Passing parameters to an API

api.js

app.get('/api/todo/:key', (req, res, next) => {
  todos.findOne({ key: req.params.key })
    .then(result => {
      if (!result) {
        return next({ status: 404, message: 'not found' });
      }
      res.status(200).json(result);
    })
    .catch(err => {
      return next({ status: 500, message: err.message });
    });
});