# HTTP/HTTPS notification JSON format
<a name="http-notification-json"></a>

When Amazon SNS sends a notification to a subscribed HTTP or HTTPS endpoint, the POST message sent to the endpoint has a message body that contains a JSON document with the following name-value pairs.

**`Type`**  
The type of message. For a notification, the type is `Notification`.

**`MessageId`**  
A Universally Unique Identifier (UUID), unique for each message published. For a notification that Amazon SNS resends during a retry, the message ID of the original message is used.

**`TopicArn`**  
The Amazon Resource Name (ARN) for the topic that this message was published to.

**`Subject`**  
The `Subject` parameter specified when the notification was published to the topic.  
This is an optional parameter. If no `Subject` was specified, then this name-value pair does not appear in this JSON document.

**`Message`**  
The `Message` value specified when the notification was published to the topic.

**`Timestamp`**  
The time (GMT) when the notification was published.

**`SignatureVersion`**  
Version of the Amazon SNS signature used.  
+ If the `SignatureVersion` is **1**, `Signature` is a Base64-encoded `SHA1withRSA` signature of the `Message`, `MessageId`, `Subject` (if present), `Type`, `Timestamp`, and `TopicArn` values.
+ If the `SignatureVersion` is **2**, `Signature` is a Base64-encoded `SHA256withRSA` signature of the `Message`, `MessageId`, `Subject` (if present), `Type`, `Timestamp`, and `TopicArn` values.

**`Signature`**  
Base64-encoded `SHA1withRSA` or `SHA256withRSA` signature of the `Message`, `MessageId`, `Subject` (if present), `Type`, `Timestamp`, and `TopicArn` values.

**`SigningCertURL`**  
The URL to the certificate that was used to sign the message.

**`UnsubscribeURL`**  
A URL that you can use to unsubscribe the endpoint from this topic. If you visit this URL, Amazon SNS unsubscribes the endpoint and stops sending notifications to this endpoint.

**`MessageAttributes`**  
Amazon SNS represents the message attributes that you attached to the published message as a JSON object. This object maps each attribute name to an object with a `Type` and a `Value`. For more information about attribute types, see [Amazon SNS message attributes](sns-message-attributes.md).  
`MessageAttributes` is optional. If the published message has no message attributes, this name-value pair does not appear in this JSON document.

The following HTTP POST message is an example of a `Notification` message to an HTTP endpoint.

```
POST / HTTP/1.1
x-amz-sns-message-type: Notification
x-amz-sns-message-id: 22b80b92-fdea-4c2c-8f9d-bdfb0c7bf324
x-amz-sns-topic-arn: arn:aws:sns:us-west-2:123456789012:MyTopic
x-amz-sns-subscription-arn: arn:aws:sns:us-west-2:123456789012:MyTopic:c9135db0-26c4-47ec-8998-413945fb5a96
Content-Length: 773
Content-Type: text/plain; charset=UTF-8
Host: myhost.example.com
Connection: Keep-Alive
User-Agent: Amazon Simple Notification Service Agent

{
  "Type" : "Notification",
  "MessageId" : "22b80b92-fdea-4c2c-8f9d-bdfb0c7bf324",
  "TopicArn" : "arn:aws:sns:us-west-2:123456789012:MyTopic",
  "Subject" : "My First Message",
  "Message" : "Hello world!",
  "Timestamp" : "2012-05-02T00:54:06.655Z",
  "SignatureVersion" : "1",
  "Signature" : "EXAMPLEw6JRN...",
  "SigningCertURL" : "https://sns.us-west-2.amazonaws.com/SimpleNotificationService-f3ecfb7224c7233fe7bb5f59f96de52f.pem",
  "UnsubscribeURL" : "https://sns.us-west-2.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:us-west-2:123456789012:MyTopic:c9135db0-26c4-47ec-8998-413945fb5a96"
  }
```