> For the complete documentation index, see [llms.txt](https://doc.dastra.eu/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.dastra.eu/en/features/editer-le-registre/declare-a-treatment.md).

# Declare a processing activity

## What is data processing?

A processing activity is an operation or set of operations performed on personal data, such as payroll. All processing activities taken together constitute the processing record.

## Create a processing activity

To create a processing activity, first click on "Create a data processing" in the Registry section.

<figure><img src="/files/8Tvmqcs9WCWa5Uu8KTHM" alt=""><figcaption><p>Choice of new treatment</p></figcaption></figure>

Choose the type of treatment.

Fill in the description of the treatment activity and you will be taken to the questionnaire section where you can add all the required information.

## Create a processing operation as a data processor

To create a treatment as a processor, it's very simple. When creating a processing operation, you must check the box:

<figure><img src="/files/poCr7iEAOgp8IODwMjOF" alt=""><figcaption></figcaption></figure>

You will then automatically arrive at the documentation phase of a processing operation as a data processor and you will be able to declare your data controllers (usually your customers).

## Modify a data processing

To modify an existing treatment activity, click on the "Edit" button linked to the treatment or click directly on the treatment name:

<figure><img src="/files/BcEvaYV8bJQGsDTySF5f" alt=""><figcaption></figcaption></figure>

Then follow each step of the questionnaire, starting with the next section:

{% content-ref url="/pages/-LvMDW-VMCrzSDNt2PC8" %}
[Complete a data processing activity](/en/features/editer-le-registre/remplir-le-questionnaire.md)
{% endcontent-ref %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://doc.dastra.eu/en/features/editer-le-registre/declare-a-treatment.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.