> ## Documentation Index
> Fetch the complete documentation index at: https://circle-devdocs-test-ai-codegen-component.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication

> Use API keys to authenticate your client requests when utilizing Circle APIs.

*API keys are unique data strings used to authenticate a user and enable access
to privileged operations on Circle APIs. All Circle APIs use API keys as the
mechanism to authenticate client requests. Your API key should be kept
confidential and secure at all times.*

* Authentication is required for all API requests; without it, the requests will
  fail.
* All API requests must be made over HTTPS.
* To obtain the API key, visit the “Developer” section in sandbox and click “get
  new API key.” Set the key in the Authorization header of the request you send
  from your backend server. Use the header format:\
  `Bearer YOUR_API_KEY`.

## API Authentication

```text API Authentication theme={null}
Authorization: Bearer YOUR_API_KEY
```

API requests without authentication will fail. It is also important to note that
all API requests must be made over HTTPS.

## Testing Authentication

To verify that your API key is correctly set up, you can use the
[get configuration info](/api-reference/circle-mint/general/get-account-config)
API endpoint, as below.

<CodeGroup>
  ```curl cURL theme={null}
  # Replace ${YOUR_API_KEY} with your API key
  curl -H 'Accept: application/json' \
    -H "Authorization: Bearer ${YOUR_API_KEY}" \
    -X GET --url https://api-sandbox.circle.com/v1/configuration
  ```

  ```javascript Javascript theme={null}
  /**
   * See installation instructions at
   * https://developers.circle.com/circle-mint/circle-sdks
   */
  import { Circle, CircleEnvironments } from "@circle-fin/circle-sdk";

  const circle = new Circle("<your-api-key>", CircleEnvironments.sandbox);

  async function getAccountConfig() {
    const configResp = await circle.management.getAccountConfig();
    console.log(configResp.data);
  }
  getAccountConfig();
  ```
</CodeGroup>

Successful Response:

```json JSON theme={null}
{ "data": { "payments": { "masterWalletId": "1234567890" } } }
```

Error Response:

```json JSON theme={null}
{
  "code": 401,
  "message": "Malformed authorization. Are the credentials properly encoded?"
}
```