How to Create a Serverless API Using AWS Lambda and Node.js with TypeScript and Express.js

In this article, we’ll create an application using Node.js with TypeScript and Express.js, where a serverless API will be implemented and deployed on the AWS Lambda service. Getting started Create and configure an account on AWS Lambda AWS Lambda is a service that lets you run code for virtually any type of application without provisioning or managing servers or clusters. Let's create and configure the account. Access the site and click on the button . 1. https://aws.amazon.com/lambda/ Get Started with AWS Lambda Now click on the option “ , fill in the field “ and click on the button “ . 2. Root user” Root user email address” Next” Note: If you don't have an Amazon account, do steps 1 to 9 of the post in the session . Authentication using the Amazon Cognito to an Angular application Create and configure the account on the Amazon Cognito Next, we will fill in the field and click on the button . 3. Password Sign in After accessing the account, we will type in the search field and click on the option . 4. aim AIM Now, we will click on the menu . 5. Users Next, we will click on the button . 6. Add users After accessing the screen for adding users, we will fill in the field and click on the button . 7. User name Next Now we will click on the option Click on the item and click on the button . 8. Attach policies directly. AdministratorAccess Next Next, we will click on the button . 9. Create user After creating the user, we will click on the link with the user name. 10. Now, we will click on the tab and click on the button . 11. Security credentials Create access key Next, we will click on the option and click on the button . 12. Command Line Interface (CLI) Next Then, we will click on the button . 13. Create access key After creating the access keys, we will copy the keys and because the keys will be used in the command line and click on the button . 14. Access key Secret access key Create access key Ready! Your account was created and configured, and the keys were created. 15. Create the Node.js application Node.js is open-source, cross-platform software that runs JavaScript code on the server. It is based on Google's V8 JavaScript interpreter. Let's create the application. We will create the application folder. 1. mkdir nodejs-aws-lambda cd nodejs-aws-lambda Now, we will create the file . The option allows the file to be created without the questions, such as application name, and version, among others. 2. package.json -y npm init -y Next, we will install the application dependencies and . 3. express serverless-http npm install express serverless-http After installing the application dependencies, we will install the development dependencies , and . 4. ts-node typescript @types/express npm install rimraf ts-node typescript @types/express --save-dev Now, we will create the TypeScript configuration file . 5. tsconfig.json ./node_modules/.bin/tsc --init Next, we will configure the TypeScript file . 6. tsconfig.json { "compilerOptions": { "target": "ESNEXT", "module": "commonjs", "outDir": "./dist", "esModuleInterop": true, "forceConsistentCasingInFileNames": true, "strict": true, "skipLibCheck": true }, "include": [ "src/**/*" ] } After configuring the TypeScript file, we will add the transpilation script in the file . 7. package.json "scripts": { "build": "rimraf dist && tsc" }, Now, we will create the folder , and . 8. src src/routes src/routes/v1 mkdir -p src/routes/v1 Next, we will create the routes file . 9. src/routes/v1/books.ts touch src/routes/v1/books.route.ts After creating the routes file, we will add the routes to the file . 10. src/routes/v1/books.route.ts import { Request, Response, Router } from 'express'; const router = Router(); router.get('/', async (req: Request, res: Response) => { try { res.status(200).json([]); } catch (error) { console.error('An error ocurred:', error); res.status(500).json(error); } }); router.get('/:id', async (req: Request, res: Response) => { try { res.status(200).json({}); } catch (error) { console.error('An error ocurred:', error); res.status(500).json(error); } }); router.post('/', async (req: Request, res: Response) => { try { res.status(201).json({}); } catch (error) { console.error('An error occurred:', error); res.status(500).json(error); } }); router.put('/:id', async (req: Request, res: Response) => { try { res.status(200).json({}); } catch (error) { console.error('An error occurred:', error); res.status(500).json(error); } }); router.delete('/:id', async (req: Request, res: Response) => { try { res.status(200).json({}); } catch (error) { console.error('An error occurred:', error); res.status(500).json(error); } }); export default router; Now, we will create the file with the routes configuration of version 1. 