Lambda event filter for Json array

Question

In the documentation https://docs.aws.amazon.com/lambda/latest/dg/invocation-eventfiltering.html#filtering-syntax
it is only mention "Weather": [ { "anything-but": [ "Raining" ] } ]

What I am need is to filter if the array contains a specific value. 
Example json
{
	"MyKey": "Value",
	"Number": 12,
	"References": [
		{
			"Key1": 14
		},
		{
			"Key2": 14
		}
	]
}

What would be the filter syntax to check if "Key1" exists ?

Answer

In EventBridge, your custom payload is always included in the "detail" field, so your actual event will look like:
```
{
  "detail-type": "MyCustomEvent",
  "source": "aws.partner/salesforce.com/xxxxxxxxxxxx/xxxxxxxxxxx",
  "account": "12345678921",
  "time": "2022-04-06T20:24:01Z",
  "resources": [],
  "detail": {
    "MyKey": "Value",
    "Number": 12,
    "References": [{
      "Key1": 14
    }, {
      "Key2": 14
    }]
  }
}
```

Your rule should look like this:
```
{
  "detail": {
    "References": {
      "Key2": [14]
    }
  }
}
```

Lambda event filter for Json array

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