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

# Data classes

> Choose how sensitive a room's content is, and know what that choice controls.

Every room has a data class, from C0 to C3. It states how sensitive the room's content is. Ainomos uses it to decide which AI models may read that content and how personal data in it is handled. The data class is set when the room is created and cannot be changed later, so choose it with care.

## The four classes

| Class | Label in the app | Meant for |
| - | - | - |
| C0 | experimental | Trials without protected data. Models used for C0 may process data outside the EU and Switzerland. |
| C1 | internal | General internal content with a low protection need. The first setup creates its department rooms as C1. |
| C2 | confidential | Sensitive content for a restricted group, including personal data that the work needs. |
| C3 | strictly confidential | The highest protection need. Content stays with models that run under your organisation's control. |

## What the data class controls

### Which models may read the content

Each model under **Settings**, then **Models** has a list of **Allowed data classes**. Chat answers in a room, and the reading of files imported into it, use only models that allow the room's class.

* If someone picks a model that the room's class does not allow, Ainomos blocks the request with "Model not approved for this data class".
* Each model also has a **Residency**: **In cluster**, **Customer cloud** or **External**. An external model cannot be allowed for C3 unless a platform admin gives an override reason, which the audit records prominently.
* When an external model answers, the chat shows **Outside EU/CH** next to it, with the provider and the place of processing.
* **Coverage by data class** on the Models page shows how many models and rooms each class has. "Nobody can chat here" marks a class whose rooms have no allowed model.

A C3 room goes further. All background work for it, such as dreaming and making its content searchable, uses only models allowed for C3. If no chat model is allowed for C3, the room is paused and says so. If no model that makes text searchable is allowed for C3, the room's content is not indexed and nothing is sent to a model until one is connected.

### How personal data is handled

By default, C1 rooms keep personal data out. Ainomos withholds an answer that contains personal data, and masks personal data in documents imported into the room. In C2 and C3 rooms, personal data is allowed. C0 is meant for content without protected data, and Ainomos does not withhold answers there by default.

C1 is the default for the whole installation. Whoever runs your installation can extend this to other classes. It is not a setting in the app. See [Personal data](https://docs.ainomos.ch/privacy/personal-data.md).

### Whether originals are kept

In rooms that keep personal data out, imports never keep the original file, because it would hold the personal data that was masked in the text. In other rooms, Ainomos keeps originals of PDF and Markdown documents when your organisation has set up [file storage](https://docs.ainomos.ch/admin/file-storage.md).

## Choose a data class

Ask these questions about the content the room will hold:

* **Is it a trial with made-up or public material?** Choose C0.
* **Is it ordinary internal working knowledge, without personal data people need in answers?** Choose C1.
* **Do answers need to name people, customers or employees, or is the content confidential?** Choose C2. In C1, answers that contain personal data are withheld.
* **Must the content never reach a model outside your control?** Choose C3. Connect and allow an internal model for C3 first, or the room is paused.

> [!TIP]
>
> Before you create a C3 room, check **Coverage by data class** under **Settings**, then **Models**. A C3 room without an allowed model cannot answer.

## Who sets the data class

You choose the **Data class** in the dialog that creates a room. Choosing C0 shows a reminder that the class is for trials without protected data only.

| Way | Who can do it |
| - | - |
| Create a room with **New Room** | Platform admins, and the owner of the parent room |
| Request a room with **Request Room** | Members of the parent room. A platform admin or the parent room's owner approves the request, including its class. |
| First setup | The setup creates its department rooms as C1. |

See [Rooms](https://docs.ainomos.ch/admin/rooms.md) for creating and requesting rooms.

## Changing the data class

A room's data class is fixed when the room is created. Nobody can change it afterwards, not even a platform admin, and existing content keeps the handling of the class it was added under.

If content needs a different class, create a new room with that class and import the documents there.

## Where you see the data class

* The room picker shows each room's name together with its class.
* The room's details list the class under **Data class**.
* In the chat, the room's context states that its data class decides which models may answer there.

## Related

* [Personal data](https://docs.ainomos.ch/privacy/personal-data.md)
* [Models overview](https://docs.ainomos.ch/models/overview.md)
* [Rooms](https://docs.ainomos.ch/admin/rooms.md)
* [Import documents](https://docs.ainomos.ch/import/documents.md)


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