# 8. Architectural diagrams

SVG files in [`diagrams/`](diagrams/). The same shapes are repeated below in mermaid for Forgejo preview.

## 8.1 End-to-end (HTTPS vs NATS)

![System](diagrams/system.svg)

```mermaid
flowchart LR
  Z[Zapier cloud apps] -->|HTTPS x-api-key| E[zappier-edge]
  CS[customer-service] --> E
  SA[sales-pricing] --> E
  AC[accounting-export QuickBooks] --> E
  E -->|HTTPS metered| M[verae-middleware]
  M -->|HTTPS| C[Verae chain]
  M -->|JetStream| N[NATS 3-node cluster]
  N --> P[job-poller]
  N --> W[webhook-deliver]
  N --> A[archive-aggregator]
  N --> R[WORM x N]
  N --> T[tree-node x N]
  P -->|HTTPS status| C
  W -->|HTTPS REST Hook| Z
```

## 8.2 NATS.IO 3-server cluster

![Cluster](diagrams/nats-cluster.svg)

```mermaid
flowchart TB
  subgraph cluster [Verae NATS.IO JetStream]
    N1[nats-server A :4222 loopback]
    N2[nats-server B]
    N3[nats-server C]
    N1 <--> N2
    N2 <--> N3
    N3 <--> N1
  end
  MW[middleware + workers] -->|cluster URL list| cluster
  F[fleet SSH hosts] -->|workers only| cluster
```

## 8.3 Uptime and failure

![Uptime](diagrams/uptime.svg)

```mermaid
flowchart TD
  H[health /health] -->|fail| R[restart instance]
  P[pause] -->|not available| F[keepFloor spawn]
  S[SSH host down] -->|spawn failed| O[place on next machine]
  Q[archive.query broadcast] -->|bloom miss| SIL[silence]
  Q -->|hit| REP[archive.reply.id]
```

## 8.4 New address = new process

![Routing](diagrams/routing.svg)

See [09-expansion-template.md](09-expansion-template.md).