> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chronosphere.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Encode CSV

export const entity_0 = "encode CSV processing rule"

The encode CSV [processing rule](/ingest/pipeline/processing-rules) transforms log data
from JSON to CSV format. The resulting output includes both the original JSON data
and a string of comma-separated values assigned to a key you specify.

## Configuration parameters

Use the parameters in this section to configure the {entity_0}. The
Telemetry Pipeline web interface uses the items in the **Name** column to
describe these parameters. [Pipeline configuration files](/ingest/pipeline/v2/configure/config-files)
use the items in the **Key** column as YAML keys.

| Name                | Key       | Description                                                                                                                                                                                                                                                                                                     | Default       |
| ------------------- | --------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------- |
| **Source key**      | `src`     | Required. The key of the JSON data to transform. This JSON data must be either an array of strings or an object that contains key/value pairs.                                                                                                                                                                  | *none*        |
| **Destination key** | `dst`     | Required. The key to store your string of comma-separated values. If a key with this name already exists, the encode CSV rule will overwrite it.                                                                                                                                                                | `encoded_csv` |
| **Header**          | `header`  | The header row for your comma-separated values. If **Source key** is a JSON object that contains key/value pairs, set this value to a list of the names of each key. Items in this list must be separated by commas and should match the name and order that the keys appear within their original JSON object. | *none*        |
| **Comment**         | `comment` | A custom note or description of the rule's function. This text is displayed next to the rule's name in the **Actions** list in the processing rules interface.                                                                                                                                                  | *none*        |

## Examples

Using the encode CSV rule lets you turn JSON data into comma-separated values that
can be fed into databases and spreadsheet software.

### Array of strings

If your JSON data is an array of strings, don't use the **Header** parameter.
For example, given this sample JSON data:

```json theme={null}
{"ingredients":["pasta","tomato","basil","olive oil","parmesan"]}
{"ingredients":["potatoes","butter","salt","chives","sour cream","bacon bits","shredded cheese"]}
{"ingredients":["cereal","milk"]}
{"ingredients":["bread","mayo","mustard","lettuce","tomato","deli meat","pickle"]}
```

A processing rule with the **Source key** value `ingredients` and the **Destination key**
value `encoded_csv` returns the following result:

```json theme={null}
{"encoded_csv":"pasta,tomato,basil,olive oil,parmesan\n","ingredients":["pasta","tomato","basil","olive oil","parmesan"]}
{"encoded_csv":"potatoes,butter,salt,chives,sour cream,bacon bits,shredded cheese\n","ingredients":["potatoes","butter","salt","chives","sour cream","bacon bits","shredded cheese"]}
{"encoded_csv":"cereal,milk\n","ingredients":["cereal","milk"]}
{"encoded_csv":"bread,mayo,mustard,lettuce,tomato,deli meat,pickle\n","ingredients":["bread","mayo","mustard","lettuce","tomato","deli meat","pickle"]}
```

This rule retained the original `ingredients` array and created a new key called
`encoded_csv` to store the converted comma-separated values.

### Key/value pairs

If your JSON data is an object that contains key/value pairs, you must use the
**Header** parameter. For example, given this sample website log data:

```json theme={null}
{"log":{"timestamp":"2023-03-28T09:08:41.64283645Z","user_id":"3","action":"purchase","page_id":"30"}}
{"log":{"timestamp":"2023-03-28T09:08:42.643343109Z","user_id":"4","action":"purchase","page_id":"10"}}
{"log":{"timestamp":"2023-03-28T09:08:48.643600498Z","user_id":"1","action":"click","page_id":"50"}}
{"log":{"timestamp":"2023-03-28T09:08:50.643773688Z","user_id":"5","action":"purchase","page_id":"40"}}
{"log":{"timestamp":"2023-03-28T09:08:51.643932272Z","user_id":"1","action":"purchase","page_id":"30"}}
{"log":{"timestamp":"2023-03-28T09:08:56.644080944Z","user_id":"2","action":"click","page_id":"40"}}
{"log":{"timestamp":"2023-03-28T09:09:03.64425954Z","user_id":"3","action":"click","page_id":"30"}}
{"log":{"timestamp":"2023-03-28T09:09:03.644317046Z","user_id":"1","action":"view","page_id":"20"}}
{"log":{"timestamp":"2023-03-28T09:09:10.64447719Z","user_id":"2","action":"purchase","page_id":"50"}}
{"log":{"timestamp":"2023-03-28T09:09:17.644810963Z","user_id":"2","action":"view","page_id":"10"}}
{"log":{"timestamp":"2023-03-28T09:09:20.644994805Z","user_id":"1","action":"view","page_id":"50"}}
```

A processing rule with the **Source key** value `log`, the **Destination key**
value `encoded_csv`, and the **Header** value `timestamp,user_id,action,page_id`
returns the following result:

```json theme={null}
{"log":{"page_id":"30","action":"purchase","timestamp":"2023-03-28T09:08:41.64283645Z","user_id":"3"},"encoded_csv":"timestamp,user_id,action,page_id\n2023-03-28T09:08:41.64283645Z,3,purchase,30\n"}
{"log":{"page_id":"10","action":"purchase","timestamp":"2023-03-28T09:08:42.643343109Z","user_id":"4"},"encoded_csv":"2023-03-28T09:08:42.643343109Z,4,purchase,10\n"}
{"log":{"page_id":"50","action":"click","timestamp":"2023-03-28T09:08:48.643600498Z","user_id":"1"},"encoded_csv":"2023-03-28T09:08:48.643600498Z,1,click,50\n"}
{"log":{"page_id":"40","action":"purchase","timestamp":"2023-03-28T09:08:50.643773688Z","user_id":"5"},"encoded_csv":"2023-03-28T09:08:50.643773688Z,5,purchase,40\n"}
{"log":{"page_id":"30","action":"purchase","timestamp":"2023-03-28T09:08:51.643932272Z","user_id":"1"},"encoded_csv":"2023-03-28T09:08:51.643932272Z,1,purchase,30\n"}
{"log":{"page_id":"40","action":"click","timestamp":"2023-03-28T09:08:56.644080944Z","user_id":"2"},"encoded_csv":"2023-03-28T09:08:56.644080944Z,2,click,40\n"}
{"log":{"page_id":"30","action":"click","timestamp":"2023-03-28T09:09:03.64425954Z","user_id":"3"},"encoded_csv":"2023-03-28T09:09:03.64425954Z,3,click,30\n"}
{"log":{"page_id":"20","action":"view","timestamp":"2023-03-28T09:09:03.644317046Z","user_id":"1"},"encoded_csv":"2023-03-28T09:09:03.644317046Z,1,view,20\n"}
{"log":{"page_id":"50","action":"purchase","timestamp":"2023-03-28T09:09:10.64447719Z","user_id":"2"},"encoded_csv":"2023-03-28T09:09:10.64447719Z,2,purchase,50\n"}
{"log":{"page_id":"10","action":"view","timestamp":"2023-03-28T09:09:17.644810963Z","user_id":"2"},"encoded_csv":"2023-03-28T09:09:17.644810963Z,2,view,10\n"}
{"log":{"page_id":"50","action":"view","timestamp":"2023-03-28T09:09:20.644994805Z","user_id":"1"},"encoded_csv":"2023-03-28T09:09:20.644994805Z,1,view,50\n"}
```

This rule retained the original `log` object and created a new key called `encoded_csv`
to store the converted comma-separated values. Additionally, the first instance
of `encoded_csv` contains a header row, which is also separated by commas.

## Related rules

For a processing rule with the opposite effect, see
[decode CSV](/ingest/pipeline/processing-rules/decode-csv).