# Ranvier Runtime (`ranvier-runtime`)
> **The Engine:** Async execution and state management for Ranvier circuits.
## 🎯 Purpose
`ranvier-runtime` provides the practical implementation for executing `Axon` circuits defined in `ranvier-core`. It handles:
- **Async Traversal**: Walking through the state tree asynchronously.
- **Bus Management**: Safely carrying the type-map state through transitions.
- **Tracing Integration**: Providing detailed execution logs and spans for debugging.
## 🔑 Key Components
- **`Axon` (Implementation)**: Concrete structures for building and nesting circuits.
- **`Bus` (Implementation)**: The thread-safe container for circuit state.
- **`Outcome` Handling**: Logic to resolve branches, loops, and faults during execution.
## 🚀 Usage
```rust
use ranvier_runtime::Axon;
use ranvier_core::prelude::*;
// Runtime is where the Axon builder and execution logic lives
let axon = Axon::start("MyCircuit")
.then(some_transition);
```
## MSRV
- Rust `1.85.0` or newer.