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Tirth Patel
Tirth Patel

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Deploy Node API (Express Typescript) on Vercel

A couple of weeks back, I developed an API in Node based on Typescript. I tried to deploy it on Heroku.

But the process was long and time-consuming. Also, I noticed that Heroku is terminating free accounts from 28 Nov'22. ☚ī¸

Heroku

So I tried to experiment with various other platforms to deploy my Typescript-based Node API. Amon them free, robust, and versatile platform I found is VERCEL. Based on my experience, here are a few simple steps which you can follow and easily deploy Typescript-based Node API on Vercel. 🚀


1) Express + Typescript Boilerplate App ✏ī¸

Create express project with typescript. You can follow the below-mentioned steps to make a boilerplate for the project. (Github repo link is provided at end of article)

  • Initialize node project


    npm init -y
    
  • Install packages (you can use npm/yarn/pnpm)


    yarn add express
    yarn add -D typescript
    yarn add -D @types/node
    yarn add -D @types/express
    yarn add -D nodemon
    yarn add -D ts-node
    
  • Create tsconfig.json
    To work with typescript we need to make tsconfig.json file which will help to compile and build Typescript files in plain JS. Execute below command


    npx tsc --init --rootDir src --outDir build --esModuleInterop --resolveJsonModule --lib es6 --module commonjs --allowJs true --noImplicitAny true
    



Once the file is created you can keep it as is, or cleanup non necessary stuff. Replace content of tsconfig.json with following :


    {
    "compilerOptions": {
        "module": "commonjs",
        "esModuleInterop": true,
        "allowSyntheticDefaultImports": true,
        "target": "es6",
        "noImplicitAny": true,
        "moduleResolution": "node",
        "sourceMap": true,
        "outDir": "dist",
        "baseUrl": ".",
        "paths": {
            "*": ["node_modules/*", "src/types/*"]
        }
    },
    "include": ["./src/**/*"]
    }
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  • Update scripts in package.json


    "start": "nodemon src/index.ts",
    
  • Write express server code : Create file : src/index.ts and paste following code in it
  import express, { Request, Response } from 'express'

  const app = express()
  const port = process.env.PORT || 8080

  app.get('/', (_req: Request, res: Response) => {
    return res.send('Express Typescript on Vercel')
  })

  app.get('/ping', (_req: Request, res: Response) => {
    return res.send('pong 🏓')
  })

  app.listen(port, () => {
    return console.log(`Server is listening on ${port}`)
  })
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  • Spin up server : Run yarn start or npm run start command in terminal to start express serve. You can open browser and go to localhost:8080. API will return response of Express Typescript on Vercel.

2) Initialize git in our project. đŸ“Ĩ

  • Make a .gitignore file in the root of the folder. And add node_modules to it. If .gitignore file exists check that node_modules is added into it.
  • Execute git init in the terminal (from root of project) or you can use VS Code's source control tab to initialize git repository.
  • Connect local repo to remote (github/bitbucket). You can use any of the version control system to publish your repository.

3) Create Vercel project 🗃ī¸

  • Go to vercel.com -> Login
  • Login using the Version control platform you have kept your repository.
  • From the dashboard -> Add new project -> Select your repository -> Deploy

  • Afer deployment you will see something similar to this! 😟

Vercel Error
(ERROR 🚨)

  • Don't worry... Just follow on steps to fix it. 👍

4) Add Vercel config in app ⚙ī¸

  • In the above step, after your fist deploy is completed, you can see that we're not getting Express Typescript on Vercel response from API.
  • To work this as expected, we need to tell Vercel that is a API and you need to serve this as a serverless function.
  • For this, simply we need to add vercel.json file in root of our project. Paste below code in file.
{
    "version": 2,
    "builds": [
        {
            "src": "dist/index.js",
            "use": "@vercel/node",
            "config": { "includeFiles": ["dist/**"] }
        }
    ],
    "routes": [
        {
            "src": "/(.*)",
            "dest": "dist/index.js"
        }
    ]
}
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NOTE: Check your tsconfig.json file. The value against outDir must be kept instead of dist. If your config file has any other value than dist, replace it at either of both places.


5) Add a pre-commit hook 🏷ī¸

  • Vercel requires plain JS source files instead of Typescript. In order to do this, we need to build the project before committing and send compiled JS files so that Vercel can parse those files and serve the API.

