October 30, 2023 - 3 Min Read

Momento just got more powerful: Introducing Topics

Build more secure and efficient pub/sub systems with token identifiers in Momento Topics.

Pratik Agarwal
Allen Helton


We started Momento with a simple vision to make the lives of developers easier. Every hour developers spend configuring servers and dealing with inevitable machine failures has an opportunity cost against innovation. Automating common tasks and best practices to deliver out-of-the-box availability, security, and performance helps us inject efficiency into the ecosystem. This delightful developer experience leads to increased velocity for our customers. We have made meaningful progress here with caching—but we are just getting started. 

a GIF showing a squirrel leaping off screen once a countdown reaches 0

Today, we are announcing Momento Topics, the fastest and easiest messaging pipeline for building event-driven architectures. Today, you can publish to a channel with thousands of subscribers without any configurations. In fact, you can do this from scratch in less time than it takes you to read this blog or launch a traditional messaging cluster. What if your service got popular and you suddenly have to process millions of messages per second? The last thing you want to do in that scenario is benchmark nodes, shard the cluster, and rejigger things to sustain the load. 

Topics follows the Momento pricing tenets: usage-based and simple enough to fit in a tweet. Best of all, Momento free tier applies! Your first 50 GB of Momento traffic is on us. 

Simple usage-based-pricing for a scalable messaging system that you can put to production today is already a great deal—but it gets better! We have built a solid foundation and have a vision for what Topics will do for our customers. One of the biggest problems with many existing pub/sub implementations is that any messages that get sent while a subscriber isn’t listening get dropped on the floor. Our messages have sequence numbers built in, allowing you to detect if they missed a message. In the near future, Topics will allow you to start the Topics subscription with a sequence number as a checkpoint. 

Topics is a fundamental building block that we will extend to delight developers further. We are particularly excited about two upcoming features we will build on top of Topics.

  1. Momento executors will let you attach a Lambda function in your AWS account to a topic. Momento will automatically execute these functions for you without you having to subscribe to a topic.
  2. Momento triggers will let you subscribe to changes on specific item(s) in your cache. It gets better. You’ll be able to set up rules that only notify you when a specific condition is met, like a counter hitting 1000 or key expiring. Best of all, executors and triggers will work together.

Said differently, executors will let you avoid subscribing and triggers will help you avoid publishing. That’s right: the Momento bar for simplicity in a pub/sub system is to completely obviate publishing and subscribing. The world is indeed asynchronous! 

Topics is the first fully serverless messaging system that scales to millions of messages per second, has single-digit milliseconds for tail latencies, and just works out of the box. Instead of provisioning caching clusters, benchmarking them, sizing them, and then managing the distribution of pub/sub topics across shards, you can just use Momento Topics and get your idea to prod today.

Check out the Topics documentation for a deeper dive—then try it free and let us know what you think!