> ## Documentation Index
> Fetch the complete documentation index at: https://docs-unity.molca.id/llms.txt
> Use this file to discover all available pages before exploring further.

# DT SDK architecture

> How the Digital Twin SDK layers on Unity and Molca Core, and key domain terms.

**Product:** [Digital Twin SDK](/dt/overview) — `Assets/_MolcaDT/`. For **shared Core** concepts (runtime, settings, HTTP patterns), see [Architecture](/overview/architecture) and [Molca Core](/core/runtime-manager).

## Layers

```mermaid theme={null}
flowchart TB
  subgraph app["Twin application"]
    Scenes["Scenes · twin UI · machine views"]
  end
  subgraph molcaDT["Molca DT — Assets/_MolcaDT"]
    Mgrs["Managers — preload, login, menu, loading, search, factory, shell …"]
    Net["Network — API mappers, tokens, SSE-style clients"]
    POI["POI & handlers — points of interest, panels, machine UI"]
  end
  subgraph core["Molca Core (when wired)"]
    C["RuntimeManager · HTTP · events · settings modules"]
  end
  subgraph unity["Unity"]
    U["Desktop / URP / UI Toolkit or uGUI"]
  end
  Scenes --> Mgrs
  Mgrs --> Net
  Mgrs --> POI
  Net --> core
  POI --> core
  core --> U
```

Templates vary: some DT projects lean heavily on Core; others isolate twin code. Confirm your repo’s **MolcaProjectSettings** and **GlobalSettings** ([Runtime and settings](/overview/runtime-and-settings)).

## Domain glossary (DT)

| Term              | Typical role                                                                                                   |
| ----------------- | -------------------------------------------------------------------------------------------------------------- |
| **POI**           | Point of interest — follow targets, selection, `POIManager` / handlers ([POI and panels](/dt/poi-and-panels)). |
| panels / handlers | Machine or asset **overview**, **data**, **working order** UIs — see `_MolcaDT` handler scripts.               |
| **Network**       | HTTP clients, token renewal, JSON mapping ([Network and mapping](/dt/network-and-mapping)).                    |
| **Startup flow**  | Preload → login → main menu → load twin context ([Startup flow](/dt/startup-flow)).                            |

VR-specific terms (**scenario**, **ScenarioManager**, **Step** training tree) do **not** apply to standard DT flows — see [VR SDK overview](/vr/sdk-overview) only if you also embed VR.

## Related

* [DT overview](/dt/overview) — what ships in `_MolcaDT`
* [DT project layout](/dt/project-layout) — folder map
* [Platforms](/overview/platforms) — DT vs VR repos
* [VR architecture](/vr/architecture) — contrast: training/XR stack