# Authentication (v1)

All API requests require authentication using an API token.

## Using Your Token

Include your token in the `Authorization` header:


```bash
curl -X POST "https://api.hginsights.com/data-api/v1/company/firmographic" \
  -H "Authorization: YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"domain": "example.com"}'
```

## Migrating to v2

v2 offers a simpler authentication model with entitlement-based tokens. See [v2 Authentication](/v2/guides/authentication).