# First ID

For First ID, you need to : 

1. Subscribe to First ID
2. Activate First ID data ingestion from Websites

### **Subscribe to First ID**

1. Go to **Navigator > Settings > Organisation > Device Registries**.
2. In the **Shared device registries** section, click **Manage subscriptions**.
3. Subscribe to **First ID**.

If you have multiple datamarts, don't forget to activate First ID on all datamarts.

### **Activate First ID ingestion from websites**

First ID requires a modification of the **user-event-tag** to ingest the identifier.

Follow these steps:

1. Head to **Navigator > Settings > Datamart > Channels**.
2. Select the site where you want to activate automated First ID capture.
3. Go to **JS Tag Configuration > Device Identification**.
4. Enable **First ID**.
5. Optionally enable **Install First ID javascript tag (SDK) on the webpage**.
6. Repeat these steps for all site where First ID data collection is expected.

{% hint style="info" %}
The **Install First ID javascript tag on the webpage** option allows the mediarithmics JavaScript tag to automatically install the First ID JavaScript tag (SDK) on the webpage.

This option is optional. You may also choose to deploy and manage the First ID SDK independently on your websites.
{% endhint %}

{% hint style="warning" %}
The First ID SDK may read and write information on the device (cookies and local storage) and trigger additional processing of personal data by First ID.

Before enabling this option, make sure you have implemented all prerequisites required by First ID regarding user information and consent collection.
{% endhint %}


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# Agent Instructions: 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://developer.mediarithmics.io/user-points/user-identifiers/networks-ids/device-based-network-ids/first-id.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.