> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.qonversion.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication

> How to authenticate with the Qonversion API

The Qonversion API uses Bearer token authentication. There are two types of keys:

## Project Key

Used for standard API requests — retrieving users, properties, identities, entitlements, and creating purchases.

Find your Project Key in **Project settings** in the [Qonversion dashboard](https://dash.qonversion.io).

```bash theme={null}
curl --request GET \
  --url https://api.qonversion.io/v3/users/{id} \
  --header 'Authorization: Bearer PROJECT_KEY' \
  --header 'Content-Type: application/json'
```

<Note>
  All examples in this documentation use the Qonversion sample app Project Key (`test_PV77YHL7qnGvsdmpTs7gimsxUvY-Znl2`) for testing.
</Note>

## Secret Key

Used for advanced operations that modify user access — **granting and revoking entitlements**.

* Prefixed with `sk_`
* Found in **Project settings** in the Qonversion dashboard

<Warning>
  The Secret API key should only be stored on your server. **Never use your secret key in Android, iOS, or web apps.**
</Warning>

```bash theme={null}
curl --request POST \
  --url https://api.qonversion.io/v3/users/{user_id}/entitlements \
  --header 'Authorization: Bearer sk_YOUR_SECRET_KEY' \
  --header 'Content-Type: application/json' \
  --data '{"id": "plus", "expires": 1704067200}'
```

## Which key to use?

| Endpoint                          | Key Required   |
| --------------------------------- | -------------- |
| Retrieve / Create Users           | Project Key    |
| Retrieve / Create User Properties | Project Key    |
| Retrieve / Create Identities      | Project Key    |
| Retrieve Entitlements             | Project Key    |
| **Grant Entitlement**             | **Secret Key** |
| **Revoke Entitlement**            | **Secret Key** |
| Create Purchase                   | Project Key    |