How to send faxes (or sms) from a specific phone/fax number

If you are trying to send a fax and receive the following error message, there is a relatively simple solution:

{

  "errorCode": "CMN-419",

  "message": "In order to call this API endpoint for another extension, one of

              the following permissions [OutboundFaxes] have to be granted

              with extended scope to the authorized user.",

  "permissionsName": "OutboundFaxes"

}

A version of this error message can also appear when performing other actions via the API. The root cause and remedy are almost always the same.

Other Common Scenarios for This Error

You might also encounter a version of this error when:

• Sending an SMS

• Reading messages from the message store

• Accessing a call recording

The Root Cause

This message typically indicates that a user is trying to perform an action on behalf of another user, or is attempting something that only the owner of a specific resource is authorized to do.

In simpler terms:
A user can only send an SMS or fax from a phone number assigned to them.

If a user tries to send a message or fax from a number that belongs to someone else, the system throws the CMN-419 error.

The Remedy

To avoid this error, developers need to maintain access tokens or JWT credentials for each user. Here’s an example of how that might look:

If Luke wants to send a fax from (510) 555-2468, you need to:

1. Look up which user owns that number.

2. Retrieve Han’s credentials.

3. Authenticate to the API using Han’s credentials.

4. Send the fax on his behalf.