Dear all, sorry for my non-native English.

I post here asking for suggestions being that google and stackoverflow did not help me clarifying my doubts.

I had a web site where I can send and receive Bitcoins.

To archive this I used Blockchain API to process notifications of received Bitcoins and the same to process sending Bitcoin to other addresses.

Due to the fact that Blockchain forced me to change my calling method because they changed the API using node.js I was considering to move away from them. However I found lots of issues. The Blockchain wallet can be exported to multibit-hd and the source code is available but due to my limit knowledge of Java I am not able do replicate the same use case flow. Also, due to the fact that multibit-hd does not run as a service I cannot use it on a vps server being that in case of restart the program does not start automatically.

So I tried to use Bitcoinj directly to process payments the software performs the following steps:

• I create a new wallet with a new address.
  When the software starts it ask via web services the remote site to see if there is some payments do be send to other addresses create a transaction and then process it. But again due to my limit knowledge of Java I was not able to intercept the payment received on the address of the wallet.

I had also a problem because on the testnet the software works but when I move to production network the program seems to start downloading all the Blockchain.

Being that I am much better at C# I also tried to use NBitcoin but again with no success.

So I Google a while and found that it is possible to run Bitcoin core and use rpc call to process payment but Bitcoin-core need first to download and validate all the Blockchain that is nearly 91GB.

So my question is this:

• What I need is to code a service that uses a local wallet on a vps server (nix or win does not matter) with only a Blockchain address.
  When a new payment is received in the address the program gets the amount of the transaction and communicate it to a website using web-service.
  Programmatically the same software asks the website if new sending payment should be processed and in this case send the Bitcoin from the address.
  

The limitations are the following

• I do not want to use third party services or APIs like Blockchain or Coinbase.
  I do not want to download and process all the Blockchain.
  

Out there is there anyone that have faces the same difficulties and that can give some suggestions?
Thanks for any help

Dear All,

sorry for the long intro but I google a while and I do not find any satisfactory answer.

I have a website where I can send / receive bitcoin.

I used blockchain api with a wallet for processing the transactions.

However, due to the fact that in the last months blockchain changed the authentication API for processing the transactions, I was wondering if I could build my own processing system.

Due to the fact that I had some experience in java and that it is possible to export the blockchain wallet to multibit I tried this solution:

download multibit-hd
export my wallet
try to include in multibit-hd a client web service that was able to download the whole list of transactions in and out and process them.

However, I am not so skilled to code this. So here is the question:

I would like to know it there is out there a simple open source (better GPL) client in java or .net that is able to send / receive a transaction from a bitcoin address in a simple way so that I can code the client web service to automate the process as described.

In fact, I do not want third part API or services as I would like to avoid being dependent on a third party actor.

As a possible alternative if there is out there some command line client that is able to send / receive transaction from a bitcoin address by launching a simple command line with some parameters that would be great. I tried bitcoin core that seems to have some command line features but it need lots of storage capacity (80GB) that I do not have at the moment.

Thanks for any suggestion.

Paolo