Convex is an open-source reactive database designed for Web application developers (including humans and LLMs), aiming to simplify development work. It writes data fetching and business logic in pure TypeScript and guarantees strong consistency. Convex provides a database, a place to write server functions, and client libraries, helping developers easily build and scale dynamic real-time updating applications.
Main capabilities:
- Reactive database: Data changes are automatically updated to clients in real time.
- Business logic written in pure TypeScript: Queries and mutations use user-defined functions (UDFs).
- Strong consistency: Data operations are guaranteed to be consistent.
- Cloud platform: Provides a generous free tier, suitable for running small applications and side projects at zero cost.
- Self-hosting: Includes most cloud features such as a dashboard and CLI, and can work with tools such as Neon, Fly.io, Vercel, Netlify, RDS, Sqlite, and Postgres.
- Deployment methods: Docker is recommended, and precompiled binaries can also be used.
Usage:
- Getting started: Visit the official documentation for guides.
- Cloud: Use the Convex cloud platform to build quickly.
- Self-hosting: Refer to the self-hosting guide; Docker or precompiled binaries can be used. Community support is available in the #self-hosted channel on Discord.
- Building from source: Not recommended; if you choose this, refer to the self-hosting guide, and be sure to change the instance secret and admin key.
- Self-hosted builds include a beacon to help improve the product. The information is anonymous and minimal, and can be disabled with the --disable-beacon flag. Beacon messages include: a random identifier for the deployment (not used elsewhere), the database migration version, the backend Git version, and the backend runtime.
Applicable scenarios:
- Web applications that require real-time data updates.
- Projects that want to unify frontend and backend logic with TypeScript.
- Small applications and side projects can run with zero maintenance using the free tier.
- Scenarios that require self-hosting or integration with existing toolsets.
Limitations:
- The open-source version does not include the internal testing framework.
- It is most thoroughly tested on Linux and Mac, with less experience on Windows.
- When self-hosting, be careful to change the default instance secret and admin key.
- The beacon can be disabled, but it is enabled by default.
Repository layout:
- crates/: Rust code. The main binary local_backend/ is the runtime's application server, serving as the serving edge of Convex Cloud.
- npm-packages/: Public and internal TypeScript packages. Among the internal packages, udf-runtime/ sets up the JS environment for user-defined functions; system-udfs/ contains functions used by Convex systems (such as the CLI).
Community and support: Help is available through Discord, and issues can be reported through GitHub Issues. Submitting a PR indicates confirmation that Convex may use, modify, copy, and redistribute the contribution under the terms it chooses.
