Avoid Mixed Usage

Unlike other proxy services, VCAPI maintains its own state to provide some functionality. If used, it must be your exclusive means for managing data in your Phaxio account. Mixed usage will lead to conflicts between the data in VCAPI and in Phaxio.


VCAPI (Vitelity Compatibility API) is a Vitelity-like interface for Phaxio. While perfect compatibility with Vitelity is preferred, some minor changes have been made to account for differences with Phaxio. Any parameters which are no longer accepted will be silently ignored.

The base URL is https://vcapi.phaxio.com. All non-public endpoints accept your Phaxio API key and secret, specified as basic auth credentials. These correspond to Vitelity’s login and pass parameters. All actions must be an HTTP POST, and URLs follow the same /<CATEGORY>.php?cmd=<COMMAND> format as Vitelity.


Before using VCAPI, you must register your API credentials and update your webhook settings. This only needs to be done once. Note that your data is linked to your API credentials rather than your Phaxio account. As such, it is vital that you do not delete the API credentials from your account.

  1. Create an account with Phaxio
  2. Visit the Webhook Settings page. Update your Sent Handler to https://vcapi.phaxio.com/webhooks/sent_fax and Received Handler to https://vcapi.phaxio.com/webhooks/received_fax, ensure that inflight webhooks are disabled, and set your Webhook Version to 2.1.0.
  3. Copy your webhook token from the bottom of the page.
  4. Visit the API Keys page and copy your live API key pair (not a test pair).
  5. Send a POST request to VCAPI at the /user.php?cmd=register endpoint, passing the following parameters containing your Phaxio account information:
    • phaxio_api_key
    • phaxio_api_secret
    • phaxio_webhook_token

If you get an “OK” response, then your account was registered successfully, and you may now access the VCAPI.