> ## 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.

# IB20Asset.announce

> Wraps one or more asset calls in a disclosed announcement bracket, emitting Announcement and EndAnnouncement with the same id.

## Signature

```solidity IB20Asset.sol theme={null}
function announce(
    bytes[] calldata internalCalls,
    string calldata id,
    string calldata description,
    string calldata uri
) external;
```

| Field               | Value                                    |
| ------------------- | ---------------------------------------- |
| Selector            | `0x595135dd`                             |
| Canonical signature | `announce(bytes[],string,string,string)` |

## Description

Emits `Announcement(caller, id, description, uri)`, executes every entry in `internalCalls` atomically via self-`delegatecall` (preserving `msg.sender`), then emits `EndAnnouncement(id)`. Pass an empty `internalCalls` array for a notice with no on-chain effect; both events still fire and `id` is consumed.

Indexers pair open and close brackets by `id`. Every event emitted between the two logs belongs to the announced action. A state-changing call that appears outside this bracket was invoked directly, not through `announce`.

* Execution order: emit `Announcement` → run inner calls → emit `EndAnnouncement`. If any inner call fails, the whole transaction reverts and `id` is not consumed.
* After a successful call, `isAnnouncementIdUsed(id)` returns `true`.
* `announce` is defined on **B20 Asset** only. Stablecoin has no announcements.
* Typical inner calls: `updateUIMultiplier`, `cancelUIMultiplierUpdate`, `batchMint`, `mintWithMemo`, `burnWithMemo`.

## Parameters

| Name            | Type      | Description                                                                                                                        |
| --------------- | --------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| `internalCalls` | `bytes[]` | ABI-encoded calldata blobs executed in order via self-`delegatecall`. Each entry must be at least 4 bytes. May be empty.           |
| `id`            | `string`  | Caller-chosen announcement identifier. Single-use over the token's lifetime. A successful `announce` consumes `id`; reuse reverts. |
| `description`   | `string`  | Human-readable summary shown to holders. The asset does not verify this string.                                                    |
| `uri`           | `string`  | Off-chain URI for the full announcement record. The asset does not verify this string.                                             |

## Reverts

| Error                                                     | Condition                                                                                                                   |
| --------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------- |
| `AccessControlUnauthorizedAccount(caller, OPERATOR_ROLE)` | Caller does not hold `OPERATOR_ROLE`.                                                                                       |
| `AnnouncementIdAlreadyUsed(id)`                           | A prior successful `announce` already consumed `id`.                                                                        |
| `InternalCallMalformed(call)`                             | An entry in `internalCalls` is shorter than 4 bytes.                                                                        |
| `AnnouncementInProgress()`                                | An inner call targets `announce` itself.                                                                                    |
| `InternalCallFailed(call)`                                | An inner call reverted with an ordinary revert. The underlying reason is not bubbled; replay the call directly to diagnose. |

A Solidity `Panic` inside an inner call (for example arithmetic overflow) propagates raw and is not wrapped as `InternalCallFailed`.

## Access Control

`OPERATOR_ROLE` gates this call. Any other caller reverts `AccessControlUnauthorizedAccount`. Inner calls keep their own role gates; the operator must hold every role the inner calls require (for example `MINT_ROLE` for `batchMint`, `BURN_ROLE` for `burnWithMemo`).

## Example

```solidity Scheduled split wrapped in an announcement theme={null}
bytes[] memory calls = new bytes[](1);
calls[0] = abi.encodeCall(IB20Asset.updateUIMultiplier, (2e18, effectiveAt));

asset.announce(calls, id, description, uri);
// Emits: Announcement → UIMultiplierUpdated → EndAnnouncement
```

```solidity Notice with no inner calls theme={null}
asset.announce(new bytes[](0), id, description, uri);
// Emits: Announcement → EndAnnouncement
```