Skip to content


A program runtime is an operating system and software stack that enables your program to run on the network.

Runtimes are customized Linux root filesystems that integrate with the infrastructure and provide access to APIs, as well as quick responses to HTTP requests and other events.

The project provides official runtimes with all you need for most programs. Additionally, you can build and publish custom runtimes, and use any available runtime on the network for your program.

Existing Runtimes

Official runtime with Debian 11, Python 3.9 and NodeJS 14 provides users with a default runtime based on Debian 11 "bullseye", the current stable version of the Debian project which can be found on the Explorer. This runtime is built with software available in the distribution, including Python 3.9 and Nodejs 14.

To optimize performance, this runtime uses a custom Linux init process. This process is specially designed to quickly launch the right endpoint in response to events such as HTTP requests. This is especially useful when using on-demand execution.

Third-party runtimes

Use third-party runtimes available on the network by specifying their item_hash when creating your program.

Init process

On-demand Execution relies on a custom Linux init process, optimized to launch the right endpoint in response to events such as HTTP requests. This custom init consists in two simple programs, and

Use these in your custom runtime by copying them to /rootfs/sbin/init and /mnt/rootfs/root/ respectively.

Persistent Execution may use the same init process, but this is not required. If you do not make use of the capabilities provided by the ecosystem, using the default of your distribution (ex: systemd, OpenRC, ...) should work as well.

List of official runtimes


name runtime filesystem
Debian 11 “Bullseye” 887957042bb0e360da3485ed33175882ce72a70d79f1ba599400ff4802b7cee7 BTRFS
Debian 12 “Bookworm” 6e30de68c6cedfa6b45240c2b51e52495ac6fb1bd4b36457b3d5ca307594d595 BTRFS
Ubuntu 22.04 LTS 77fef271aa6ff9825efa3186ca2e715d19e7108279b817201c69c34cedc74c27 BTRFS


name runtime filesystem
Official runtime with Debian 11, Python 3.9 & Node.js 14 bd79839bf96e595a06da5ac0b6ba51dea6f7e2591bb913deccded04d831d29f4 ext4
Official runtime with Debian 12, Python 3.11 63f07193e6ee9d207b7d1fcf8286f9aee34e6f12f101d2ec77c1229f92964696 ext4
Official Node.js LTS runtime (with nvm support) on Debian 11 3c238dd3ffba73ab9b2cccb90a11e40e78aff396152de922a6d794a0a65a305e ext4