diff --git a/src/Ratelimit.js b/src/Ratelimit.js
new file mode 100644
index 0000000..f43157d
--- /dev/null
+++ b/src/Ratelimit.js
@@ -0,0 +1,40 @@
+
+var RateLimit = function(interval_ms) {
+	this._interval_ms = interval_ms || 0; // (0 means no limit)
+	this._after = 0;
+};
+
+RateLimit.prototype.attempt = function(time) {
+	var time = time || Date.now();
+	if(time < this._after) return false;
+	this._after = time + this._interval_ms;
+	return true;
+};
+
+RateLimit.prototype.setInterval = function(interval_ms) {
+	this._after += interval_ms - this._interval_ms;
+	this._interval_ms = interval_ms;
+};
+
+var RateLimitChain = function(num, interval_ms) {
+	this.setNumAndInterval(num, interval_ms);
+};
+
+RateLimitChain.prototype.attempt = function(time) {
+	var time = time || Date.now();
+	for(var i = 0; i < this._chain.length; i++) {
+		if(this._chain[i].attempt(time)) return true;
+	}
+	return false;
+};
+
+RateLimitChain.prototype.setNumAndInterval = function(num, interval_ms) {
+	this._chain = [];
+	for(var i = 0; i < num; i++) {
+		this._chain.push(new RateLimit(interval_ms));
+	}
+};
+
+var exports = typeof module !== "undefined" ? module.exports : this;
+exports.RateLimit = RateLimit;
+exports.RateLimitChain = RateLimitChain;