# 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] -->|HTTPS plane=zapier| AZ[access-zapier]
  Web[customer browser] -->|HTTPS plane=web| AW[access-web]
  API[customer API] -->|HTTPS plane=api| AA[access-api]
  Leaf[S2S leaf] -->|verae.access.leaf.in| AL[access-leaf]
  AZ --> Authz[access-authz]
  AW --> Authz
  AA --> Authz
  AL --> Authz
  CS[staff CS/sales] --> Authz
  Authz -->|allow| N[NATS cluster]
  BAL[account-balance] --> N
  AZ -->|HTTPS| M[verae-middleware]
  M --> N
  N --> P[job-poller]
  N --> R[WORM]
  N --> T[tree-node]
  P --> C[Verae chain]
  M --> C
```

## 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).