> ## Documentation Index
> Fetch the complete documentation index at: https://docs.base.org/llms.txt
> Use this file to discover all available pages before exploring further.

# IPolicyRegistry.updateBlocklist

> Adds or removes accounts from a BLOCKLIST policy in a single batch call.

## Signature

```solidity IPolicyRegistry.sol theme={null}
function updateBlocklist(uint64 policyId, bool blocked, address[] calldata accounts) external;
```

| Field               | Value                                    |
| ------------------- | ---------------------------------------- |
| Selector            | `0x5c4e51b8`                             |
| Canonical signature | `updateBlocklist(uint64,bool,address[])` |

## Description

Sets each address in `accounts` to the membership state `blocked` within the identified BLOCKLIST policy. A BLOCKLIST authorizes any account that is **not** in the set, so adding an account (`blocked = true`) causes `isAuthorized` to return `false` for that account, and removing it (`blocked = false`) restores authorization.

The change takes effect on the next `isAuthorized` query. Every token and composite policy that references `policyId` sees the updated result immediately, no second `updatePolicy` call is needed on any token.

Batches are capped by the registry, currently at 64 accounts. A larger batch reverts `BatchSizeTooLarge(maxBatchSize)`, which carries the limit.

Emits `BlocklistUpdated(policyId, updater, blocked, accounts)` on success.

## Parameters

| Name       | Type        | Description                                                                                                           |
| ---------- | ----------- | --------------------------------------------------------------------------------------------------------------------- |
| `policyId` | `uint64`    | The BLOCKLIST policy to update.                                                                                       |
| `blocked`  | `bool`      | Membership state to apply to every account in the batch. `true` adds accounts to the blocklist; `false` removes them. |
| `accounts` | `address[]` | Accounts to update. Capped at 64 per call.                                                                            |

## Reverts

| Error                             | Condition                                  |
| --------------------------------- | ------------------------------------------ |
| `Unauthorized()`                  | Caller is not the current policy admin.    |
| `PolicyNotFound()`                | `policyId` does not exist in the registry. |
| `IncompatiblePolicyType()`        | The policy is not a `BLOCKLIST`.           |
| `BatchSizeTooLarge(maxBatchSize)` | `accounts.length` exceeds 64.              |

## Access Control

Callable only by the current admin of `policyId`. Any other caller reverts `Unauthorized`.

## Example

```solidity Add accounts to a blocklist lines wrap expandable highlight={5,10} theme={null}
// Add two addresses to an existing BLOCKLIST policy.
address[] memory blocked = new address[](2);
blocked[0] = carol;
blocked[1] = dave;
IPolicyRegistry(registry).updateBlocklist(sanctionsId, true, blocked);

// Remove carol from the blocklist.
address[] memory unblocked = new address[](1);
unblocked[0] = carol;
IPolicyRegistry(registry).updateBlocklist(sanctionsId, false, unblocked);
```