  • Install pre-commit and rimraf package :


  yarn add -D pre-commit
  yarn add -D rimraf
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  • Modify scripts field in package.json file as follows:
  "scripts": {
  "start": "nodemon src/index.ts",
  "build": "rimraf dist && tsc",
  "ts.check": "tsc --project tsconfig.json",
  "add-build": "git add dist",
  "test": "echo \"Error: no test specified\" && exit 1"
  },
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  • Add new field pre-commit field in package.json :
  "pre-commit": [
      "ts.check",
      "build",
      "add-build"
  ]
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  • What this will do? → Whenever you will commit, the commands written in pre-commit will be executed. It will check Typescript errors, build the project and add build folder to the staged changes. (If you opt for manual build, don't forget to run build command to start build.)

5) Re-Deploy and Re-Check API 🔁

  • Commit the changes you have made and push the commit to GitHub. Check on vercel for the new deployment. Vercel will automatically trigger a new deployment on every push. Incase it is not started, you can manually start a deployment.

  • Once new deployment is live, you can copy the deploy URL and run in browser. You will see Express Typescript on Vercel as a API response. Hurrah 😃

API working

  • To assure that API is working perfectly, you can also hit /ping route which will return pong 🏓 as the response.

Ping Pong response

Closing comments 🙋‍♂ī¸

  • Thank you for following steps with me. Incase you find any issue in above mentioned steps, please ping in comment.
  • Also a humble request you to write which topic you want in my next blog. I will include that in my target list. đŸŽ¯
  • Github repo link for this project : Express Typescript Code



Tirth Patel, signing off! đŸĢĄ

Top comments (36)

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aliffazmi profile image
Aliff Azmi • Edited

Thanks!

This is very helpful.

For those who's still stuck at 404 error code missing in Vercel. Just remove the ignore built ts files which is in your .gitignore file. In this case remove or comment out the dist directory.

Image description

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tirthpatel profile image
Tirth Patel

Good catch @aliffazmi. Thank you for pointing it out. 👍

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cel2022_01 profile image
Cel2022

It was useful but what I don´t undestand is why do we need to create dist directory?
That directory must be created when commit occurs but only into vercel.

  • Could you please explain that?
  • Have you tried to do the same but without the pre-commit dist folder creation?

How do I change the output directory in vercel.json #5081

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tirthpatel profile image
Tirth Patel

Hi @cel2022_01,
Good question. Actually the way VERCEL works is based on plain Javascript files. It can't directly operate on Typescript code. So inorder to run our Typescript based Express App, firstly we compile TS to JS. That compiled js source files are stored in dist folder. The path for dist folder is given in vercel config. So when any endpoint is hit to the server, VERCEL find the respective route in the dist folder and processes the request accordingly.

Hope this might resolve your query. Please continue the thread if more discussion is needed.
Thanks.

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thanhtutzaw profile image
ThanHtutZaw

We understand that but why can't vercel build and create the dist itself . Why dist need to be in git after git push .

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thanhtutzaw profile image
ThanHtutZaw

Deploying Nest and nextjs doesn't need to include dist folder in git source code .

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ristaa profile image
Milos Ristic • Edited

@thanhtutzaw @cel2022_01 @gaborpinter
I am a bit late to this, but:
The exact issue is that @vercel/node package, through builds prop in vercel.json, doesn't include buildCommand from vercel.json, it just serves what's already built.
However, builds and routes commands are deprecated and it's enough to use rewrite (vercel.com/docs/projects/project-c...).
The easiest solution would be to "skip" tsc and serve API directly through api/index.ts
vercel.json will look like:

{
  "rewrites": [
    {
      "source": "/(.*)",
      "destination": "/api"
    }
  ]
}
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gaborpinter profile image
GÃĄbor PintÊr

Any update on this question? Why indeed do we need to push compiled code to a "modern" platform?

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soozav profile image
Luis Verteliz • Edited

Hi Tirth, I'v tried to follow your instructions but I can make my app work, I get the following error: "Due to builds existing in your configuration file, the Build and Development Settings defined in your Project Settings will not apply."

In my app url I get the following error: "This Serverless Function has crashed".

Would you take a look at my code please?
github.com/SoozaV/sinecta-maps-bac...

Regards!

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soozav profile image
Luis Verteliz

I think I found out the issue looking at my function logs:

Image description

Do you have any idea on how to solve this? I can't find a solution.

