Amazon CloudWatch Events
API Reference (API Version 2015-10-07)


Tests whether an event pattern matches the provided event.

Note: Most services in AWS treat : or / as the same character in Amazon Resource Names (ARNs). However, CloudWatch Events uses an exact match in event patterns and rules. Be sure to use the correct ARN characters when creating event patterns so that they match the ARN syntax in the event you want to match.

Request Syntax

   "Event": "string",
   "EventPattern": "string"

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.


The event in the JSON format to test against the event pattern.

Type: String

Required: Yes


The event pattern you want to test.

Type: String

Length Constraints: Maximum length of 2048.

Required: Yes

Response Syntax

   "Result": boolean

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.


Indicates whether the event matches the event pattern.

Type: Boolean


For information about the errors that are common to all actions, see Common Errors.


This exception occurs due to unexpected causes.

HTTP Status Code: 500


The event pattern is invalid.

HTTP Status Code: 400


Tests that a given event matches a given event pattern.

The following is an example of a TestEventPattern request and response.

Sample Request

Host: events.<region>.<domain>
x-amz-Date: <Date>
Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=content-type;date;host;user-agent;x-amz-date;x-amz-target;x-amzn-requestid, Signature=<Signature>
User-Agent: <UserAgentString>
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Connection: Keep-Alive 
X-Amz-Target: AWSEvents.TestEventPattern

    "EventPattern": "{\"source\": [\"com.mycompany.myapp\"]}",
    "Event": "{\"id\": \"e00c66cb-fe7a-4fcc-81ad-58eb60f5d96b\", \"detail-type\": \"myDetailType\", \"source\": \"com.mycompany.myapp\", \"account\": \"123456789012\", \"time\": \"2016-01-10T01:29:23Z\", \"region\": \"us-east-1\", \"resources\": [\"resource1\",  \"resource2\"], \"detail\": {{\"key1\": \"value1\", \"key2\": \"value2\"}}"

Sample Response

HTTP/1.1 200 OK
x-amzn-RequestId: <RequestId>
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Date: <Date>

    "Result": true