# car-engine

Core runtime engine for the [Common Agent Runtime](https://github.com/Parslee-ai/car).

## What it does

The engine receives action proposals from a model, builds a dependency DAG, and executes actions
concurrently where possible. It handles validation, idempotency, timeouts, retries, and state
rollback on abort. Integrates with `car-policy` for rule enforcement and `car-eventlog` for
audit logging.

## Usage

```rust
use car_engine::{Runtime, ToolExecutor, CostBudget};
use car_ir::ActionProposal;

// Register tools and execute proposals
let runtime = Runtime::new(state, policy, eventlog, tools);
let result = runtime.execute(&proposal).await?;
```

## Crate features

- DAG-based concurrent execution
- Result caching with `ResultCache`
- Rate limiting with `RateLimiter`
- Capability-based tool access control
- Checkpoint/restore for crash recovery

Part of [CAR](https://github.com/Parslee-ai/car) -- see the main repo for full documentation.
