Plan Limits & Entitlements

Feature gating with plan limits and Stripe Entitlements in Next.js Prisma

Gate features with numeric quotas (checkPlanLimit) or boolean flags (checkEntitlement). Define plan limits in your billing config and enforce them in code. Stripe Entitlements offer external feature gating managed through your Stripe dashboard.

This page is part of the Billing & Subscriptions documentation.

Two Approaches to Feature Gating

ApproachUse CaseSourceProvider Support
Plan LimitsNumeric quotas (seats, projects, storage)Billing configAll providers
Stripe EntitlementsBoolean feature flags (advanced-analytics, api-access)Stripe DashboardStripe only

When to use which:

  • Plan Limits: Countable resources that grow with usage (team members, API calls, storage)
  • Stripe Entitlements: Features that are either on or off (premium support, advanced analytics, white-labeling)

Plan Limits (Config-Based)

Plan limits are defined in your billing configuration and enforced by calling billing.checkPlanLimit() in your application code.

Defining Limits

Add limits to each plan in your billing config:

packages/billing/config/src/config.ts

import { BillingConfig } from '@kit/billing';
export const billingConfig: BillingConfig = {
  // Default limits for users without a subscription (free tier)
  defaultLimits: {
    projects: 1,
    aiTokens: 10_000,
  },
  products: [
    {
      id: 'starter',
      name: 'Starter',
      description: 'Perfect for individuals',
      currency: 'USD',
      features: ['Up to 3 team members', 'Core features'],
      plans: [
        {
          name: 'starter-monthly',
          planId: process.env.NEXT_PUBLIC_STRIPE_STARTER_MONTHLY_PLAN_ID!,
          displayName: 'Starter Monthly',
          interval: 'month',
          cost: 9.99,
          limits: {
            seats: 3,
            projects: 10,
            aiTokens: 50_000,
          },
        },
      ],
    },
    {
      id: 'pro',
      name: 'Pro',
      description: 'Best for growing teams',
      currency: 'USD',
      features: ['Up to 10 team members', 'Priority support'],
      plans: [
        {
          name: 'pro-monthly',
          planId: process.env.NEXT_PUBLIC_STRIPE_PRO_MONTHLY_PLAN_ID!,
          displayName: 'Pro Monthly',
          interval: 'month',
          cost: 29.99,
          limits: {
            seats: 10,
            projects: 100,
            aiTokens: 500_000,
          },
        },
      ],
    },
    {
      id: 'enterprise',
      name: 'Enterprise',
      description: 'For large organizations',
      currency: 'USD',
      features: ['Unlimited team members', 'Dedicated support'],
      plans: [
        {
          name: 'enterprise-monthly',
          planId: process.env.NEXT_PUBLIC_STRIPE_ENTERPRISE_MONTHLY_PLAN_ID!,
          displayName: 'Enterprise Monthly',
          interval: 'month',
          cost: 99.99,
          limits: {
            seats: null,      // null = unlimited
            projects: null,
            aiTokens: null,
          },
        },
      ],
    },
  ],
};

Default Limits (Free Tier)

The defaultLimits config applies when a user has no active subscription:

export const billingConfig: BillingConfig = {
  defaultLimits: {
    projects: 1,        // Free users can create 1 project
    aiTokens: 10_000,   // Free users get 10K tokens/month
    seats: 1,           // Free users can have 1 team member
  },
  products: [/* ... */],
};

Checking Limits with checkPlanLimit()

Use billing.checkPlanLimit() to validate before allowing an action:

packages/billing/ui/src/services/example.service.ts

import { auth } from '@kit/better-auth';
import { getBilling } from '@kit/billing-api';
export async function checkProjectLimit(organizationId: string) {
  const billing = await getBilling(auth);
  // Get current project count from your database
  const currentProjectCount = await getProjectCount(organizationId);
  // Check if limit allows creating another project
  const { allowed, limit, remaining, hasSubscription } =
    await billing.checkPlanLimit({
      referenceId: organizationId,
      limitKey: 'projects',
      currentUsage: currentProjectCount,
    });
  if (!allowed) {
    throw new Error(
      `Project limit reached (${limit}). Upgrade your plan to create more projects.`
    );
  }
  return { allowed, remaining };
}

Return Type

checkPlanLimit() returns a CheckPlanLimitResult object:

interface CheckPlanLimitResult {
  /** Whether the action is allowed based on the limit */
  allowed: boolean;
  /** The limit value (null = unlimited) */
  limit: number | null;
  /** Current usage count (passed in) */
  current: number;
  /** Remaining capacity (null = unlimited) */
  remaining: number | null;
  /** Whether the referenceId has an active subscription */
  hasSubscription: boolean;
}

Important: allowed is true when currentUsage < limit (not <=), allowing the user to add one more item up to the limit.

