# Event Bot Monitoring

### What is Event Bot Monitoring?

> An event refers to an event in a smart contract, triggered when a certain transaction occurs. Users can track these events to trace transactions.

Event Monitoring listens for specific behaviors on-chain by monitoring events emitted by smart contracts.

### Typical Scenarios for Event Bot Monitoring

1. Defi Liquidity Event Monitoring
   1. Defi liquidity exceeds a set threshold.
   2. Defi liquidity falls below a set threshold.
2. NFT Mint Event Monitoring
   1. A specific NFT starts minting.
3. Token Mint Event Monitoring
   1. Large token unlock monitoring.
4. Others, etc.

#### Supported Data Sources

| Data Source   | Type     | Stability |
| ------------- | -------- | --------- |
| Ethereum      | on chain | Very High |
| BSC           | on chain | High      |
| Avalanche     | on chain | High      |
| Polygon Pos   | on chain | High      |
| Arbitrum      | on chain | High      |
| Optimism      | on chain | High      |
| Polygon zkEVM | on chain | High      |
| ZkSync Era    | on chain | High      |
| Base          | on chain | High      |
| Scroll        | on chain | High      |
| Manta         | on chain | High      |
| ZKFair        | on chain | High      |
| Blast         | on chain | High      |
| Linea         | on chain | High      |
| B2            | on chain | High      |
| Merlin        | on chain | High      |

### How to Configure Event Bot Monitoring?

After logging in to the ChainBot platform, select "Create Bot" in the upper right corner -> "Event Monitor".

<figure><img src="https://3957434529-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fytm2ftx9VGhS1jFp37FQ%2Fuploads%2Fgit-blob-a17053ad22c496ad7f127f1edae7fe4d112c60ee%2FWeChat68e235d340c98acdf8e5d9bdcdecf61c.png?alt=media" alt=""><figcaption><p>Chosen Event Monitor</p></figcaption></figure>

⚠️ Note

When a specific Event is selected, Conditions will automatically parse the fields contained in that Event, limited to the Event's fields. Therefore, Event and Conditions have a corresponding relationship.

#### Info Description

| Field Name | Description                                | Required |
| ---------- | ------------------------------------------ | -------- |
| Name       | Monitoring Bot Name                        | Yes      |
| Chain      | Selected Chain                             | Yes      |
| Contract   | Selected Contract                          | Yes      |
| Event      | Selected Event                             | Yes      |
| Tags       | Bot monitoring tags, beneficial for search | Yes      |

#### Conditions Description

Conditions in Event Monitoring dynamically change based on the selected Event.

For example, when monitoring the Approval event in the USDT contract, as the parameters of Event Approval(owner: address, spender: address, value: uint256) are three, the available fields in conditions are also three, namely owner, spender, value. Configure your parameters based on your conditions to achieve your purpose.

#### Template Variables Description

| Variable            | Description                               | Example                 |
| ------------------- | ----------------------------------------- | ----------------------- |
| $alert.time         | Block in which the event occurred         | 16073651                |
| $tx.hash            | Transaction hash generating the event     | transaction hash        |
| $event.contract     | Contract address where the event occurred | 16073651                |
| $event.params.{abc} | Key fields parsed from the event          | $event.params.tokens    |
| $chain.explore      | Current chain explorer prefix             | <https://etherscan.io/> |

#### Default Notification Template

```
[ {$bot.name} ]
Contract: {$event.contract}
Time: {$alert.time}
Explore: {$chain.explore}/tx/{$tx.hash}
```

[Learn about alarm notification templates?](https://github.com/ChainbotAI/doc-en/blob/master/advanced-features/alarm-notification-template/README.md)

#### Notification Message Example

> \[ CRV Liquidation Call Monitor ]\
> Contract: 0x7d2768dE32b0b80b7a3454c06BdAc94A69DDc7A9\
> Amount: 187743.2161384799 CRV\
> Time: 2022-11-23T02:09:23+08:00\
> Explore: <https://etherscan.io/tx/0x47ffc7939cf8deed6a28357934f98402892b370ac2d3be0c6576f733f6d97b1e>\
> Created By [ChainBot.io](http://chainbot.io/)

#### Event Bot Monitoring Case Study

[event-bot-demo](https://docs.chainbot.io/bot-case/event-bot-demo "mention")