LeanScience / bitcoin-submittx

Stand-alone Bitcoin transaction submission tool

What is this?

This is a stand-alone P2P transaction submission tool.

The motivation for this command is the -walletbroadcast=0 command introduced in Bitcoin Core 0.11 (see the release notes.)

Usage

Usage:

usage: bitcoin-submittx [-h] [--proxy PROXY] [--timeout TIMEOUT] [--no-color]
                        [--nodes-file NODES_FILE] [--tx-file TX_FILE]
                        NETWORK TXHEX [NODES [NODES ...]]

Transaction submission tool

positional arguments:
  NETWORK               Network to connect to (mainnet, regtest, testnet).
                        This also determines the default port
  TXHEX                 Serialized transactions to broadcast, separated by
                        commas
  NODES                 Nodes to connect to, denoted either host or host:port

optional arguments:
  -h, --help            show this help message and exit
  --proxy PROXY, -p PROXY
                        SOCKS5 proxy to connect through
  --timeout TIMEOUT, -t TIMEOUT
                        Number of seconds to wait before disconnecting from
                        nodes (default is 10)
  --no-color            Use no terminal color in output
  --nodes-file NODES_FILE, -n NODES_FILE
                        Read list of nodes from file (format: one per line)
  --tx-file TX_FILE, -r TX_FILE
                        Read list of transactions from file (format: one per
                        line)

The tool will connect to the provided nodes and announce the transactions. If the nodes subsequently request them within the timeout, they are sent.

The return status of the program will be 0 if at least one node requested the transaction, and 1 otherwise.

Example w/ Bitcoin Core

• Send the transaction as normal, either e.g. through RPC sendtoaddress or the GUI

$ bitcoin-cli sendtoaddress mjqhocRebTHZRhkbkQs8Uzzb1T3GhEvEB4 0.25
f91948e5...

• Using the transaction hash, retrieve the transaction data through RPC using gettransaction (NOT getrawtransaction). The hex field of the result will contain the raw hexadecimal representation of the transaction

$ bitcoin-cli gettransaction f91948e5...
{
  ...
  "txid": "f91948e5...",
  ...
  "hex": "010000000..."
}

• Provide the hex field as TXHEX to this tool. e.g.

$ bitcoin-submittx mainnet '010000000...' 127.0.0.1

(normally one would not submit the transaction to the localhost node, but this is just an illustrative example)

TODOs and contribution ideas

• Automatically fetch list of nodes to submit to
  • possibly from DNS seeds (but this won't work behind Tor)
• IPv6 support
• Provide feedback if the transaction is rejected, apart from

   recv msg_reject(messsage=tx, ccode=@, reason=non-final)

• Tor stream isolation (like -proxyrandomize in Bitcoin Core)
• Multi-hop proxies, different proxy types?
• Feature to handle incoming connections: can be handy when submitting transactions to nodes that are not listening for e.g. testing

Dependencies

• python-bitcoinlib, also available via pypi: pip install python-bitcoinlib