Pay to contributors

[s2]

Can anyone point to some script (ideally in nodejs or php via the RPC to bitcoind) that can read the addresses that have paid funds to a specific address?

[andytoshi]

Addresses don't pay funds. They are static identifiers for transaction outpoints, more akin to an invoice number than anything actively involved in transactions. There is a wiki article by iwilcox on this subject.

[s2]

Wow, thanks!  I never considered it bad practice refunding due to these issues.
Still it seems technically possible for the most common transaction but yes I'll start considering alternatives.
Thanks again.

[andytoshi]

If you try refunding transactions given only the information available in your receiving transactions, you will be wrong a significant amount of the time. You cannot tell "the most common transactions" from others.

[Sheldor333]

If there isn't one I am sure you can find someone to make you one if you pay them.

[andytoshi]

If there isn't one I am sure you can find someone to make you one if you pay them.

He cannot. As I have said twice now, it is not possible to do what he is asking.