# ParseKeyValueProperty

This processor parses a specified field in the original log event into key-value pairs.

For more information about this processor including examples, see parseKeyValue in the CloudWatch Logs User Guide.

- Source: [`aws-logs/lib/transformer.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/aws-logs/lib/transformer.ts#L262)
- Type last changed: v2.207.0 · 24 Jul 2025

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import { aws_logs as logs } from 'aws-cdk-lib';
const parseKeyValueProperty: logs.ParseKeyValueProperty = {
  destination: 'destination',
  fieldDelimiter: logs.KeyValuePairDelimiter.AMPERSAND,
  keyPrefix: 'keyPrefix',
  keyValueDelimiter: logs.KeyValueDelimiter.EQUAL,
  nonMatchValue: 'nonMatchValue',
  overwriteIfExists: false,
  source: 'source',
};
```

## Properties

- `destination`: string — The destination field to put the extracted key-value pairs into.

  **Default:** Places at the root of the JSON input.

- `fieldDelimiter`: [KeyValuePairDelimiter](/cdk/api/v2/docs/aws-cdk-lib.aws_logs.KeyValuePairDelimiter.html) = KeyValuePairDelimiter.AMPERSAND — The field delimiter string that is used between key-value pairs in the original log events.

- `keyPrefix`: string — If you want to add a prefix to all transformed keys, specify it here.

  **Default:** No prefix is added to the keys.

- `keyValueDelimiter`: [KeyValueDelimiter](/cdk/api/v2/docs/aws-cdk-lib.aws_logs.KeyValueDelimiter.html) = KeyValueDelimiter.EQUAL — The delimiter string to use between the key and value in each pair in the transformed log event.

- `nonMatchValue`: string — A value to insert into the value field in the result, when a key-value pair is not successfully split.

  **Default:** No values is inserted when split is not successful.

- `overwriteIfExists`: boolean = false — Specifies whether to overwrite the value if the destination key already exists.

- `source`: string = '@message' — Path to the field in the log event that will be parsed.

  Use dot notation to access child fields.