ranvier

Ranvier is a Typed Decision Engine for Rust. This crate is the facade entry point that re-exports the core, runtime, and HTTP ingress layers.

Install

cargo add ranvier

Quick Start

use async_trait::async_trait;
use ranvier::prelude::*;

#[derive(Clone)]
struct Hello;

#[async_trait]
impl Transition<(), String> for Hello {
    type Error = anyhow::Error;
    type Resources = ();

    async fn run(
        &self,
        _state: (),
        _resources: &Self::Resources,
        _bus: &mut Bus,
    ) -> Outcome<String, Self::Error> {
        Outcome::Next("Hello, Ranvier!".to_string())
    }
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let hello = Axon::<(), (), anyhow::Error>::new("Hello").then(Hello);

    Ranvier::http()
        .bind("127.0.0.1:3000")
        .route("/", hello)
        .run(())
        .await
        .map_err(|e| anyhow::anyhow!("{}", e))?;

    Ok(())
}

Notes

• Ranvier::http() is an Ingress Builder, not a web server.
• Core contracts stay protocol-agnostic. HTTP semantics live in the adapter layer.

Features

Default features include the HTTP ingress adapter and std nodes. To slim down dependencies:

ranvier = { version = "0.21.0", default-features = false }

You can enable features explicitly:

ranvier = { version = "0.21.0", features = ["http", "std"] }

Crates (10-crate architecture, v0.21.0)

13 wrapper crates were removed in v0.21.0. Use external libraries directly with Transition-pattern examples.

Examples

• hello-world — HTTP ingress baseline (uses ranvier facade crate)

MSRV

• Rust 1.93.0 or newer (Edition 2024).