get-convex/convex-backend

Convex is the backend-as-a-service for fullstack app development. Thoughtfully curated components, optimized by experts.

Convex replaces your database, server functions, scheduling, storage, vector search, etc. It includes a set of client libraries that deeply integrate with your frontend application code to provide fully consistent caching and real-time updates out of the box. All you need to do is write your application code.

The best way to get started with Convex is to follow the getting started guides in the Convex docs.

Most Convex developers should be using the managed hosted product. The hosted product includes a generous free tier and provides a seamless, reliable, cost-effective platform that allows you to focus on building your application without worrying about infrastructure.

This repository is the wild west open source version. It's the same code used in the hosted Convex product but runs on a single machine and doesn't include the scale-out services, replicated database backend, production dashboard, or operational tooling. You are welcome to use this code to run your application, either for local testing or in production, but you are on your own managing it and ensuring the system is reliable and secure. In particular you should ensure you have strong competency with regards to:

• Hosting
• Traffic routing
• Backups and replication
• Monitoring
• Upgrades
• Migration between versions

No official support is provided for the open source version of Convex but community support is available in the #open-source channel in the Convex Discord.

Development of the Convex backend is led by the Convex team and we are not actively soliciting any major contributions from the community. We of course welcome bug fixes and love receiving feedback. We keep this repository synced with any internal development work within a handful of days.

We strongly recommend using the hosted version of Convex to get familiar with the development workflow before attempting to run this version locally.

To get started, clone this repo:

git clone https://github.com/get-convex/convex-backend.git
cd convex-backend

You will need to first install the following dependencies if you don't already have them on your machine:

To use the scripts set up in this repo:

• Just
  • Just is used to execute scripts set up in the Justfile.
  • To install it see Packages, for example cargo install just or brew install just

To run the Convex CLI:

• Node.js
  • Make sure you have the version specified in .nvmrc
  • We recommend installing Node.js via nvm.
  • Run nvm use from the root of the repo.

To build the backend from source:

• Cargo
  • The convex local backend is written in Rust. Cargo is the build system.
  • We recommend installing Cargo via rustup.
• The Rust nightly version specified in rust-toolchain
  • Assuming you installed Rust/Cargo with rustup, this will install automatically.
• Rush
  • npm install --prefix scripts
  • We manage the packages in a monorepo using Rush.
• Convex JavaScript dependencies
  • just rush install

You can download the latest precompiled binary release from Releases. Only Apple x64, Apple Arm64 (Apple silicon), and Linux x64 binaries are currently available for download.

Note: On MacOS you might need to hold the option key and double click the binary file in Finder once, to circumvent the Gatekeeper warning.

Then you can run it:

./convex-local-backend

Adjust the path based on where you downloaded the binary to or add it to your PATH. The backend will store its database in the directory where it is executed from (not where the binary file lives).

Build and run the local backend from the source in this repo:

just run-local-backend

Under the hood, this builds with Cargo:

cargo run -p local_backend --bin convex-local-backend

This example will go through running the backend with the included demo project.

1. Start the backend

Run the backend

If this fails with an error "persisted db metadata ..." you might need to erase the local database, in root directory run rm convex_local_backend.sqlite3.

2. Develop against the backend

The Convex CLI watches for changes in the application source code and pushes the code to backend.

To make the local backend run the included demo project, do:

cd demo
npm i
just convex dev

The convex script in Justfile automatically adds appropriate --url and --admin-key flags to point the CLI to the local backend.

To run the client web application you can run the demo Vite server via:

npm run dev:client

Note that unlike the hosted Convex workflow, we don't want to run the dev:server command since convex dev is already running.

The following CLI commands may be useful when interacting with your backend:

• just convex data - Lists tables in your Convex deployment
• just convex env - Allows you to list/set/update/delete environment variables
• just convex logs - Streams out log lines to the terminal (it includes all successful executions if --success is passed in)
• just convex import - Allows you to import tables
• just convex export - Allows you to export tables

For full documentation visit docs.convex.dev.

To see how to contribute, visit Contributing.md.

• Discord. Best for: sharing your applications, hanging out with the community, and help with building on Convex
• GitHub Issues. Best for: surfacing bugs and errors you encounter while building and using the open source Convex backend

• The Convex local backend is designed for use in local development and testing. Please exercise caution if attempting to use it for production usage. Convex can't offer support or guarantees for that experience - you're on your own there. If you do choose to go down that route, make sure to change your admin key from the defaults in the repo.
• The Convex local backend doesn't have backward compatibility guarantees for CLI compatibility. Once a feature is released in a CLI, the backend will support it from that point on, but newer CLI features may not work with older backends. Unreleased/beta features won't have any guarantees.
• Convex local backend does not support robust backend migrations. We'll always ensure things will work if you wipe your local database and start from scratch. We do not provide support for upgrading an existing local-backend to a newer version.
• If you're using both the local backend and the hosted cloud platform, make sure to run npx convex dev or just convex dev before you start testing your client. The dev command will take care of updating your .env.local file with the correct CONVEX_URL.

• crates/ contains Rust code

  • Main binary
    • local_backend/ is an application server on top of the Runtime. This is the serving edge for the Convex cloud.

• npm-packages/ contains both our public and internal TypeScript packages.

  • Internal packages
    • udf-runtime/ sets up the user-defined functions JS environment for queries and mutations
    • udf-tests/ is a collection of functions used in testing the isolate layer
    • system-udfs/ contains functions used by the Convex system e.g. the CLI

• demo/ contains a demo project that showcases the basic functionality of Convex using React