AWS Lambda Setup from Scratch: TypeScript Without any Frameworks

TypeScript is a popular choice for AWS Lambda thanks to its strong community support with NPM packages, widespread adoption among developers, and the Node runtime being performant on AWS Lambda.

In this tutorial, I'll show you how to set up AWS Lambda with Typescript and ESBuild in under 2 minutes without any frameworks.

Why ESBuild?

• Best performance
  ESBuild is one of the fastest JavaScript and TypeScript bundlers available, significantly reducing build times compared to alternatives like Webpack or Parcel.
• Tree-Shaking & Minification
  It efficiently removes unused code and optimizes your Lambda package size, leading to faster cold starts and lower execution costs.
• First-Class TypeScript Support
  ESBuild compiles TypeScript natively without requiring additional transpilers like tsc, streamlining the build process.

Step 1: Create a New Directory for Your Project

mkdir -p typescript-lambda/src && cd typescript-lambda

Step 2: Initialize a package.json with npm init

npm init -y

Step 3: Install Required npm packages

npm i typescript @types/node@latest esbuild esbuild-node-externals @types/aws-lambda -D

Step 4: Initialize a tsconfig.json file

npx tsc --init --target ES2020 --module commonjs --declaration false --esModuleInterop --forceConsistentCasingInFileNames --outDir ./dist --strict --skipLibCheck --baseUrl "src"

Step 5: Create the Lambda

import { Context } from 'aws-lambda';
import { LambdaEvent } from '@interfaces/lambdaEvent';

export const handler = async (event: LambdaEvent, context: Context) => {
  const { functionName } = context;

  const { action, data } = event;

  console.log(
    `Lambda event received for ${functionName}. action=${action}, data=${data}`,
  );
};

export interface LambdaEvent {
  action: string;
  data: string;
}

Step 6: Create a Bash Script to Build and Zip the Lambda

#!/bin/bash

# clear previous zip
rm lambda.zip

# npm install
npm i

# build
npm run build

# only install production dependencies for production build
npm install --omit=dev

# zip index.js
cd dist && zip -r ../lambda.zip index.js && cd ..

# zip node_modules
zip -r lambda.zip node_modules/ -g

# install all dependencies again to ensure vs.code resolves them
npm i

echo "✅ build completed. zipped lambda.zip"

sudo chmod +x build.sh

Step 7: Create an Execution Role for the Lambda in AWS

aws iam create-role \
  --role-name TypescriptLambdaExecutionRole \
  --assume-role-policy-document '{
    "Version": "2012-10-17",
    "Statement": [
      {
        "Effect": "Allow",
        "Principal": {
          "Service": "lambda.amazonaws.com"
        },
        "Action": "sts:AssumeRole"
      }
    ]
  }'

aws iam attach-role-policy \
  --role-name TypescriptLambdaExecutionRole \
  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

Step 8: Get the Execution Role ARN

aws iam get-role --role-name TypescriptLambdaExecutionRole --query "Role.Arn" --output text

Step 9: Deploy the Lambda to AWS

aws lambda create-function \
  --function-name TypescriptLambda \
  --runtime nodejs20.x \
  --role arn:aws:iam::1234567-your-account-id:role/TypescriptLambdaExecutionRole \
  --handler index.handler \
  --zip-file fileb://lambda.zip \
  --region us-east-1

Step 10: Invoke The Lambda on the AWS Console

{
    "action": "greet",
    "data": "hello"
}

Related Posts

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Resources

• AWS Lambda Developer Guide
• ESBuild
• Typescript