# System architecture

```mermaid
flowchart LR
  Input[User request] --> Core[Agent graph]
  Core --> Prompt[Versioned prompts]
  Core --> Tools[External tools]
  Core --> Memory[Memory / RAG]
  Core --> Output[Validated response]
  Evals[Offline evals] --> Gate[PR quality gate]
  Gate --> Core
```

The core must keep orchestration deterministic enough to test. Tools should have explicit schemas and timeouts. Memory adapters must make retention and deletion behavior visible.