Getting All Limits

To display limits in the UI or check multiple limits at once:

import { auth } from '@kit/better-auth';
import { getBilling } from '@kit/billing-api';
const billing = await getBilling(auth);
const { limits, hasSubscription } = await billing.getPlanLimits(organizationId);
// limits is Record<string, number | null>
console.log(limits);
// { seats: 10, projects: 100, aiTokens: 500_000 }

Stripe Entitlements (Boolean Feature Flags)

Stripe Entitlements provide external feature gating managed entirely in your Stripe dashboard. Use them for features that are on/off rather than countable.

Setting Up Entitlements in Stripe

  1. Go to Stripe Dashboard → Product catalog → Entitlements
  2. Create features with lookup keys (e.g., advanced-analytics, api-access, white-label)
  3. Attach features to your products
  4. When customers subscribe, they automatically get the entitlements

Checking Entitlements

packages/billing/ui/src/services/entitlements.service.ts

import { auth } from '@kit/better-auth';
import { getBilling } from '@kit/billing-api';
export async function checkFeatureAccess(customerId: string) {
  const billing = await getBilling(auth);
  const { entitled, source } = await billing.checkEntitlement(
    customerId,
    'advanced-analytics'
  );
  if (!entitled) {
    throw new Error('Advanced analytics requires a Pro plan or higher.');
  }
  // Feature is available
  return { entitled };
}

Return Type

checkEntitlement() returns a CheckEntitlementResult object:

interface CheckEntitlementResult {
  /** Whether the customer has the entitlement */
  entitled: boolean;
  /** Source of the check: 'provider' or 'unsupported' */
  source: 'provider' | 'unsupported';
}

When source is 'unsupported', the provider doesn't support entitlements (e.g., Polar) and entitled defaults to false.

Listing All Entitlements

import { auth } from '@kit/better-auth';
import { getBilling } from '@kit/billing-api';
const billing = await getBilling(auth);
const entitlements = await billing.listEntitlements(customerId);
// entitlements is Entitlement[]
// [{ id: 'ent_xxx', featureId: 'feat_xxx', lookupKey: 'advanced-analytics' }]
const hasApiAccess = entitlements.some(e => e.lookupKey === 'api-access');

Getting the Customer ID

Entitlement methods require the provider's customer ID (e.g., cus_xxx for Stripe):

import { auth } from '@kit/better-auth';
import { getBilling } from '@kit/billing-api';
const billing = await getBilling(auth);
// For personal billing (user object from session)
const customerId = billing.getCustomerId(user);
// For organization billing (user and organization from session/context)
const customerId = billing.getCustomerId(user, organization, 'organization');

Implementation Patterns

Server Action with Plan Limits

apps/web/app/[locale]/(internal)/projects/_lib/projects-server-actions.ts

'use server';
import { revalidatePath } from 'next/cache';
import { z } from 'zod';
import { authenticatedActionClient } from '@kit/action-middleware';
import { auth } from '@kit/better-auth';
import { requireActiveOrganizationId } from '@kit/better-auth/context';
import { getBilling } from '@kit/billing-api';
const createProjectSchema = z.object({
  name: z.string().min(1).max(100),
});
export const createProjectAction = authenticatedActionClient
  .inputSchema(createProjectSchema)
  .action(async ({ parsedInput }) => {
    const organizationId = await requireActiveOrganizationId();
    const billing = await getBilling(auth);
    // Get current count from your database
    const currentCount = await getProjectCount(organizationId);
    // Check limit
    const { allowed } = await billing.checkPlanLimit({
      referenceId: organizationId,
      limitKey: 'projects',
      currentUsage: currentCount,
    });
    if (!allowed) {
      throw new Error('Project limit reached. Please upgrade your plan.');
    }
    // Create the project
    const project = await createProject({
      organizationId,
      name: parsedInput.name,
    });
    revalidatePath('/projects');
    return { success: true, data: project };
  });

