> For the complete documentation index, see [llms.txt](https://docs.truecaller.com/truecaller-sdk/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.truecaller.com/truecaller-sdk/mid-verification-sdk-api/authentication.md).

# Authentication

Two headers are required:

| Header        | Required | Description                                                      |
| ------------- | -------- | ---------------------------------------------------------------- |
| Authorization | Yes      | Bearer {token}. token is shared by BE team as one time activity. |
| appKey        | Yes      | Partner SDK app key. Must be registered as group type `MID_SDK`. |

{% hint style="info" %}
 `appKey` is further validated against the SDK registry. Apps not of type `MID_SDK` are rejected with 403.
{% endhint %}