The Bitcoin Core Hardware Wallet Interface, or HWI, the widely used bridge between wallet software and hardware signing devices, will no longer accept new devices or features beyond the work needed for MuSig2. The maintainer said on Aug. 18 that the project had effectively been in maintenance mode for years and had largely been a solo effort. Once the MuSig2 work is complete, the maintainer expects to make a release that will likely be the project's last, then keep HWI in minimal maintenance until a suitable drop-in replacement is ready.
Existing hardware wallets are not described as losing support, and users' bitcoin is not considered at risk. The change primarily affects the integration path for future hardware models. HWI lets wallet software discover a hardware device, retrieve public keys, display receive addresses and send partially signed Bitcoin transactions to devices such as Ledger, Trezor, Coldcard, BitBox or Jade for approval and signing.
The successor candidate named in the notice, BHWI, aims to preserve HWI-style command output with a Rust implementation, but it is still labeled work in progress. BHWI's parity documentation shows differential tests against the unmodified HWI 3.2.0 device suite for BitBox02, Coldcard, Ledger and Jade, but no wallet is yet confirmed to be shipping BHWI as a production replacement.
Downstream exposure is uneven. Bitcoin Core uses HWI as the documented example for its external-signer boundary. Specter Desktop pins HWI 3.1.0 as a direct dependency. BTCPay Server Vault wraps HWI's command line. Wasabi Wallet has tied hardware-wallet support to HWI and previously reported issues with Apple Silicon builds. Sparrow Wallet uses a separate Java-derived implementation called Lark, so it faces its own migration decision. The repository may remain open until a successor is suitable, but the contribution freeze is already in effect. The next compatibility change could force wallet teams to maintain forks, build separate integrations, or leave new hardware combinations unsupported.
