# Headers

## Authentication

{% hint style="info" %}
Authentication is done by passing your TSG Global API key via the Authorization header in the format "Authorization: Bearer \<api\_key>"
{% endhint %}

## Parameters & Content-Type

Parameters should be JSON encoded and passed in the request body (with the Content-Type header set to `application/json`). IDs are always UUIDv4. Timestamps are in the ISO8601 format and in UTC.

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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://docs.tsgglobal.com/api-reference/programmable-sms/smpp/headers.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.