apiAuth.js

const users = [

    {
        _id: 0,
        api_key: "YOUR_API_KEY",
        username: "YOUR_USERNAME",
        usage: [{}],
      },

];

const MAX = 99999999999;

const authenticateKey = (req, res, next) => {
    let api_key = req.header("x-api-key"); //Add API key to headers
    let account = users.find((user) => user.api_key == api_key);
    // find() returns an object or undefined
    if (account) {
      //If API key matches
      //check the number of times the API has been used in a particular day
      let today = new Date().toISOString().split("T")[0];
      let usageCount = account.usage.findIndex((day) => day.date == today);
      if (usageCount >= 0) {
        //If API is already used today
        if (account.usage[usageCount].count >= MAX) {
          //stop if the usage exceeds max API calls
          res.status(429).send({
            error: {
              code: 429,
              message: "Max API calls exceeded.",
            },
          });
        } else {
          //have not hit todays max usage
          account.usage[usageCount].count++;
          console.log("Good API call", account.usage[usageCount]);
          next();
        }
      } else {
        //Push todays's date and count: 1 if there is a past date
        account.usage.push({ date: today, count: 1 });
        //ok to use again
        next();
      }
    } else {
      //Reject request if API key doesn't match
      res.status(403).send({ error: { code: 403, message: "Access Denied." } });
    }
  };
  module.exports = { authenticateKey };