# Architecture Overview

## Monorepo
- Rust workspace: aggregate, projection, runner, gateway, control/api, shared
- Frontend: control/ui
- Infra: docker, observability, swarm

## Data Flow
- Clients → Gateway (HTTP/JSON)
- Gateway ↔ Nodes (gRPC)
- Nodes ↔ NATS (JetStream + KV)

## Services
- Aggregate: command handling + event sourcing; publishes events to JetStream
- Projection: materialized views; consumes aggregate events; exposes QueryService (gRPC)
- Runner: workflow/saga engine + effects/outbox; exposes RunnerAdmin (gRPC)
- Gateway: edge, authn/z, routing to nodes, admin entry points

## Observability
- /health, /ready, /metrics on all services
- Correlation and tracing propagated across HTTP, gRPC, and NATS