Any way to tell what text message another message is in response to?

Are there any texting services out there (like Twilio) with APIs that allow you to see what message another message is in response to? For example: I want to tell whether message 3 is in response to 1 or 2.

1. A->B: Do you like ice cream?
2. A->B: Do you like pizza?
3. B->A: Yes.

I'm guessing that there's just no threadedness to text messages, and this is impossible. But might as well have a canonical answer out there.... Reasons for this belief:

1. When you send emails to a phone number at txt.att.net, it uses a different number each time.
2. The texting services that I've looked at don't offer the feature
3. The phone UIs I've used all present it as a flat message list rather than a threaded list

Ca开发者_如何学Gon someone confirm this?

There is no native support for this type of functionality in SMS. Message threading for SMS is inferred on the client side from context. When I send a text to person 1, if I receive a reply from person 1 within a given time-frame, I can assume that it was part of the same "conversation". (I actually implemented something like this for a chat client that I was working on)

I have also seen where the original message is included with the response, and the client can group the messages accordingly (take a look at gmail), but this could be messy if your clients were not the same.

Just a few thoughts.