• Head over to the "APIs" section in Xano.
• Click on "Add API Endpoint" to whip up a new endpoint.
• Define your endpoint by picking the method (GET, POST, etc.), and set up the route and any needed parameters.

• Go to the "Database" section in Xano.
• Create a new table, let's call it RateLimiter.
• Add fields to this table:
• ip_address (String): to store the requesting IP address.
• request_count (Integer): to store the number of requests made.
• timestamp (Timestamp): to store the time of the first request within the current rate limit window.

• Go to your shiny new API endpoint.

• Click on the "Before Script" section to add a new script.

• Add this logic to the script:

  ```js
  // Get client's IP address
  let ipAddress = request.headers['x-forwarded-for'] || request.connection.remoteAddress;

  // Set rate limit variables
  const MAX_REQUESTS = 100; // Maximum number of requests allowed
  const TIME_WINDOW = 60 _ 60 _ 1000; // Time window in milliseconds (1 hour)

  // Fetch entry from RateLimiter table
  let entry = await db.collection('RateLimiter').findOne({ip_address: ipAddress});

  // Check if entry exists
  if (entry) {
  let currentTime = new Date().getTime();

  // Check if the time window has expired
  if ((currentTime - entry.timestamp) < TIME_WINDOW) {
  // Check if the request count exceeds the limit
  if (entry.request_count >= MAX_REQUESTS) {
  throw new Error('Rate limit exceeded. Please try again later.');
  } else {
  // Increment the request count
  entry.request_count += 1;
  await db.collection('RateLimiter').updateOne({ip_address: ipAddress}, {$set: {request_count: entry.request_count}});
  }
  } else {
  // Reset the window and request count
  entry.timestamp = currentTime;
  entry.request_count = 1;
  await db.collection('RateLimiter').updateOne({ip_address: ipAddress}, {$set: {timestamp: entry.timestamp, request_count: entry.request_count}});
  }
  } else {
  // Create a new entry for the IP address
  await db.collection('RateLimiter').insertOne({ip_address: ipAddress, request_count: 1, timestamp: new Date().getTime()});
  }
  ```

• Use a tool like Postman or curl to send multiple requests to your API endpoint.
• Keep an eye on the response to make sure that requests going over the rate limit are blocked.

• Customize the error message and response when the rate limit is hit.

• You can tweak the script to return a specific status code and error message for better client-side handling.

  ```js
  // Custom error message
  if (entry.request_count >= MAX_REQUESTS) {
  response.status(429).json({error: 'Rate limit exceeded. Please try again later.'});
  return;
  }
  ```

Following these steps will set up a solid rate limiting mechanism for your API in Xano.