11. src/routes/v1/index.ts touch src/routes/v1/index.ts Next, we will add the routes configuration to the file . 12. src/routes/v1/index.ts import { Router } from 'express'; import books from './books.route'; const router = Router(); router.use('/books', books); export default router; Then, we will create the file with the routes configuration. 13. src/routes/index.ts touch src/routes/index.ts After creating the file with the routes configuration, we will add the routes configuration to the file . 14. src/routes/index.ts import { Router } from 'express'; import v1 from './v1'; const router = Router(); router.use('/v1', v1); export default router; Now, we will create the application file with the Express.js settings. 15. src/app.ts touch src/app.ts Next, we will add the Express.js settings to the file . 16. src/app.ts import express from 'express'; import serverless from 'serverless-http'; import routes from './routes'; const app = express(); app.use(express.json()); app.use('/', routes); app.use((req: express.Request, res: express.Response, next: express.NextFunction) => { res.status(404).send(); }); app.use((err: any, req: express.Request, res: express.Response, next: express.NextFunction) => { res.status(err.status || 500).send(); }); export const handler = serverless(app); After adding the Express.js settings, we will create the Serverless configuration file with the AWS Lambda settings. 17. serverless.yml touch serverless.yml Now, we will add the AWS Lambda settings to the file . 18. serverless.yml service: nodejs-aws-lambda provider: name: aws runtime: nodejs18.x functions: app: handler: dist/app.handler events: - http: ANY / - http: ANY /{proxy+} Next, we will build the application. 19. npm run build > nodejs-aws-lambda@1.0.0 build /home/rodrigokamada/nodejs-aws-lambda > rimraf dist && tsc After building the application, we will install tool. 20. serverless npm install -g serverless Now, we will configure the tool. 21. serverless serverless config credentials --provider aws --key 7YEE7ANQHFDGLZAKIAQR --secret yyyMEboMvA/IXUFI7djIoMRBJ3b0kFQ8p8TN6pKW ✔ Profile "default" has been configured Next, we will deploy the application. 22. serverless deploy Deploying nodejs-aws-lambda to stage dev (us-east-1) ✔ Service deployed to stack nodejs-aws-lambda-dev (56s) endpoints: ANY - https://5imsknki87.execute-api.us-east-1.amazonaws.com/dev ANY - https://5imsknki87.execute-api.us-east-1.amazonaws.com/dev/{proxy+} functions: app: nodejs-aws-lambda-dev-app (853 kB) Monitor Express APIs by route with the Serverless Console: run "serverless --console" After deploying the application, we will confirm if the application was deployed on the AWS Lambda service. We will type in the search field and click on the option . 23. lambda Lambda Now, we will confirm that a was created with the name . 24. function nodejs-aws-lambda-dev-app Ready! The application was created and deployed on AWS Lambda. 25. The application repository is available at . https://github.com/rodrigokamada/nodejs-aws-lambda Test the application on the AWS Lambda service Let's test the application on the AWS Lambda service. Send a request on the route created and the URL provided. 1. curl -s "https://5imsknki87.execute-api.us-east-1.amazonaws.com/dev/v1/books" | jq [ { "id": "ebb3d966-74e4-11ed-8db0-136d663b98e7", "title": "Some Title", "author": "Some Author" } ] Ready! We tested the serverless API deployed on the AWS Lambda service. 2. Conclusion Summarizing what was covered in this article: We created an account on Amazon Web Services (AWS). We created the access keys on Amazon Web Services (AWS). We created a Node.js application. We created the routes in the Node.js application using Express.js. We tested the Node.js application on the AWS Lambda service. You can use this article to provide an API in the cloud without having to manage servers or clusters. Thank you for reading and I hope you enjoyed the article! This tutorial was posted on my in Portuguese. blog