Lifecycle Hook Integration

Combine entitlements with lifecycle hooks for provisioning:

packages/billing/stripe/src/hooks/on-subscription-created.ts

import billingConfig from '@kit/web-billing-config';
import { getLogger } from '@kit/shared/logger';
/**
 * Hook called when a new subscription is created.
 * Extend this to provision resources, send emails, etc.
 */
export async function onSubscriptionCreated(subscription: {
  id: string;
  plan: string;
  referenceId: string;
  status: string | null;
  providerCustomerId?: string | null;
  providerSubscriptionId?: string | null;
}): Promise<void> {
  const logger = await getLogger();
  logger.info(
    {
      subscriptionId: subscription.id,
      plan: subscription.plan,
      referenceId: subscription.referenceId,
      status: subscription.status,
    },
    'Subscription created successfully'
  );
  // Entitlements are automatically granted by Stripe
  // based on the product's attached features.
  //
  // Use this hook to provision resources based on plan limits:
  const planConfig = billingConfig.products
    .flatMap(p => p.plans)
    .find(p => p.name === subscription.plan);
  if (planConfig?.limits) {
    // Example: provision resources for the new subscription
    await provisionResources({
      referenceId: subscription.referenceId,
      limits: planConfig.limits,
    });
  }
}

UI Component for Limit Display

apps/web/app/[locale]/(internal)/settings/billing/_components/usage-card.tsx

'use client';
interface UsageCardProps {
  label: string;
  current: number;
  limit: number | null;
}
export function UsageCard({ label, current, limit }: UsageCardProps) {
  const isUnlimited = limit === null;
  const percentage = isUnlimited ? 0 : (current / limit) * 100;
  const isNearLimit = !isUnlimited && percentage >= 80;
  return (
    <div className="rounded-lg border p-4">
      <div className="flex justify-between">
        <span className="text-sm text-muted-foreground">{label}</span>
        <span className={isNearLimit ? 'text-destructive' : ''}>
          {current} / {isUnlimited ? 'Unlimited' : limit}
        </span>
      </div>
      {!isUnlimited && (
        <div className="mt-2 h-2 rounded-full bg-muted">
          <div
            className={`h-full rounded-full ${
              isNearLimit ? 'bg-destructive' : 'bg-primary'
            }`}
            style={{ width: `${Math.min(percentage, 100)}%` }}
          />
        </div>
      )}
    </div>
  );
}

Provider Support Matrix

FeatureStripePolar
Plan Limits (checkPlanLimit)SupportedSupported
Default Limits (free tier)SupportedSupported
Entitlements (checkEntitlement)SupportedNot supported
List EntitlementsSupportedReturns empty array

When using Polar, checkEntitlement() returns { entitled: false, source: 'unsupported' }. Use plan limits or custom logic instead.

Limits vs Entitlements Decision Guide

Use Plan Limits when:

  • The feature is countable (seats, projects, storage, API calls)
  • You need to track current usage
  • The limit varies by plan tier
  • You want free tier limits

Use Stripe Entitlements when:

  • The feature is boolean (on/off)
  • You want Stripe to manage feature access
  • You need real-time entitlement updates
  • You're building complex product bundles in Stripe

Common Pitfalls

  • Forgetting to check limits in code: Limits are declarative only. If you don't call checkPlanLimit(), nothing is enforced.
  • Using <= instead of < comparison: The allowed check uses currentUsage < limit so users can add up to (not including) the limit. One more item is allowed when at limit - 1.
  • Not handling the hasSubscription field: When hasSubscription is false, default limits apply. You may want different UX for free users vs subscribers.
  • Expecting entitlements on Polar: Polar doesn't support entitlements. Use plan limits or custom feature flags instead.
  • Caching stale limits: Plan limits can change when users upgrade. Always check at action time, not page load.
  • Missing defaultLimits config: Without defaultLimits, users without subscriptions get no limits (everything undefined = unlimited by default).

Frequently Asked Questions

How do I show remaining usage in the UI?
Call getPlanLimits() to get all limits, then calculate remaining = limit - currentUsage for each. Display in a usage card component.
Can I combine limits and entitlements?
Yes. Use limits for quotas (max projects) and entitlements for feature flags (has advanced analytics). They serve different purposes.
What happens if a user downgrades?
Existing resources remain but new ones are blocked. You may want a lifecycle hook to handle over-limit situations gracefully.
How do I test entitlements locally?
Create test products in Stripe test mode with entitlements attached. Subscribe via test checkout and verify with checkEntitlement().
Can I have different limits for monthly vs yearly plans?
Yes. Each plan object has its own limits property. Set different values per interval if needed.
How do I handle the null (unlimited) case in UI?
Check for null explicitly: limit === null means unlimited. Display 'Unlimited' or hide the progress bar.

Next: Metered Usage →