How to Test AWS SNS HTTP Endpoints

How AWS SNS HTTP Delivery Works

Amazon Simple Notification Service (SNS) delivers messages to HTTP/HTTPS endpoints by sending POST requests with a JSON body. The delivery flow is two-phase: SNS first verifies that your endpoint is reachable and willing to accept notifications, then starts delivering actual messages.

Every SNS message has a Type field that tells you which phase you are in. The three types you will encounter are:

The SubscriptionConfirmation message contains a SubscribeURL field — a pre-signed AWS URL. Your endpoint must make a GET request to that URL to activate the subscription. Until this is done, SNS will not deliver any Notification messages, and the subscription will remain in a Pending confirmation state in the AWS Console.

Requex captures the SubscriptionConfirmation payload so you can copy the SubscribeURL and confirm manually — no code required.

SNS Message Types

Step 1: Generate a Requex Endpoint

Open requex.me. A unique HTTPS webhook URL is generated automatically. Copy it from the dashboard:

https://requex.me/hook/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

SNS requires a valid HTTPS endpoint — Requex satisfies this requirement out of the box. You do not need a running server, an AWS account, or any local setup.

Step 2: Subscribe to an SNS Topic

In the AWS Console, navigate to SNS and subscribe your Requex endpoint to a topic:

1. Go to AWS Console → SNS → Topics.
2. Select the topic you want to test (or create a new one).
3. Click Create subscription.
4. Set Protocol to HTTPS.
5. Paste your Requex URL into the Endpoint field.
6. Leave Enable raw message delivery off for now — the default JSON envelope is easier to inspect.
7. Click Create subscription.

The subscription status will show Pending confirmation. SNS immediately sends the SubscriptionConfirmation message to your Requex URL — you should see it appear in the dashboard within a few seconds.

Step 3: Confirm the Subscription

In Requex, click the captured SubscriptionConfirmation request. Find the SubscribeURL field in the JSON body:

{
  "Type": "SubscriptionConfirmation",
  "MessageId": "165545c9-2a5c-4b4d-bc5c-a5caab18d4b0",
  "Token": "2336412f37...",
  "TopicArn": "arn:aws:sns:us-east-1:123456789012:MyTopic",
  "Message": "You have chosen to subscribe to the topic...",
  "SubscribeURL": "https://sns.us-east-1.amazonaws.com/?Action=ConfirmSubscription&TopicArn=arn:aws:sns:us-east-1:123456789012:MyTopic&Token=2336412f37...",
  "Timestamp": "2026-04-05T10:00:00.000Z",
  "SignatureVersion": "1",
  "Signature": "EXAMPLEpH+DcEwjAPg8O...",
  "SigningCertURL": "https://sns.us-east-1.amazonaws.com/SimpleNotificationService-abc123.pem"
}

Copy the entire SubscribeURL value and open it in your browser. AWS responds with an XML confirmation. Go back to the AWS Console — the subscription status should now show Confirmed.

Step 4: Publish a Test Message

Now that the subscription is confirmed, publish a message to the topic to see a real Notification delivery:

1. In the AWS Console, go to SNS → Topics → [your topic].
2. Click Publish message.
3. Enter a subject and message body (e.g., {"event": "test", "value": 42}).
4. Click Publish message.

The notification appears in Requex within seconds. The Notification message looks like:

{
  "Type": "Notification",
  "MessageId": "95df01b4-ee98-5cb9-9903-4c221d41eb5e",
  "TopicArn": "arn:aws:sns:us-east-1:123456789012:MyTopic",
  "Subject": "Test notification",
  "Message": "{"event": "test", "value": 42}",
  "Timestamp": "2026-04-05T10:05:00.000Z",
  "SignatureVersion": "1",
  "Signature": "EXAMPLEpH+DcEwjAPg8O...",
  "SigningCertURL": "https://sns.us-east-1.amazonaws.com/SimpleNotificationService-abc123.pem",
  "UnsubscribeURL": "https://sns.us-east-1.amazonaws.com/?Action=Unsubscribe&..."
}

Note that the Message field is a JSON-encoded string by default. Your handler will need to JSON.parse(body.Message) to access the inner payload.

SNS Message Signing

AWS signs every SNS message to allow your endpoint to verify authenticity. The signature-related fields in each message are:

To verify the signature in production, use the official AWS SDK helper. Here is a Node.js example:

const { MessageValidator } = require('sns-validator');

const validator = new MessageValidator();

app.post('/webhooks/sns', express.json({ type: 'text/plain' }), (req, res) => {
  validator.validate(req.body, (err, message) => {
    if (err) {
      console.error('SNS signature validation failed:', err);
      return res.status(403).send('Invalid signature');
    }

    switch (message.Type) {
      case 'SubscriptionConfirmation':
        // Auto-confirm by visiting SubscribeURL
        fetch(message.SubscribeURL).then(() => {
          console.log('SNS subscription confirmed');
        });
        break;

      case 'Notification':
        const payload = JSON.parse(message.Message);
        console.log('SNS notification:', payload);
        break;
    }

    res.status(200).send('OK');
  });
});

During development with Requex, you can inspect the raw Signature and SigningCertURL values to confirm that SNS is signing messages correctly before wiring up signature verification in your production code.

Common SNS Webhook Issues