Tools to test out replace-by-fee functionality. You'll need a local node with the replace-by-fee patch. A version applied to Bitcoin Core v0.9.1 is available at https://github.com/petertodd/bitcoin/tree/replace-by-fee-v0.9.1

WARNING: These tools were quickly written and are poorly tested. Don't use them on a wallet with a lot of funds in it. I recommend trying them out on testnet and/or in dry-run mode, as well as reading the source-code to understand what they are doing. What they are doing may not be what I intended them to do!

Requirements: Python3 (python-bitcoinlib included in repo as subtree)

Basic usage:

./bump-fee.py <txid>

Increases the fee on a transaction by double-spending it with a second transaction paying the original recipients. The change output will have its value reduced to make the fee higher, and there may be additional inputs added if the original inputs weren't enough.

Basic usage:

./double-spend.py <address> <amount>

Creates two transactions in succession. The first pays the specified amount to the specified address. The second double-spends that transaction with a transaction with higher fees, paying only the change address. In addition you can optionally specify that the first transaction additional OP-RETURN, multisig, and "blacklisted" address outputs. Some miners won't accept transactions with these output types; those miners will accept the second double-spend transaction, helping you achieve a succesful double-spend.