Subscribe to topics

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Create an SNS topic, publish to it from a function, and subscribe to it with a function and a queue.

sst.config.ts

const queue = new sst.aws.Queue("MyQueue");
queue.subscribe("subscriber.handler");

const topic = new sst.aws.SnsTopic("MyTopic");
topic.subscribe("MySubscriber1", "subscriber.handler", {});
topic.subscribeQueue("MySubscriber2", queue.arn);

const app = new sst.aws.Function("MyApp", {
  handler: "publisher.handler",
  link: [topic],
  url: true,
});

subscriber.ts

import type { SQSEvent } from "aws-lambda";

export const handler = async (event: SQSEvent) => {
  console.log(event);
  return "ok";
};

publisher.ts

import { Resource } from "sst";
import { SNSClient, PublishCommand } from "@aws-sdk/client-sns";
const client = new SNSClient();

export const handler = async (event) => {
  await client.send(
    new PublishCommand({
      TargetArn: Resource.MyTopic.arn,
      Message: JSON.stringify({ foo: "bar" }),
      MessageAttributes: { foo: { DataType: "String", StringValue: "bar" } },
    })
  );

  return {
    statusCode: 200,
    body: JSON.stringify({ status: "sent" }, null, 2),
  };
};

View the full example.