> ## Documentation Index
> Fetch the complete documentation index at: https://headgate.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Architecture
> How producer clients, stores, workers, APIs, and the console share one contract.
Headgate has a small driver-free core surrounded by replaceable adapters and consumers.
```mermaid theme={"system"}
flowchart TB
Spec[Proto + OpenAPI + conformance] --> Rust[Rust runtime]
Spec --> Go[Go runtime]
Rust --> Port[Store port]
Go --> Port
Port --> PG[(PostgreSQL)]
Port --> MY[(MySQL)]
Port --> RD[(Redis)]
API[Control API] --> Port
UI[Embedded console] --> API
```
## Responsibility boundaries
| Layer | Owns | Must not own |
| ------------- | ----------------------------------------------------------------- | ------------------------ |
| Core | Envelopes, outcomes, leases, state transitions, ports | Drivers, exporters, HTTP |
| Store adapter | Atomic admission, persistence, store clock, optional capabilities | Handler dispatch |
| Runtime | Typed dispatch, heartbeats, shutdown, panic isolation, steps | Fleet policy evaluation |
| Producer | Validation, authorization, middleware, hooks | Admission decisions |
| Control API | Bounded inspection and idempotent mutations | Queue-depth scans |
| Console | Operator experience | Direct database access |
Optional capabilities are explicit. A backend that cannot provide transactions,
inspection, or notifications declines that capability instead of exposing a no-op method.
## Shared truth
Rust and Go generate or derive from the same protocol, OpenAPI document, state machine,
and conformance scenarios. Neither implementation is used as the specification for the
other.