# NATS

The *NATS* output plugin lets you flush your records into a [NATS Server](https://docs.nats.io/) server endpoint.

## Configuration parameters

| Key       | Description                                                                                                                | Default     |
| --------- | -------------------------------------------------------------------------------------------------------------------------- | ----------- |
| `host`    | The IP address or hostname of the NATS server.                                                                             | `127.0.0.1` |
| `port`    | The TCP port of the target NATS server.                                                                                    | `4222`      |
| `workers` | The number of [workers](/manual/4.0/administration/multithreading.md#outputs) to perform flush operations for this output. | `0`         |

{% hint style="info" %}
To override the default configuration values, this plugin uses the optional Fluent Bit network address format (for example, `nats://host:port`).
{% endhint %}

## Get started

You can get started with the NATS output plugin through the command line. If you use the following command without specifying parameter values, Fluent Bit uses the default values defined in the previous section.

```shell
$ fluent-bit -i cpu -o nats -V -f 5

...
[2016/03/04 10:17:33] [ info] Configuration
flush time     : 5 seconds
input plugins  : cpu
collectors     :
[2016/03/04 10:17:33] [ info] starting engine
cpu[all] all=3.250000 user=2.500000 system=0.750000
cpu[i=0] all=3.000000 user=1.000000 system=2.000000
cpu[i=1] all=3.000000 user=2.000000 system=1.000000
cpu[i=2] all=2.000000 user=2.000000 system=0.000000
cpu[i=3] all=6.000000 user=5.000000 system=1.000000
[2016/03/04 10:17:33] [debug] [in_cpu] CPU 3.25%
...
```

## Data format

For every set of records flushed to a NATS server, Fluent Bit uses the following format:

```
[
  [UNIX_TIMESTAMP, JSON_MAP_1],
  [UNIX_TIMESTAMP, JSON_MAP_2],
  [UNIX_TIMESTAMP, JSON_MAP_N],
]
```

Each record is an individual entity represented in a JSON array that contains a Unix timestamp and a JSON map with a set of key/value pairs. A summarized output of the CPU input plugin will resemble the following:

```json
[
  [1457108504,{"tag":"fluentbit","cpu_p":1.500000,"user_p":1,"system_p":0.500000}],
  [1457108505,{"tag":"fluentbit","cpu_p":4.500000,"user_p":3,"system_p":1.500000}],
  [1457108506,{"tag":"fluentbit","cpu_p":6.500000,"user_p":4.500000,"system_p":2}]
]
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.fluentbit.io/manual/4.0/data-pipeline/outputs/nats.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.