Add a New Express Project
Supported Features
Because we are using an Nx plugin for Express, all the features of Nx are available.
✅ Run Tasks ✅ Cache Task Results ✅ Share Your Cache ✅ Explore the Graph ✅ Distribute Task Execution ✅ Integrate with Editors ✅ Automate Updating Nx ✅ Enforce Module Boundaries ✅ Use Code Generators ✅ Automate Updating Framework Dependencies
Install the Express Plugin
Make sure to install the @nx/express version that matches the version of nx in your repository. If the version numbers get out of sync, you can encounter some difficult to debug errors. You can fix Nx version mismatches with this recipe.
❯
nx add @nx/express
Create an Application
Use the app generator to create a new Express app.
The command below uses the as-provided directory flag behavior, which is the default in Nx 16.8.0. If you're on an earlier version of Nx or using the derived option, omit the --directory flag. See the as-provided vs. derived documentation for more details.
❯
nx g @nx/express:app my-express-api --directory=apps/my-express-api
Serve the API by running
❯
nx serve my-express-api
This starts the application on localhost:3333/api by default.
Create a Library
The @nx/express plugin does not have a library generator, but we can use the library generator from the @nx/js plugin. To create a new library, install the @nx/js package and run:
The command below uses the as-provided directory flag behavior, which is the default in Nx 16.8.0. If you're on an earlier version of Nx or using the derived option, omit the --directory flag. See the as-provided vs. derived documentation for more details.
❯
nx g @nx/js:lib my-lib --directory=libs/my-lib
Once the library is created, update the following files.
1export function someFunction(): string {
2 return 'some function';
3}
41/**
2 * This is not a production server yet!
3 * This is only a minimal backend to get started.
4 */
5
6import express from 'express';
7import * as path from 'path';
8import { someFunction } from '@my-express-app/my-lib';
9
10const app = express();
11
12app.use('/assets', express.static(path.join(__dirname, 'assets')));
13
14app.get('/api', (req, res) => {
15 res.send({ message: `Welcome to my-express-app! ${someFunction()}` });
16});
17
18const port = process.env.PORT || 3333;
19const server = app.listen(port, () => {
20 console.log(`Listening at http://localhost:${port}/api`);
21});
22server.on('error', console.error);
23Now when you serve your API, you'll see the content from the library being displayed.