# CCIP v1.5.1 Events API Reference
Source: https://docs.chain.link/ccip/v1/evm/api-reference/v1.5.1/events

> For the complete documentation index, see [llms.txt](/llms.txt).

> **NOTE: Integrate Chainlink CCIP v1.5.1 into your project**
>
> ### npm
>
> If you use [NPM](https://www.npmjs.com/), install the [@chainlink/contracts-ccip NPM package](https://www.npmjs.com/package/@chainlink/contracts-ccip):
>
> ```shell
> npm install @chainlink/contracts-ccip@1.5.1-beta.0
> ```
>
> ### yarn
>
> If you use [Yarn](https://yarnpkg.com/), install the [@chainlink/contracts-ccip NPM package](https://www.npmjs.com/package/@chainlink/contracts-ccip):
>
> ```shell
> yarn add @chainlink/contracts-ccip@1.5.1-beta.0
> ```
>
> ### foundry
>
> If you use [Foundry](https://book.getfoundry.sh/), install the package:
>
> ```shell
> forge install smartcontractkit/ccip@5e7b2096586bc32c6e975fc13f4c411eb687f833
> ```

When invoking the `ccipSend` [function](/ccip/v1/evm/api-reference/v1.5.1/i-router-client#ccipsend) or when a message is executed via `ccipReceive`, various events are emitted by CCIP contracts. Below is a compiled list of events you can expect during CCIP operations.

## `ccipSend`

These events are emitted when sending a cross-chain message using the `ccipSend` [function](/ccip/v1/evm/api-reference/v1.5.1/i-router-client#ccipsend).

### OnRamp

| Event               | Parameters                                                                                       | Description                                       |
| ------------------- | ------------------------------------------------------------------------------------------------ | ------------------------------------------------- |
| `CCIPSendRequested` | [`Internal.EVM2EVMMessage`](/ccip/v1/evm/api-reference/v1.5.1/internal#evm2evmmessage) `message` | Emitted when a CCIP message is successfully sent. |

### Token Pool (Send)

| Event    | Parameters                                 | Description                                                   |
| -------- | ------------------------------------------ | ------------------------------------------------------------- |
| `Locked` | `address indexed sender`, `uint256 amount` | Emitted when tokens are locked during a cross-chain transfer. |
| `Burned` | `address indexed sender`, `uint256 amount` | Emitted when tokens are burned during a cross-chain transfer. |

## `ccipReceive`

These events are emitted when a cross-chain message is executed on the destination chain.

### OffRamp

| Event                   | Parameters                                                                                                                                                                                     | Description                                                           |
| ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------- |
| `ExecutionStateChanged` | `uint64 indexed sequenceNumber`, `bytes32 indexed messageId`, [`Internal.MessageExecutionState`](/ccip/v1/evm/api-reference/v1.5.1/internal#messageexecutionstate) `state`, `bytes returnData` | Emitted when a message execution state changes to SUCCESS or FAILURE. |

### Router

| Event             | Parameters                                                                                   | Description                                                            |
| ----------------- | -------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------- |
| `MessageExecuted` | `bytes32 messageId`, `uint64 sourceChainSelector`, `address offRamp`, `bytes32 calldataHash` | Emitted when the Router successfully routes a message to the receiver. |

### Token Pool (Receive)

| Event      | Parameters                                                              | Description                                                                |
| ---------- | ----------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| `Released` | `address indexed sender`, `address indexed recipient`, `uint256 amount` | Emitted when tokens are released to the receiver on the destination chain. |
| `Minted`   | `address indexed sender`, `address indexed recipient`, `uint256 amount` | Emitted when tokens are minted to the receiver on the destination chain.   |