Bitcoin wallet industry faces disruption as standard interface support ends

The standard interface linking Bitcoin Core and hardware wallets, HWI (Hardware Wallet Interface), is effectively entering a wind-down process. By contrast, the Rust-based project BHWI, cited as a successor, has yet to show real-world service deployments, CryptoSlate reported on Aug. 30 local time.

An HWI maintainer said on GitHub on Aug. 18 that HWI had effectively been in maintenance mode for years and was mostly a one-person project. The maintainer said it would no longer accept new devices or features apart from work related to MuSig2. Once that work is finished, it plans to publish a release that is likely to be the last, then continue only minimal maintenance until a viable replacement tool emerges.

HWI acts as a bridge for wallet software to recognise hardware devices such as Ledger, Trezor, Coldcard, BitBox and Jade, retrieve public keys or display deposit addresses, and send partially signed bitcoin transactions (PSBT) to a device for signing. BHWI, named in the notice as a successor candidate, aims to be implemented in Rust while keeping HWI-style command output intact.

But the transition remains incomplete for both projects. HWI has not yet been moved to an archived repository and no end date has been set, and the notice does not say that supported devices will stop working or that users' bitcoin will be put at risk. The immediate burden falls on wallet development teams that have packaged HWI or called it via the command line to absorb protocol changes by device, operating system and vendor.