JSON APIs

In-memory collection

A beginner-friendly pattern: keep data in an array while learning routing.

const notes = [
  { id: 1, text: "Learn Express" },
];

app.get("/notes", (req, res) => {
  res.json(notes);
});

Create with POST

Require JSON middleware, then push a new item.

app.post("/notes", (req, res) => {
  const text = req.body?.text;
  if (!text) {
    return res.status(400).json({ error: "text is required" });
  }
  const note = { id: Date.now(), text };
  notes.push(note);
  res.status(201).json(note);
});

Try with curl

From another terminal while the server runs:

curl http://localhost:3000/notes
curl -X POST http://localhost:3000/notes \
  -H "Content-Type: application/json" \
  -d '{"text":"Ship it"}'

Later: a real database

Replace the array with SQLite, Postgres, or another store once routes feel comfortable.