OP_Return in transactions at json_rpc_api at blockchain.info I am writing a project in Ruby using JSON-RPC to communicate with blockchain.info. The API is available here: https://blockchain.info/api/json_rpc_api

Is it possible to create a op_return txout using the given JSON-RPC API ?
Blockchain.info and bitoind/qt out of the box doesn't support pushing transaction out with the OP_RETURN op code. They will mark the transaction as invalid and refuse to broadcast it.

I have an open source project with a program that will push out transactions to the network directly at https://github.com/kaykurokawa/pushtx.  It doesn't do any error checking on the transaction so transactions with OP_RETURN will get relayed.

I've successfully used this in combination with pybitcointools for crafting a transaction with OP_RETURN in it.