Amazon SNS & Pub/Sub Messaging

1import { SNSClient, PublishCommand } from '@aws-sdk/client-sns';
2
3const sns = new SNSClient({ region: 'us-east-1' });
4
5// Basic publish
6await sns.send(new PublishCommand({
7  TopicArn: 'arn:aws:sns:us-east-1:123456789:OrderEvents',
8  Subject: 'Order Placed',          // used for email subscriptions
9  Message: JSON.stringify({
10    eventType: 'ORDER_PLACED',
11    orderId: 'ORD-001',
12    customerId: 'cust_A',
13    amount: 99.99,
14  }),
15  MessageAttributes: {
16    eventType: {
17      DataType: 'String',
18      StringValue: 'ORDER_PLACED',   // used by filter policies
19    },
20    tier: {
21      DataType: 'String',
22      StringValue: 'premium',
23    },
24  },
25}));

1{
2  "Type": "Notification",
3  "MessageId": "abc-123-def",
4  "TopicArn": "arn:aws:sns:us-east-1:123:OrderEvents",
5  "Subject": "Order Placed",
6  "Message": "{\"eventType\":\"ORDER_PLACED\",\"orderId\":\"ORD-001\"}",
7  "Timestamp": "2024-01-15T10:30:00.000Z",
8  "MessageAttributes": {
9    "eventType": { "Type": "String", "Value": "ORDER_PLACED" }
10  }
11}

1// Subscribe an SQS queue to an SNS topic
2import { SubscribeCommand } from '@aws-sdk/client-sns';
3
4await sns.send(new SubscribeCommand({
5  TopicArn: 'arn:aws:sns:us-east-1:123:FileUploaded',
6  Protocol: 'sqs',
7  Endpoint: 'arn:aws:sqs:us-east-1:123:image-resizer',
8  Attributes: {
9    RawMessageDelivery: 'true',  // delivers Message string directly, not SNS envelope
10  },
11}));

1// Subscription filter policy — only deliver ORDER_PLACED and ORDER_UPDATED events
2// for premium-tier customers with amount > 50
3{
4  "eventType": ["ORDER_PLACED", "ORDER_UPDATED"],
5  "tier": ["premium"],
6  "amount": [{ "numeric": [">", 50] }]
7}

1// Attach filter policy when creating subscription
2await sns.send(new SubscribeCommand({
3  TopicArn: 'arn:aws:sns:us-east-1:123:OrderEvents',
4  Protocol: 'sqs',
5  Endpoint: 'arn:aws:sqs:us-east-1:123:premium-orders',
6  Attributes: {
7    FilterPolicy: JSON.stringify({
8      eventType: ['ORDER_PLACED', 'ORDER_UPDATED'],
9      tier: ['premium'],
10    }),
11    FilterPolicyScope: 'MessageAttributes',  // or 'MessageBody'
12  },
13}));

1// Publishing to FIFO topic
2await sns.send(new PublishCommand({
3  TopicArn: 'arn:aws:sns:us-east-1:123:OrderEvents.fifo',
4  Message: JSON.stringify({ orderId: 'ORD-001', action: 'PLACE' }),
5  MessageGroupId: 'customer-cust_A',          // ordering group
6  MessageDeduplicationId: 'ORD-001-PLACE',    // dedup key
7}));

1# Set a DLQ on an SNS subscription
2aws sns set-subscription-attributes \
3  --subscription-arn arn:aws:sns:us-east-1:123:OrderEvents:sub-abc \
4  --attribute-name RedrivePolicy \
5  --attribute-value '{"deadLetterTargetArn":"arn:aws:sqs:us-east-1:123:sns-dlq"}'

1// Register a device and send a push notification
2import { CreatePlatformEndpointCommand, PublishCommand } from '@aws-sdk/client-sns';
3
4// 1. Register the device token from APNs/FCM
5const { EndpointArn } = await sns.send(new CreatePlatformEndpointCommand({
6  PlatformApplicationArn: 'arn:aws:sns:us-east-1:123:app/APNS/MyApp',
7  Token: 'device-token-from-apns',
8  CustomUserData: JSON.stringify({ userId: 'usr_01' }),
9}));
10
11// 2. Send push notification directly to the device
12await sns.send(new PublishCommand({
13  TargetArn: EndpointArn,
14  MessageStructure: 'json',
15  Message: JSON.stringify({
16    APNS: JSON.stringify({
17      aps: {
18        alert: { title: 'Order Shipped!', body: 'Your order ORD-001 is on the way.' },
19        badge: 1,
20        sound: 'default',
21      },
22    }),
23    default: 'Your order ORD-001 has shipped.',
24  }),
25}));

1{
2  "Version": "2012-10-17",
3  "Statement": [
4    {
5      "Effect": "Allow",
6      "Principal": { "Service": "s3.amazonaws.com" },
7      "Action": "SNS:Publish",
8      "Resource": "arn:aws:sns:us-east-1:123:FileUploaded",
9      "Condition": {
10        "ArnLike": { "aws:SourceArn": "arn:aws:s3:::my-upload-bucket" }
11      }
12    }
13  ]
14}