Convex

Building a web app normally means gluing a database to an API layer to a client cache. Convex removes those seams, an open source reactive database aimed at web app developers and explicitly at the LLMs writing code beside them, where data fetching and business logic are written as pure TypeScript with strong consistency.

The product is three things at once. A database, a place to write server functions, and client libraries that keep the front end current as the underlying data changes, which is what makes live-updating apps straightforward to build and scale.

A few things are worth knowing before committing to the open source build.

• Repository layout: Rust crates hold the backend, with local_backend acting as the application server, while TypeScript packages carry the public and internal SDKs.
• Test suites: the team's well designed test frameworks, randomized testing included, are not part of the open source offering.
• Platform maturity: Linux and macOS are the most thoroughly tested, Windows much less so.
• Telemetry: self-hosted builds send an anonymous beacon carrying a random deployment id, migration version, git revision and uptime, which a flag disables.

Self-hosting includes most of the cloud product, dashboard and CLI included, running through Docker or a prebuilt binary and working with Postgres, SQLite and hosts such as Neon, Fly.io, Vercel and Netlify. If you build from source rather than following the guide, change the instance secret and admin key away from the repository defaults before exposing anything.