> For the complete documentation index, see [llms.txt](https://docs.unitlab.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.unitlab.ai/api-sdk-cli/sdks/data-units.md).

# Data Units

{% hint style="info" %}
**Outcome:** List and retrieve loose datasource or grouped project work units with stable filters.
{% endhint %}

```python
units = project.data_units(
    search="study-001",
    data_type="medical",
    status="annotate",
    kind="group",
)

unit = client.get_data_unit(project.id, units[0].id)
print(unit.kind, unit.items)
```

A loose file is a `datasource` Data Unit. A Data Group is a `group` Data Unit whose `items` contain member tile summaries; members are not duplicated in the top-level list. Available filters are `search`, `data_type`, `status`, `batch_queue`, and `kind`.

Use Data Unit IDs for task-scoped automation and retain group membership when downstream work depends on context.

### Operating contract

| Concern           | Required behavior                                                                |
| ----------------- | -------------------------------------------------------------------------------- |
| Execution surface | Pinned `unitlab==3.0.0` application environment on Python 3.10+.                 |
| Identity          | Least-privilege API key supplied through approved configuration.                 |
| Target resolution | Stable resource IDs and an explicitly bounded target set.                        |
| Success evidence  | Typed return fields, server-side state, and downstream acceptance of the result. |

### Failure and recovery boundary

| Condition                                       | Response                                                                                                     |
| ----------------------------------------------- | ------------------------------------------------------------------------------------------------------------ |
| Authentication or authorization fails           | Stop, correct the service identity or access model, rotate exposed credentials, and rerun a read-only check. |
| Validation or entitlement rejects the operation | Correct the input or entitlement; do not retry an unchanged request.                                         |
| A request times out                             | Inspect remote state before repeating a mutation because the server may have accepted it.                    |
| Asynchronous processing exceeds its deadline    | Preserve the Batch Queue or release ID, continue bounded monitoring, and inspect item-level failures.        |
| Only part of a batch succeeds                   | Keep successful identifiers, isolate failed rows, and retry only the corrected subset.                       |

{% hint style="warning" %}
Pin and test the production SDK version. Use stable IDs, keep secrets out of logs and command history, and record the correlation ID, target IDs, counts, final state, and redacted error details for material state changes.
{% endhint %}