Create an Application

A small shop takes orders. Its application does not start from an empty file: one command writes an application that already runs, and the shop is built by changing it.

§What the machine needs

• Node.js 24 or later.
• Docker, for the broker, the database and Redis the application connects to.
• PM2, which keeps the application’s processes running:

$ npm install -g pm2

§Create it

$ mkdir store && cd store
$ npx -p @toa.io/cli -p @toa.io/userland toa create store

The directory has to be empty; .git may be there. store is the application’s name.

§Start it

$ npm install    # the packages
$ npm run dock   # the broker, the database and Redis, in Docker
$ npm run env    # what is generated from the sources: types, .env and .map.json
$ npm start      # the application

┌────┬────────┬─────────┬────────┬───────────┐
│ id │ name   │ mode    │ uptime │ status    │
├────┼────────┼─────────┼────────┼───────────┤
│ 1  │ app    │ fork    │ 3s     │ online    │
│ 0  │ sys    │ fork    │ 3s     │ online    │
└────┴────────┴─────────┴────────┴───────────┘

Two processes are running:

• app is the application: its components.
• sys is what Toa serves beside every application. The gateway, which answers HTTP on port 8000, is part of it.

They are separate here because they are separate in a deployment.

§Send a request

$ curl 'http://localhost:8000/hello/?name=Toa'

{"greeting":"Hello, Toa!"}

The application came with two components. hello answered this request; notes keeps notes:

$ curl http://localhost:8000/notes/ 
    -H 'content-type: application/json' 
    -d '{"text":"Buy milk"}'

{"id":"01a115eaddd7717ba992e9bc4d95b29c","text":"Buy milk"}

$ curl http://localhost:8000/notes/

[{"id":"01a115eaddd7717ba992e9bc4d95b29c","text":"Buy milk"}]

§Run its tests

$ npm run features

2 scenarios (2 passed)
8 steps (8 passed)

§Day to day

§What was created

Nothing here needs reading before the next article. Each file is explained where the shop first changes it: