Is it possible to use sendrawtransaction without downloading the blockchain? Or will bitcoind reject the broadcast since it can't validate the inputs?
If the client does block it by default, is there any way to force it to send it?
The RPC call sendrawtransaction tries to broadcast the raw transaction you give it by first adding it to its own mempool of transactions. If you don't have the UTXO database, then you won't be able to validate the inputs of the transaction, so your node will reject it from its mempool. So, essentially, no, there isn't a way with the default client.
You could modify your client to have a new RPC call that just sends the raw transactions without checking it. But then you run the risk of broadcasting an invalid transaction and having your peers increase your ban score.
Also see: Pushing tx to the network via AJAX, without installing bitcoin. That question lists a few APIs that have support for broadcasting a raw transaction, which may be helpful to you.
-
Ha, thats my question you linked to =). Unfortunately all those services require an API key and blockchain.info doesn't support OP_RETURN yet. – Aakil Fernandes Jun 23 '15 at 15:18
-
@AakilFernandes, I know, putting it for completeness ;) It's not usually too hard to get an API key. – morsecoder Jun 23 '15 at 15:20
-
Have a look to webbtc.com/api/relay It supports OP_RETURN afaik. And I have to say that it is VERY easy to write a program for pushing transaction to bitcoin network without any client installed – amaclin Jun 24 '15 at 10:27
