Feature flags (GrowthBook)

With --with feature-flags, nest-api evaluates GrowthBook flags on the server.

Variable	Value
GROWTHBOOK_API_HOST	https://cdn.growthbook.io (Cloud) or your GrowthBook’s API host
GROWTHBOOK_CLIENT_KEY	An SDK connection’s client key (sdk-…)

Both are required once the feature is on, and they ship empty.

Using it

Declare each flag in the AppFeatures interface in src/common/services/feature-flag.service.ts, so keys are type-checked and a renamed flag fails to compile instead of silently evaluating to its default.

@RequireFeature('new-checkout')
@Post('checkout')
checkout() { … }

@RequireFeature evaluates with the signed-in user’s id and role (or globally for anonymous requests) and answers 403 when the flag is off. In code, FeatureFlagService offers isOn, getValue and forUser(attributes).

Features load at startup (2-second timeout) and refresh every 60 seconds. If GrowthBook is unreachable, flags use their defaults and the API keeps running.