# Example Integration

**Scenario:** dApp requires:

* KYC ≤ 6 months old.
* Must match latest sanctions epoch.
* EU residents only.

```solidity
bytes32 constant POLICY_EU = keccak256("POOL.KYC2.EU");

bytes memory rule = abi.encode(
    POLICY_EU,
    userEASUID[msg.sender],
    bytes32(0),  // expected epoch root (latest)
    180 days     // max KYC age
);

(bool ok, uint32 reason) = policyEngine.isEligible(msg.sender, rule);
require(ok, _reason(reason));

```