrorForLog } from '@/core/shared/clients/logger/logger'
-import {
-  type FeatureFlagProvider,
-  type FeatureFlagSnapshot,
-  postHogFeatureFlagProvider,
-} from './posthog-provider.server'
+import { launchDarklyOpenFeatureProvider } from './launchdarkly-openfeature-provider.server'
+import type {
+  FeatureFlagProvider,
+  FeatureFlagSnapshot,
+} from './provider.server'
 
 export type FeatureFlagService = {
   isEnabled(
@@ -89,12 +89,12 @@ function getEvaluatedValue(
 }
 
 export function createFeatureFlagService(
-  provider: FeatureFlagProvider = postHogFeatureFlagProvider
+  provider: FeatureFlagProvider = launchDarklyOpenFeatureProvider
 ): FeatureFlagService {
   return {
     async isEnabled(flagId, context) {
       const flag = FEATURE_FLAGS[flagId]
-      const snapshot = await provider.evaluate(context, [flag.key])
+      const snapshot = await provider.evaluate(context, [flag])
       const value = snapshot.getFlagValue(flag.key)
 
       if (typeof value === 'boolean') {
@@ -112,7 +112,7 @@ export function createFeatureFlagService(
       ][]
       const snapshot = await provider.evaluate(
         context,
-        flags.map(([, flag]) => flag.key)
+        flags.map(([, flag]) => flag)
       )
 
       return flags.map(([id, flag]) => ({