venus

Not supported yet

• Async cells. A cell is a synchronous function, so block on a future inside the cell.
• Sandboxing. See Security.

Security

Venus executes arbitrary Rust code with full system access. It provides no sandboxing. Cells can read and write files, open network connections, and spawn processes.

• Use Venus for local development, testing, and learning.
• Do not run Venus on production servers, shared servers, or with untrusted code.
• Cloud providers must isolate Venus in containers or virtual machines.

You are responsible for running Venus in a secure environment. See SECURITY.md for details.

Quick Start

Install the venus and venus-worker binaries:

cargo install venus

Create a notebook, run it, and start the web server:

venus new hello
venus run hello.rs
venus serve hello.rs

venus new adds the notebook as a binary to Cargo.toml. This enables rust-analyzer support. Open http://localhost:8080 in your browser to use the web UI.

Example

use venus::prelude::*;

#[derive(Debug, Clone)]
pub struct Config {
    pub count: i32,
}

/// Analysis config
#[venus::cell]
pub fn config() -> Config {
    Config { count: 10 }
}

/// Generate squared numbers
#[venus::cell]
pub fn numbers(config: &Config) -> Vec<i32> {
    (1..=config.count).map(|i| i * i).collect()
}

/// Calculate the sum
#[venus::cell]
pub fn total(numbers: &Vec<i32>) -> i32 {
    numbers.iter().sum()
}

Cells

• A cell is a function marked with #[venus::cell].
• A parameter name refers to the cell with that name. In the example, numbers reads the config cell.
• The return type is the cell output that other cells read.
• Each /// doc comment becomes the cell description in the UI.

Features

• Web UI: Monaco editor, cell outputs, and execution status.
• Native Rust files: notebooks are .rs files with full rust-analyzer support.
• Reactive dependencies: Venus marks dependent cells dirty when an upstream cell changes.
• Hot reload: modified cells re-run and keep state from the other cells.
• Widgets: input_slider, input_text, input_select, and input_checkbox build interactive inputs.
• Rich output: the Render trait produces text, HTML, image, and JSON output. The polars feature renders DataFrames. The image feature renders PNG output.
• Markdown cells: notes between code cells in the web UI.
• Jupyter export: venus sync writes an .ipynb file for GitHub preview.
• Optional Cranelift: the Cranelift backend speeds debug builds of cells. Without it, Venus uses the LLVM backend.

See docs/widgets.md and docs/render.md for details.

Optional: Cranelift backend

Install the Cranelift component on nightly:

rustup toolchain install nightly
rustup component add rustc-codegen-cranelift-preview --toolchain nightly

Venus detects the component and uses it when available. No config is needed.

CLI Commands

Pass -v or --verbose with any subcommand for verbose logging. The --release flag uses the LLVM backend with optimizations. venus new --workspace creates the notebook as a workspace member in a separate directory.

Documentation

• Installation: platform setup and the optional Cranelift backend
• Getting Started: create your first notebook
• How It Works: execution model and architecture
• Cells: cell syntax and dependencies
• Widgets: interactive inputs
• Render Trait: custom output formatting
• CLI Reference: command-line flags
• API Reference: build custom frontends
• Deployment: deployment guidance
• FAQ and Troubleshooting
• API Stability: versioning and breaking change policy

Contributing

Contributions are welcome. See CONTRIBUTING.md for conventions and checks.

Questions and design discussion happen on Discord.

License

Licensed under Apache-2.0. See LICENSE.