TextP2P provides an HTTP POST API which anyone can call to remove existing contacts from an existing list in TextP2P. This can be called from an application / CRM like Infusionsoft, Salesforce, etc.
By going to your list and clicking the ACTION button at the top right, you will then see "Api Webwook" which you can click and it will pop-up a window which will give you a unique url webhook for your list.
The application should make a http post using the following post parameters below.
WHID = abkd9388 (This is the webhook list id)
AUTH_USERNAME - comes from the TextP2P Application screen
AUTH_SECRET - comes from the TextP2P Application screen
PHONE = 5554442272
If successful it will return an http response code of 200. An error will return 400 or 404.
curl -v -d "PHONE=5713152111" 'https://app.textp2p.com/remove-from-list-webhook.php?whid=f638741f&AUTH_USERNAMEemail@example.com&AUTH_SECRET=59c33016884a87455be975a9bb1234f5'