> ## Documentation Index
> Fetch the complete documentation index at: https://base-a060aa97-docs-sync-code-change-91427ab.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# IPolicyRegistry.isAuthorized

> Returns whether an account is authorized under a policy ID, including inverted (NOT) policy semantics.

## Signature

```solidity IPolicyRegistry.sol theme={null}
function isAuthorized(uint64 policyId, address account) external view returns (bool);
```

| Field               | Value                          |
| ------------------- | ------------------------------ |
| Selector            | `0x55a1179e`                   |
| Canonical signature | `isAuthorized(uint64,address)` |

## Description

Returns whether `account` is authorized under `policyId`. Never reverts.

Unknown or malformed IDs collapse to empty-member-set semantics (`ALLOWLIST` → `false`, `BLOCKLIST` → `true`).

Callers that store policy IDs MUST validate `policyExists(policyId)` at write time.

### Invert (NOT) semantics

When bit 63 of `policyId` is set (the invert flag), `isAuthorized` resolves the base policy (`policyId & ~INVERT_BIT`) and returns the **opposite** of its result:

* If the base policy does not exist, returns `false` (fail-closed). A missing or malformed base is never treated as allow-everyone.
* If the base policy exists, returns `!isAuthorized(base, account)`.

This applies to every policy type: `ALLOWLIST`, `BLOCKLIST`, `UNION`, and `INTERSECT`.

Use `invertedPolicyId(policyId)` to set or clear bit 63. The inverted ID has no record of its own; members live on the base.

```mermaid theme={null}
flowchart TD
    Q["isAuthorized(policyId, account)"] --> Inv{"bit 63 set?"}
    Inv -->|no| T[Dispatch on policy type]
    Inv -->|yes| E{"policyExists(base)?"}
    E -->|no| F[false]
    E -->|yes| N["not isAuthorized(base, account)"]
```

## Parameters

| Name       | Type      | Description                                              |
| ---------- | --------- | -------------------------------------------------------- |
| `policyId` | `uint64`  | Policy to query. Bit 63 may be set to invert the result. |
| `account`  | `address` | Account to check.                                        |

## Returns

`bool` — `true` if `account` is authorized under `policyId`, `false` otherwise.

## Access Control

View function. No role or admin restriction.

## Policy Interaction

This is part of the singleton PolicyRegistry surface used by B20 policy scopes.

## Example

```solidity Usage Example theme={null}
// Plain policy
bool ok = StdPrecompiles.POLICY_REGISTRY.isAuthorized(policyId, account);

// Inverted policy: authorized if account is NOT in the base policy's member set
uint64 notExcluded = StdPrecompiles.POLICY_REGISTRY.invertedPolicyId(exclusionId);
bool notOnExclusionList = StdPrecompiles.POLICY_REGISTRY.isAuthorized(notExcluded, account);
```