---
title: TCP event handler
description: The “tcp” event handler allows you to send Kapacitor alert data to a TCP endpoint. This page includes options and usage examples.
url: https://docs.influxdata.com/kapacitor/v1/reference/event_handlers/tcp/
estimated_tokens: 1945
product: Kapacitor
version: v1
---

# TCP event handler

The TCP event handler sends JSON encoded alert data to a TCP endpoint.

## Options

The following TCP event handler options can be set in a [handler file](/kapacitor/v1/reference/event_handlers/#create-a-topic-handler-with-a-handler-file) or when using `.tcp()` in a TICKscript.

| Name | Type | Description |
| --- | --- | --- |
| address | string | Address of TCP endpoint. |

### Example: handler file

```yaml
id: handler-id
topic: topic-name
kind: tcp
options:
  address: 127.0.0.1:7777
```

### Example: TICKscript

```js
|alert()
  // ...
  .tcp('127.0.0.1:7777')
```

## Using the TCP event handler

The TCP event handler can be used in both TICKscripts and handler files to send alert data to TCP endpoint.

### Send alert data to a TCP endpoint from a TICKscript

The following TICKscript uses the `.tcp()` event handler to send alert data whenever idle CPU usage drops below 10%.

***tcp-cpu-alert.tick***

```js
stream
  |from()
    .measurement('cpu')
  |alert()
    .crit(lambda: "usage_idle" < 10)
    .message('Hey, check your CPU')
    .tcp('127.0.0.1:7777')
```

### Send alert data to a TCP endpoint from a defined handler

The following setup sends an alert to the `cpu` topic with the message, “Hey, check your CPU”. A TCP handler is added that subscribes to the `cpu` topic and sends all alert messages to a TCP endpoint.

Create a TICKscript that publishes alert messages to a topic. The TICKscript below sends an alert message to the `cpu` topic any time idle CPU usage drops below 10%.

***cpu\_alert.tick***

```js
stream
  |from()
    .measurement('cpu')
  |alert()
    .crit(lambda: "usage_idle" < 10)
    .message('Hey, check your CPU')
    .topic('cpu')
```

Add and enable the TICKscript:

```bash
kapacitor define cpu_alert -tick cpu_alert.tick
kapacitor enable cpu_alert
```

Create a handler file that subscribes to the `cpu` topic and uses the TCP event handler to send alert data to a TCP endpoint.

***tcp\_cpu\_handler.yaml***

```yaml
id: tcp-cpu-alert
topic: cpu
kind: tcp
options:
  address: 127.0.0.1:7777
```

Add the handler:

```bash
kapacitor define-topic-handler tcp_cpu_handler.yaml
```