> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nozle.dev/llms.txt
> Use this file to discover all available pages before exploring further.
# Entitlements Overview
> Enforce feature access and usage limits from a trusted backend
Entitlements control what a customer can do based on subscription and usage state.
## Two decision types
1. **Feature gates** — boolean access, such as analytics or SSO.
2. **Usage limits** — numeric caps, such as monthly requests or generated reports.
## Server-side enforcement
```ts theme={null}
const check = await nozle.can('customer_123', 'api_calls')
if (!check.allowed) {
return Response.json(
{ error: check.reason ?? 'not_allowed', remaining: check.remaining },
{ status: check.overage ? 429 : 403 },
)
}
return performProtectedWork()
```
Call `can()` immediately before protected work. The response can include usage and margin context in addition to the allow/deny decision.
## React presentation
Fetch entitlement state through your authenticated backend and pass it into presentational gates:
```tsx theme={null}
}
>
```
The React component improves the interface; your backend check remains the authorization boundary.
## Updates
Refresh entitlement state after checkout, subscription, or usage changes. For push-based updates, issue a separate server-authorized realtime token or publish through your own authenticated channel. Never send `pk_` or `sk_` credentials to a browser WebSocket connection.
## Margin-aware decisions
`can()` can return unit cost, revenue, margin, thresholds, and warnings. Use those fields for observability or merchant-defined policy without exposing them to customers unless required.