NPM Package - ESM

Learn how to set up Sentry manually for Lambda functions running in EcmaScript Modules (ESM) using Sentry's AWS Serverless SDK NPM package

In this guide you will learn how to set up the @sentry/aws-serverless SDK for AWS Lambda functions running in EcmaScript Modules (ESM) mode. We recommend starting the SDK automatically via environment variables so that you only have to make minimal code changes to your lambda function. If you need more control over the SDK setup, you can also initialize the SDK in in code.

At this time, this guide shows the only way to use Sentry with ESM lambda functions. You cannot use the Sentry AWS Lambda Layer with ESM. We're working on an ESM lambda layer to provide a simpler setup but need to solve several OpenTelemetry-related limitations first.

Before you begin, make sure you have the following:

  • You have a lambda function that is running in EcmaScript Modules (ESM) mode, using import syntax.
  • You're able to deploy dependencies (i.e. node_modules) alongside your function code to AWS Lambda.

Install the @sentry/aws-serverless SDK using a package manager of your choice:

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npm install @sentry/aws-serverless @sentry/profiling-node

Add the Sentry.wrapHandler wrapper around your function handler to automatically catch errors and performance data:

index.mjs
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import * as Sentry from "@sentry/aws-serverless";

export const handler = Sentry.wrapHandler(async (event, context) => {
  // Your handler code
});

To initialize and configure the SDK, you need to set the following environment variables in your AWS Lambda function configuration:

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NODE_OPTIONS="--import @sentry/aws-serverless/awslambda-auto"
SENTRY_DSN="https://examplePublicKey@o0.ingest.sentry.io/0"
SENTRY_TRACES_SAMPLE_RATE="1.0"

To set environment variables, navigate to your Lambda function, select Configuration, then Environment variables:

That's it - make sure to re-deploy your function and you're all set!

To further customize the SDK setup, you can also manually initialize the SDK in your lambda function. Due to ESM limitations, you need to initialize the SDK in a separate file and load it before your function starts. The benefit of this installation method is that you can fully customize your Sentry SDK setup in a Sentry.init call.

Follow steps 1 and 2 above to install the SDK NPM package in your project.

Create a new file, for example instrument.mjs to initialize the SDK:

instrument.mjs
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import * as Sentry from "@sentry/aws-serverless";
import { nodeProfilingIntegration } from "@sentry/profiling-node";

Sentry.init({
  dsn: "__PUBLIC_DSN__",
  integrations: [nodeProfilingIntegration()],
  // Add Tracing by setting tracesSampleRate and adding integration
  // Set tracesSampleRate to 1.0 to capture 100% of transactions
  // We recommend adjusting this value in production
  tracesSampleRate: 1.0,
  // Set sampling rate for profiling - this is relative to tracesSampleRate
  profilesSampleRate: 1.0,
});

Add the Sentry.wrapHandler wrapper around your function handler to automatically catch errors and performance data:

index.mjs
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import * as Sentry from "@sentry/aws-serverless";

export const handler = Sentry.wrapHandler(async (event, context) => {
  // Your handler code
});

To load the SDK before your function starts, you need to preload the instrumentation.mjs by setting the NODE_OPTIONS environment variable:

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NODE_OPTIONS="--import instrument.mjs"

To set environment variables, navigate to your Lambda function, select Configuration, then Environment variables:

That's it - make sure to re-deploy your function and you're all set!

The v7 @sentry/serverless SDK does not work correctly with ESM-based Lambda functions. Please upgrade to the v8 SDK and follow the instructions above.

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