Sending/Receiving multi-recipient SMS - Twilio API

Question

I am writing an app that will facilitate the sending and receiving of SMS messages via a web application. I would like to allow for multiple recipients (not bulk, just a few recipients at most).

I understand that in order to send to multiple recipients, I have to make multiple API calls, and that is fine. The problem I am having is receiving text messages via the Webhook callback. If the SMS was sent to multiple recipients, I cannot see the other recipients in the callback, just myself as the recipient.

Because of this, I have no idea whether this message was intended for just me, or for other recipients as well. This is a problem, because I would like to show threaded conversations similar to Google hangouts, or the SMS applications on all Andorid and iPhones.

I cannot figure out a way to track conversations, if I can't tell if a received message was sent to just me, or a group of recipients. Any suggestions? I do not yes use Twilio on a production server, so if this is not possible to do using Twilio, but is possible using another service, that would be an option for me as well.

Answer 1

Twilio developer evangelist here.

Twilio doesn't fully support group messaging the way that you are used to it when using a phone. That actually relies on MMS under the hood to keep the members of the group chat synced up.

Where you make multiple API calls to send messages to each user, that is manifested as just a single message with no group attached. Thus, any reply to that message comes solely from that person you sent the message to. There is no group at all at this point.

The link that Alex shared in the comments is the closest way you can get group messaging to work. It relies on everyone messaging one Twilio number and the application behind it fanning the messages out to all the recipients. The blog post also comes with some handy subscribe/unsubscribe administration for the group.