diff --git a/docs/topology.md b/docs/topology.md
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+# Homelab Topology
+
+## Nodes
+
+| Node | Role |
+|---|---|
+| SATURN | Control and development node |
+| PIHA | Infrastructure and monitoring node |
+| SOLARIA | AI and compute node |
+| VPS | Public ingress and edge node |
+| CHELSTY | Virtualization and Home Assistant node |
+
+## Architecture Principles
+
+- Git is the source of truth.
+- SATURN is the primary orchestration and commit node.
+- Runtime state lives outside repositories.
+- Tailscale provides internal mesh networking.
+- Docker Compose remains the deployment model.
+- Public ingress is centralized on VPS.
+- Deployment uses lightweight shell scripts.
+- Avoid Kubernetes and heavy orchestration frameworks.
+
+## Runtime Layout
+
+Runtime data should live under:
+
+/opt/homelab
+
+with separated:
+- services
+- data
+- config
+- logs
diff --git a/hosts/chelsty/host.yaml b/hosts/chelsty/host.yaml
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+++ b/hosts/chelsty/host.yaml
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+hostname: chelsty
+
+roles:
+  - hypervisor
+  - homeassistant
+  - staging
+
+network:
+  tailscale_ip: 100.122.201.22
+
+runtime:
+  root: /opt/homelab
+
+deployment:
+  mode: pull
+  managed_by: saturn
diff --git a/inventory/topology.yaml b/inventory/topology.yaml
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+topology:
+  mesh: tailscale
+  git_provider: forgejo
+
+deployment:
+  mode: pull
+  orchestrator: saturn
+
+nodes:
+
+  saturn:
+    roles:
+      - control
+      - development
+
+  piha:
+    roles:
+      - infra
+      - monitoring
+
+  solaria:
+    roles:
+      - compute
+      - ai
+
+  vps:
+    roles:
+      - edge
+      - ingress
+
+  chelsty:
+    roles:
+      - hypervisor
+      - homeassistant
+      - staging