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

# Make your first call

> Verify your credentials and base URL by making an authenticated request to the document groups endpoint.

## Prerequisites

* API credentials from your Nitro delivery team - see [Platform Access](/docs/nsev/getting-started/basic-setup)
* Your tenant's base URL

<Tip>
  **Prefer an interactive panel?** On any API reference page, click **Try it** to open the request
  panel, set your base URL and authentication, and send the request live against your tenant - no
  `curl` required.
</Tip>

## Set your base URL

Set your base URL as an environment variable. All examples on this page use `BASE_URL`:

```bash theme={null}
export BASE_URL="https://your-tenant.sign.gonitro.com/esig/webportalapi/v4"
```

## Make the request

Call [`GET /documentGroups`](/docs/nsev/api-reference/configuration/list-document-groups) - a read-only
endpoint that returns the available document groups. It is a safe way to verify that your
credentials and base URL are correct.

<CodeGroup>
  ```bash Basic Auth theme={null}
  curl "$BASE_URL/documentGroups" \
    -H "Authorization: Basic $(echo -n 'username:password' | base64)" \
    -H "User-Agent: MyApp/1.0"
  ```

  ```bash OAuth2 theme={null}
  curl "$BASE_URL/documentGroups" \
    -H "Authorization: Bearer {access_token}" \
    -H "User-Agent: MyApp/1.0"
  ```
</CodeGroup>

See [Authentication](/docs/nsev/authentication/credentials) for how
each method works and which OAuth2 flow applies to your integration.

## Verify the response

A successful response returns the configured document groups:

```json theme={null}
{
  "DocumentGroups": [
    {
      "Name": "My Documents",
      "Code": "00001"
    }
  ]
}
```

## Troubleshoot common errors

| Response           | Likely cause                                                                                                          |
| ------------------ | --------------------------------------------------------------------------------------------------------------------- |
| `401 Unauthorized` | Credentials are incorrect or the `Authorization` header is malformed                                                  |
| `404 Not Found`    | Base URL is wrong - make sure the path includes the `esig` segment, and double-check the host with your delivery team |
| Connection refused | Wrong host or port - confirm your base URL                                                                            |

## Next steps

<Card title="Send a document for signing" icon="file-signature" href="/docs/nsev/build/tutorials/send-for-signing">
  Follow the end-to-end tutorial to build your first signing workflow.
</Card>