How do you read a JSON request body in Express.js?

Register the express.json() middleware so the parsed JSON payload is available on req.body.

With middleware (recommended):

app.use(express.json());
app.post('/api/users', (req, res) => {
  // Already parsed
  console.log(req.body);
});

Manual parsing:

const data = JSON.parse(req.body.toString('utf-8'));