mmgen-wallet/doc/release-notes/release-notes-v0.9.1.md

BIP 125 replace-by-fee (RBF) support:

• Create replaceable transactions using the --rbf switch to mmgen-txcreate and mmgen-txdo
• Create, and optionally sign and send, replacement transactions with the new mmgen-txbump command

Satoshis-per-byte format:

• Tx fees, both on the command line and at the interactive prompt, may be specified either as absolute BTC amounts or in satoshis-per-byte format (an integer followed by the letter 's')

Improved fee handling:

• Completely reworked fee-handling code with better fee checking
• default tx fee eliminated, max_tx_fee configurable in mmgen.cfg

Command scriptability:

• New --yes switch makes mmgen-txbump and mmgen-txsign fully non-interactive and mmgen-txcreate and mmgen-txsend mostly non-interactive

Bugfixes and usability improvements:

• 'mmgen-tool listaddresses' now list addresses from multiple seeds correctly
• Improved user interaction with all 'mmgen-tx*' commands

The RBF and new fee functionality are documented in the Getting Started guide.

The guide has also been updated with a new Preliminaries section and a new Hot wallets and key-address files section.