Bitcoin Hardware Wallet Interface (HWI) Moves Towards Retirement Amid Lack of Maintenance and Support

The Bitcoin Hardware Wallet Interface (HWI), a widely used bridge that connects wallet software to hardware signing devices, is moving towards retirement. The maintainer of HWI announced on August 18th that the project has been in maintenance mode for years and largely maintained by one person. As a result, HWI will no longer accept new devices or features beyond work needed for MuSig2.

The HWI bridge is crucial as it allows wallet software to discover hardware devices, retrieve public keys, display receive addresses, and send partially signed Bitcoin transactions to devices like Ledger, Trezor, Coldcard, BitBox, or Jade for approval and signing. However, the transition burden falls on teams that package HWI, invoke its command-line tool, or rely on it to absorb changes in devices, operating systems, and vendor protocols.

The successor candidate named is BHWI, which aims to preserve HWI-style command output with a Rust implementation. Although BHWI has made progress, including asynchronous, command-line, and WebAssembly layers, its testing lead does not indicate a production handoff. Therefore, the immediate pressure falls on teams that package HWI or rely on it for hardware-wallet operations.