# Type converter

{% hint style="info" %}
**Supported event types:** `logs`
{% endhint %}

![](https://static.scarf.sh/a.png?x-pxid=8984f540-d95a-462b-8a08-09f72f5fab63)

The *Type converter* filter plugin converts data types and appends new key-value pairs.

You can use this filter in combination with plugins which expect incoming string value. For example, [Grep](https://docs.fluentbit.io/manual/4.2/data-pipeline/filters/grep) and [Modify](https://docs.fluentbit.io/manual/4.2/data-pipeline/filters/modify).

## Configuration parameters

The plugin supports the following configuration parameters. It needs four parameters.

```
<config_parameter> <src_key_name> <dst_key_name> <dst_data_type>`
```

`dst_data_type` allows `int`, `uint`, `float`, and `string`. For example, `int_key id id_str string`.

| Key         | Description                                       |
| ----------- | ------------------------------------------------- |
| `float_key` | This parameter is for a float source.             |
| `int_key`   | This parameter is for an integer source.          |
| `str_key`   | This parameter is for a string source.            |
| `uint_key`  | This parameter is for an unsigned integer source. |

## Get started

To start filtering records, you can run the filter from the command line or through the configuration file.

This is a sample `in_mem` record to filter.

```
{"Mem.total"=>1016024, "Mem.used"=>716672, "Mem.free"=>299352, "Swap.total"=>2064380, "Swap.used"=>32656, "Swap.free"=>2031724}
```

The plugin outputs `uint` values and `filter_type_converter` converts them into string type.

### Convert `uint` to string

{% tabs %}
{% tab title="fluent-bit.yaml" %}

```yaml
pipeline:
  inputs:
    - name: mem

  filters:
    - name: type_converter
      match: '*'
      uint_key:
        - Mem.total Mem.total_str string
        - Mem.used  Mem.used_str  string
        - Mem.free  Mem.free_str  string

  outputs:
    - name: stdout
      match: '*'
```

{% endtab %}

{% tab title="fluent-bit.conf" %}

```
[INPUT]
  Name mem

[FILTER]
  Name               type_converter
  Match              *
  Uint_Key Mem.total Mem.total_str string
  Uint_Key Mem.used  Mem.used_str  string
  Uint_Key Mem.free  Mem.free_str  string

[OUTPUT]
  Name  stdout
  Match *
```

{% endtab %}
{% endtabs %}

You can also run the filter from command line.

```shell
fluent-bit -i mem -o stdout -F type_converter -p 'uint_key=Mem.total Mem.total_str string' -p 'uint_key=Mem.used Mem.used_str string' -p 'uint_key=Mem.free Mem.free_str string' -m '*'
```

The output will be

```
[0] mem.0: [1639915154.160159749, {"Mem.total"=>8146052, "Mem.used"=>4513564, "Mem.free"=>3632488, "Swap.total"=>1918356, "Swap.used"=>0, "Swap.free"=>1918356, "Mem.total_str"=>"8146052", "Mem.used_str"=>"4513564", "Mem.free_str"=>"3632488"}]
```