Vibescript

Vibecoding will have a profound impact on personal computing. However, vibecoding still requires expertise. Generated code needs to be maintained, or it will rot and become vulnerable to attack. The future will consist of malleable software, where users vibecode their customizations on top of a base package.

Vibescript helps power this future with a small, statically typed scripting language for customizations on top of an existing app. The host decides which capabilities scripts can access and how much work they can do.

Vibescript’s Ruby-inspired syntax is easy to read. Its type checker catches mistakes before execution and offers fixes in its diagnostics, so people and AI can write custom behavior while the host app stays in control.

The language

Here’s a Vibescript function that totals a list of line items. Types are part of the function signature, and blocks make collection work straightforward.

def total(items: array<{ price: int, qty: int }>) -> int
  items.sum { |item| item["price"] * item["qty"] }
end

total([{ price: 250, qty: 2 }, { price: 100, qty: 1 }]) # 600

The language guide walks through the whole language with examples. Run vibes guide to print the bundled guide and vibes prelude to see the built-in functions and their signatures.

Try it

From a checkout, run the example or open the REPL.

./scripts/cargo run --release -p vibes -- examples/total.vibe --function total --arg '[10,20,30]'
./scripts/cargo run --release -p vibes -- repl

The CLI guide covers the commands for running, checking, formatting and testing scripts, plus editor setup.

Use it in a Rust app

Compile a script and call a function from your app.

use vibescript::{CallOptions, Engine, Value};

let mut engine = Engine::new();
let script = engine.compile("def run(n: int) -> int\n  n + 1\nend")?;
let result = script.call("run", &[Value::int(41)], CallOptions::default())?;

assert_eq!(result.value.as_int(), Some(42));

You can expose typed host functions and capabilities, then set the limits for each run. The embedding docs show how host code and scripts fit together.

Give an AI author vibescript::guide() for the language reference and engine.prelude(&options) for the built-in and configured host signatures.

A few more places to look

• Tested workflow examples
• AI authoring study
• Editor and language server setup
• WASI and platform support
• Runtime and VM design

The CLI, REPL, formatter, test runner and language server are all part of the project. The CLI guide has the details.

Validation

Run ./scripts/check for the local gate. GitHub Actions mirrors it on pull requests and pushes to master, using Rust 1.98.1: formatting and Clippy on Linux, debug, gate and doc tests on Linux x86_64 and macOS arm64, and the full golden corpora with both SIMD and portable builds on each host. Stable accounting counters must match between those builds; the goldens retain their documented tolerance for counter drift between platforms.

CI also runs python3 scripts/check-wasi on Linux with wasm32-wasip1 and Wasmtime 48.0.2. Dependencies are fetched with locked versions before offline checks, and the checkout-local Cargo and build directories are cached.

Fuzzing runs parser/compiler coverage targets in SIMD and portable builds and compares generated checker programs with the runtime. Pull requests run short checks; nightly campaigns retain corpora and upload failing inputs for reproduction.