Regards.

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tirthpatel profile image
Tirth Patel

Or you can do one more thing, in the vercel project setting page you can override the build command. You can try this one: npm i -g pg && npm run vercel-build

This will first install pg package in your VM on cloud server. Then you can access it while calling API. Please try this as well. And let me know if it works.

Cheers :)

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ashcript profile image
As Manjaka Josvah

I've tried it, but it seems like the error persists... Normally it should work, but I don't know why it doesn't... 😭

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ashcript profile image
As Manjaka Josvah

Image description

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ashcript profile image
As Manjaka Josvah

Finally, I've resolved it, not by installing pg globally with npm, but by adding the dialectModule option into my database configuration as below :

export const dbConfig = {
  username: process.env.DB_USERNAME,
  password: process.env.DB_PASSWORD,
  database: process.env.DB_NAME,
  host: process.env.DB_HOSTNAME,
  port: process.env.DB_PORT,
  dialect: 'postgres',
  dialectModule: pg, // I've added this.
  timezone: 'Etc/GMT+3', // Because process.env.TZ generated an error maybe due to time format
  define: {
    charset: 'utf8mb4',
    collate: 'utf8mb4_general_ci',
  },
  logging: false,
};
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scherpablo profile image
Pablo Scherpa

Hello, I have the same problem, I put the dialectModule: pg in the DB conifg and nothing, still with the error. I have the DB in supabase and in vercel I installed the integration with supabase to see if it would be corrected but it didn't either. I don't know what to do anymore, is there any other alternative? Thank you.

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tirthpatel profile image
Tirth Patel

Hi @soozav It seems there is some issue with pg package. I've found one resource that might help you. Please check this PG package issue

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fatemesoleymanian profile image
fatemesoleymanian

it helped me a lot! thank you

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mannu profile image
Mannu

Welcome to DEV community @fatemesoleymanian

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shimont profile image
Shimon Tolts

This tutorial helped me, thank you

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lucasvtiradentes profile image
Lucas Vieira

very useful thank you!

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pouriarezaeii profile image
Pouria Rezaei

Many thanks Tirth. I was stuck for 4 hours. Finally I found your post and Bingo!

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cakrads profile image
Cakra Danu Sedayu

thank you so much, this really helpful..

Is there a way to avoid pushing the dist folder?
So Vercel will build and generate the dist folder for us

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mihaiandrei97 profile image
Mihai-Adrian Andrei

Hello! Have you found a way?

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aezamorasanchez profile image
AEZamoraSanchez

hello i followed all the steps and uploaded my repository which is connected with sequelize to postgresql but i get this error:
Error: Please install pg package manually
at ConnectionManager._loadDialectModule (/var/task/node_modules/sequelize/lib/dialects/abstract/connection-manager.js:55:15)
at new ConnectionManager (/var/task/node_modules/sequelize/lib/dialects/postgres/connection-manager.js:15:24)
at new PostgresDialect (/var/task/node_modules/sequelize/lib/dialects/postgres/index.js:13:30)
at new Sequelize (/var/task/node_modules/sequelize/lib/sequelize.js:194:20)
at Object. (/var/task/dist/db-connection.js:8:14)
at Module._compile (node:internal/modules/cjs/loader:1358:14)
at Module._extensions..js (node:internal/modules/cjs/loader:1416:10)
at Module.load (node:internal/modules/cjs/loader:1208:32)
at Module._load (node:internal/modules/cjs/loader:1024:12)
at /opt/rust/nodejs.js:1:11506
anyone know how to fix it ?

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soydiego profile image
Diego Franchina

Hi, I hope you can help me.
I follow the tutorial and a lot of tutorials more and I couldn't get the solution.
Always I receive the same error on vercel: 404 not found.

I wrote a post in StackOverflow, maybe someone can reply or if you know what i'm doing wrong, i will appreaciate. This is the post of my question: stackoverflow.com/questions/775091...

Thanks for your time

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zhouzhonghao profile image
Bobby Zhou

Please refer to this question stackoverflow.com/questions/765767....
I posted an anwser there.

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zhouzhonghao profile image
Bobby Zhou

You need to share a demo so that another person can help you.

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soydiego profile image
Diego Franchina

Thanks. I didn't share a demo because I wrote my structure and my config file. with exactly all the things.