Subscribe a Lambda function to receive notifications from an Amazon SNS topic using an Amazon SDK - Amazon Simple Notification Service
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Subscribe a Lambda function to receive notifications from an Amazon SNS topic using an Amazon SDK

The following code examples show how to subscribe a Lambda function so it receives notifications from an Amazon SNS topic.

C++
SDK for C++
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

/** * Subscribe an AWS Lambda endpoint to a topic - demonstrates how to initiate a subscription to an Amazon SNS topic with delivery * to an AWS Lambda function. * * NOTE: You must first configure AWS Lambda to run this example. * See https://docs.amazonaws.cn/en_us/lambda/latest/dg/with-sns-example.html for more information. * * <protocol_value> set to "lambda" provides delivery of JSON-encoded message to an AWS Lambda function * (see https://docs.aws.amazon.com/sns/latest/api/API_Subscribe.html for available protocols). * <topic_arn_value> can be obtained from run_list_topics executable and includes the "arn:" prefix. * <lambda_function_arn> is the ARN of an AWS Lambda function. */ int main(int argc, char ** argv) { if (argc != 4) { std::cout << "Usage: subscribe_lamda <protocol_value=lambda> <topic_arn_value>" " <lambda_function_arn>" << std::endl; return 1; } Aws::SDKOptions options; Aws::InitAPI(options); { Aws::SNS::SNSClient sns; Aws::String protocol = argv[1]; Aws::String topic_arn = argv[2]; Aws::String endpoint = argv[3]; Aws::SNS::Model::SubscribeRequest s_req; s_req.SetTopicArn(topic_arn); s_req.SetProtocol(protocol); s_req.SetEndpoint(endpoint); auto s_out = sns.Subscribe(s_req); if (s_out.IsSuccess()) { std::cout << "Subscribed successfully " << std::endl; } else { std::cout << "Error while subscribing " << s_out.GetError().GetMessage() << std::endl; } } Aws::ShutdownAPI(options); return 0; }
  • For API details, see Subscribe in Amazon SDK for C++ API Reference.

Java
SDK for Java 2.x
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

public static String subLambda(SnsClient snsClient, String topicArn, String lambdaArn) { try { SubscribeRequest request = SubscribeRequest.builder() .protocol("lambda") .endpoint(lambdaArn) .returnSubscriptionArn(true) .topicArn(topicArn) .build(); SubscribeResponse result = snsClient.subscribe(request); return result.subscriptionArn(); } catch (SnsException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } return ""; }
  • For API details, see Subscribe in Amazon SDK for Java 2.x API Reference.

JavaScript
SDK for JavaScript (v3)
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

Create the client in a separate module and export it.

import { SNSClient } from "@aws-sdk/client-sns"; // Set the AWS Region. const REGION = "REGION"; //e.g. "us-east-1" // Create SNS service object. const snsClient = new SNSClient({ region: REGION }); export { snsClient };

Import the SDK and client modules and call the API.

// Import required AWS SDK clients and commands for Node.js import {SubscribeCommand } from "@aws-sdk/client-sns"; import {snsClient } from "./libs/snsClient.js"; // Set the parameters const params = { Protocol: "lambda" /* required */, TopicArn: "TOPIC_ARN", //TOPIC_ARN Endpoint: "LAMBDA_FUNCTION_ARN", //LAMBDA_FUNCTION_ARN }; const run = async () => { try { const data = await snsClient.send(new SubscribeCommand(params)); console.log("Success.", data); return data; // For unit tests. } catch (err) { console.log("Error", err.stack); } }; run();
Kotlin
SDK for Kotlin
Note

This is prerelease documentation for a feature in preview release. It is subject to change.

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

suspend fun subLambda(topicArnVal: String?, lambdaArn: String?) { val request = SubscribeRequest { protocol = "lambda" endpoint = lambdaArn returnSubscriptionArn = true topicArn = topicArnVal } SnsClient { region = "us-east-1" }.use { snsClient -> val result = snsClient.subscribe(request) println(" The subscription Arn is ${result.subscriptionArn}") } }
  • For API details, see Subscribe in Amazon SDK for Kotlin API reference.

For a complete list of Amazon SDK developer guides and code examples, see Using Amazon SNS with an Amazon SDK. This topic also includes information about getting started and details about previous SDK versions.