Show HN: Triplit – Open-source syncing database that runs on server and client
Hey HN, we’re Matt and Will, the co-founders of Triplit (https://www.triplit.dev). Triplit is an open-source database (https://github.com/aspen-cloud/triplit) that combines a server-side database, client-side cache, and a sync engine into one cohesive product. You can try it out with a new project by running:

(npm|bun|yarn) create triplit-app

As a team, we’ve worked on several projects that aspired to the user experience of Linear or Superhuman, where every interaction feels instant like a native app while still having the collaborative and syncing features we expect from the web. Delivering this level of UX was incredibly challenging. In each app we built, we had to implement a local caching strategy, keep the cache up to date with optimistic writes, individually handle retries and rollbacks from failures, and do a lot of codegen to get Typescript to work properly. This was spread across multiple libraries and infrastructure providers and required constant maintenance.

We finally decided to build the system we always wanted. Triplit enables your app to work offline and sync in real-time over websockets with an enjoyable developer experience.

Triplit lets you (1) define your schema in Typescript and simply push to the server without writing migration files; (2) write queries that automatically update in real-time to both remote changes from the server and optimistic local mutations on the client—with complete Typescript types; (3) run the whole stack locally without having to run a bunch of Docker containers.

One interesting challenge of building a system like this is enabling partial replication and incremental query evaluation. In order to make loading times as fast as possible, Triplit will only fetch the minimal required data from the server to fulfill a specific query and then send granular updates to that client. This differs from other systems which either sync all of a user’s data (too slow for web apps) or repeatedly fetch the query to simulate a subscription (which bogs down your database and network bandwidth).

If you’re familiar with the complexity of cache-invalidation and syncing, you’ll know that Triplit is operating firmly in the distributed systems space. We did a lot of research and settled on a local first approach that uses a fairly simple CRDT (conflict-free replicated data type) that allows each client to work offline and guarantees that they will converge to a consistent state when syncing. It works by treating each attribute of an entity as a last writer wins register. Compared to more complex strategies, this approach ends up being faster and doesn’t require additional logic to handle conflicting edits between concurrent writers. It’s similar to the strategy Figma uses for their collaborative editor.

You can add Triplit to an existing project by installing the client NPM package. You may self-host the Triplit Server or pay us to manage an instance for you. One cool part is that whether you choose to self-host or deploy on Triplit Cloud, you can still use our Dashboard to configure your database or interactively manage your data in the Triplit Console, a spreadsheet-like GUI.

In the future, we plan to add APIs for authentication, file uploads, and presence to create a Supabase/Firebase-like experience.

You can get started by going to https://triplit.dev or find us on Github https://github.com/aspen-cloud/triplit. Thanks for checking us out and we are looking forward to your feedback in the comments!