feat: feature flags

packages/lib/constants/feature-flags.ts

@@ -0,0 +1,37 @@
+/**
+ * How frequent to poll for new feature flags in milliseconds.
+ */
+export const FEATURE_FLAG_POLL_INTERVAL = 30000;
+
+/**
+ * Feature flags that will be used when PostHog is disabled.
+ *
+ * Does not take any person or group properties into account.
+ */
+export const LOCAL_FEATURE_FLAGS: Record<string, boolean> = {
+  billing: process.env.NEXT_PUBLIC_FEATURE_BILLING_ENABLED === 'true',
+} as const;
+
+/**
+ * Extract the PostHog configuration from the environment.
+ */
+export function extractPostHogConfig(): { key: string; host: string } | null {
+  const postHogKey = process.env.NEXT_PUBLIC_POSTHOG_KEY;
+  const postHogHost = process.env.NEXT_PUBLIC_POSTHOG_HOST;
+
+  if (!postHogKey || !postHogHost) {
+    return null;
+  }
+
+  return {
+    key: postHogKey,
+    host: postHogHost,
+  };
+}
+
+/**
+ * Whether feature flags are enabled for the current instance.
+ */
+export function isFeatureFlagEnabled(): boolean {
+  return extractPostHogConfig() !== null;
+}