# Authentication
To access the Poplar API you'll need to use either a **Test** or **Production** Access Token. These can be found and generated on the [**API**](https://app.heypoplar.com/credentials) page of your account:
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**Never give your Access Token to a third party**
Your Access Token can give access to your private Poplar data and should be treated like a password. If you believe your Access Token has been compromised then it can be **Revoked.**
{% endhint %}
## How to use your Access Token
To use your Token, simply provide it as part of the authorization header when you make a request. Tokens use the bearer authorization header when you make a request.
```bash
curl \
-s https://api.heypoplar.com/v1/me \
-H 'Authorization: Bearer ' \
-H 'Accept: application/json'
```
If you are using any of our client SDK's then this process is automated during initialization. This means that you do not need to specify this header explicitly.
### Testing
When creating a new access token, you have the option to create a *production* or *test* access token.
{% hint style="warning" %}
Test tokens **ONLY** work for the **mailings** endpoint**.** To test other endpoints use a production token.
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Test access tokens are intended to support the testing of API integrations and can be identified by the `test` prefix. When using a test token, mailings will be generated in your account however they will not be mailed.
From your campaigns **History** section, you can easily filter between test and production mailings:
