Feature Flags

Shipkit detects which features are available at build time by checking environment variables. No manual flag configuration needed — set the env vars for a feature and it turns on.

How It Works

src/config/features-config.ts runs during build. It:

1. Checks which env vars are present
2. Sets buildTimeFeatures.FEATURE_NAME = true/false
3. Generates NEXT_PUBLIC_FEATURE_* flags for client-side checks
4. Only enabled flags are injected (disabled = undefined, not false)

Usage

Client-side

import { env } from "@/env";

if (env.NEXT_PUBLIC_FEATURE_STRIPE_ENABLED) {
  // only runs when Stripe env vars are set
}

Build-time (Next.js config, plugins)

import { buildTimeFeatures } from "@/config/features-config";

if (buildTimeFeatures.PAYLOAD_ENABLED) {
  // configure Payload plugin
}

Env Var Mirroring

Shipkit auto-mirrors server-side public keys to NEXT_PUBLIC_ variants at build time. You can set:

STRIPE_PUBLISHABLE_KEY=pk_test_...

And NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY will be generated automatically. Only whitelisted keys are mirrored (see PUBLIC_ENV_BASE_KEYS in features-config.ts).

Mirrored keys: BUILDER_API_KEY, CLERK_PUBLISHABLE_KEY, SUPABASE_URL, SUPABASE_ANON_KEY, STRIPE_PUBLISHABLE_KEY, POSTHOG_KEY, UMAMI_WEBSITE_ID, DATAFAST_WEBSITE_ID, DATAFAST_DOMAIN, STATSIG_CLIENT_KEY, GOOGLE_ANALYTICS_ID, GOOGLE_GTM_ID, C15T_URL, VERCEL_INTEGRATION_SLUG.

APP_SECRET Derivation

If APP_SECRET is set, secrets like PAYLOAD_SECRET and BETTER_AUTH_SECRET are treated as satisfied — they derive from the master secret. One env var, multiple features.

Complete Flag Reference

Core

Flag	Enabled when	Disable with
DATABASE_ENABLED	DATABASE_URL set	—
PAYLOAD_ENABLED	Database + PAYLOAD_SECRET (or APP_SECRET)	DISABLE_PAYLOAD=true
BUILDER_ENABLED	NEXT_PUBLIC_BUILDER_API_KEY set	DISABLE_BUILDER=true
MDX_ENABLED	Always (default on)	DISABLE_MDX=true
PWA_ENABLED	Always (default on)	DISABLE_PWA=true
DEVTOOLS_ENABLED	ENABLE_DEVTOOLS=true	—

Authentication

Flag	Enabled when	Disable with
AUTH_JS_ENABLED	Any Auth.js provider enabled	—
BETTER_AUTH_ENABLED	BETTER_AUTH_SECRET (or APP_SECRET)	DISABLE_BETTER_AUTH=true
AUTH_CLERK_ENABLED	CLERK_PUBLISHABLE_KEY + CLERK_SECRET_KEY	DISABLE_AUTH_CLERK=true
AUTH_STACK_ENABLED	STACK_PROJECT_ID + STACK_PUBLISHABLE_CLIENT_KEY + STACK_SECRET_SERVER_KEY	DISABLE_AUTH_STACK=true
SUPABASE_AUTH_ENABLED	SUPABASE_URL + SUPABASE_ANON_KEY	DISABLE_SUPABASE_AUTH=true
AUTH_GUEST_ENABLED	ENABLE_AUTH_GUEST=true	—
AUTH_CREDENTIALS_ENABLED	Payload enabled	DISABLE_AUTH_CREDENTIALS=true
AUTH_RESEND_ENABLED	RESEND_API_KEY (dev only)	DISABLE_AUTH_RESEND=true
AUTH_GITHUB_ENABLED	AUTH_GITHUB_ID + AUTH_GITHUB_SECRET	DISABLE_AUTH_GITHUB=true
AUTH_GOOGLE_ENABLED	AUTH_GOOGLE_ID + AUTH_GOOGLE_SECRET	DISABLE_AUTH_GOOGLE=true
AUTH_DISCORD_ENABLED	AUTH_DISCORD_ID + AUTH_DISCORD_SECRET	DISABLE_AUTH_DISCORD=true
AUTH_TWITTER_ENABLED	AUTH_TWITTER_ID + AUTH_TWITTER_SECRET	DISABLE_AUTH_TWITTER=true
AUTH_GITLAB_ENABLED	AUTH_GITLAB_ID + AUTH_GITLAB_SECRET	DISABLE_AUTH_GITLAB=true
AUTH_BITBUCKET_ENABLED	AUTH_BITBUCKET_ID + AUTH_BITBUCKET_SECRET	DISABLE_AUTH_BITBUCKET=true
AUTH_VERCEL_ENABLED	VERCEL_CLIENT_ID + VERCEL_CLIENT_SECRET	DISABLE_AUTH_VERCEL=true
AUTH_ENABLED	Any auth provider enabled	—

