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

# Machine Data Artifact

> Persistence backend for placed machine instances.

The `machine_data_artifact` entry stores every placed machine instance — position, owner, inventory, energy charge and processing progress — as JSON. Point each [machine\_definition](../definition/machine_definition.mdx)'s `storageRef` at one.

| Field        | Default        | Description                                                                                |
| :----------- | :------------- | :----------------------------------------------------------------------------------------- |
| `artifactId` | `machine-data` | Unique artifact identifier. **Do not change after creation** or stored instances are lost. |

Instances are saved on shutdown and restored after the definitions are published at startup, so machines resume exactly where they stopped.