# HTTP

If you need to send events from an offline system or have events triggered outside your site, you can use our HTTP approach to send them.

EdgeTag operates using a server-side cookie to identify users. Therefore, it is important, if possible, to store our ID from the browser in our system. This will allow you to associate the same user when sending events via HTTP.

If the system is not connected to your website, there's no need to worry. We can also connect users via email. Please ensure that you include the email in the payload using the `userEmail` property. We will search for this email in our ID graph and connect it to the user. If the user is not found, we will create a new user.

{% hint style="info" %}
If you are using EdgeTag without a browser, you can always define your own EdgeTag ID and use that as an identifier. Example: You use EdgeTag in your mobile app, and you use mobile ID as EdgeTag ID when sending events.
{% endhint %}

### Error handling

All APIs have the same error-handling mechanism.

```java
{
  "message": "Value is not defined",
  "code": "400"
}
```


---

# 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://docs.edgetag.io/implementation/http.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.