Payments

Flag	Enabled when	Disable with
LEMONSQUEEZY_ENABLED	LEMONSQUEEZY_API_KEY + LEMONSQUEEZY_STORE_ID	DISABLE_LEMONSQUEEZY=true
STRIPE_ENABLED	STRIPE_SECRET_KEY + STRIPE_PUBLISHABLE_KEY	DISABLE_STRIPE=true
POLAR_ENABLED	POLAR_ACCESS_TOKEN	DISABLE_POLAR=true

Storage

Flag	Enabled when	Disable with
S3_ENABLED	AWS_REGION + AWS_ACCESS_KEY_ID + AWS_SECRET_ACCESS_KEY + AWS_BUCKET_NAME	DISABLE_S3=true
VERCEL_BLOB_ENABLED	VERCEL_BLOB_READ_WRITE_TOKEN	DISABLE_VERCEL_BLOB=true
FILE_UPLOAD_ENABLED	S3 or Vercel Blob enabled	—

Analytics

Flag	Enabled when	Disable with
POSTHOG_ENABLED	POSTHOG_KEY	DISABLE_POSTHOG=true
UMAMI_ENABLED	UMAMI_WEBSITE_ID	DISABLE_UMAMI=true
DATAFAST_ENABLED	DATAFAST_WEBSITE_ID	DISABLE_DATAFAST=true
STATSIG_ENABLED	STATSIG_CLIENT_KEY	DISABLE_STATSIG=true
GOOGLE_ANALYTICS_ENABLED	GOOGLE_ANALYTICS_ID	DISABLE_GOOGLE_ANALYTICS=true
GOOGLE_TAG_MANAGER_ENABLED	GOOGLE_GTM_ID	DISABLE_GOOGLE_TAG_MANAGER=true

Infrastructure

Flag	Enabled when	Disable with
REDIS_ENABLED	UPSTASH_REDIS_REST_URL + UPSTASH_REDIS_REST_TOKEN	DISABLE_REDIS=true
VERCEL_INTEGRATION_ENABLED	VERCEL_INTEGRATION_SLUG + VERCEL_CLIENT_ID + VERCEL_CLIENT_SECRET	DISABLE_VERCEL_INTEGRATION=true

AI / External Services

Flag	Enabled when	Disable with
OPENAI_ENABLED	OPENAI_API_KEY	DISABLE_OPENAI=true
ANTHROPIC_ENABLED	ANTHROPIC_API_KEY	DISABLE_ANTHROPIC=true
GITHUB_API_ENABLED	GITHUB_ACCESS_TOKEN	DISABLE_GITHUB_API=true

Other

Flag	Enabled when	Disable with
LIGHT_MODE_ENABLED	Always (default on)	DISABLE_LIGHT_MODE=true
DARK_MODE_ENABLED	Always (default on)	DISABLE_DARK_MODE=true
C15T_ENABLED	C15T_URL	DISABLE_C15T=true
CONSENT_MANAGER_ENABLED	C15T or ENABLE_CONSENT_MANAGER=true	DISABLE_CONSENT_MANAGER=true
TURNSTILE_ENABLED	TURNSTILE_SITE_KEY + TURNSTILE_SECRET_KEY	—

Adding a New Feature Flag

1. Add detection in src/config/features-config.ts:

buildTimeFeatures.MY_FEATURE_ENABLED =
  hasEnv("MY_API_KEY") && !envIsTrue("DISABLE_MY_FEATURE");

2. Add the env var to src/env.ts for type safety.
3. Use env.NEXT_PUBLIC_FEATURE_MY_FEATURE_ENABLED client-side or buildTimeFeatures.MY_FEATURE_ENABLED at build time.

Key Files

File	Purpose
src/config/features-config.ts	Feature detection + flag generation
src/env.ts	T3 Env schema (runtime validation)