Nunchuk

• Name: Nunchuk
• URL: https://nunchuk.io/
• Category: collaborative bitcoin custody operator / inheritance-and-recovery company / advisor-facing multisig workflow control layer
• Tags: bitcoin-ecosystem
• Summary: Nunchuk belongs as an entity note, not a protocol note. The useful question is not only how a multisig wallet works. The practical control surface sits with the named company that runs platform-key policy, cloud-backed wallet-configuration recovery, inheritance-plan setup and notification workflow, advisor onboarding, and the support shell around the nominally self-custodial key design.
• What it does:
  • Operates a multisig Bitcoin wallet and collaborative-custody platform aimed at individuals, families, businesses, and advisors rather than only shipping a static wallet binary
  • Packages cloud-backed wallet-configuration backup, assisted recovery, in-app support, personal-node pairing, and configurable platform-key spending limits and co-signing delays inside the same operating shell
  • Offers inheritance products built around a dedicated inheritance key and an on-chain timelock path where the platform key is removed after expiry, alongside guided claims and notification tooling for heirs
  • Runs Byzantine, an advisor-facing collaborative-custody program where clients retain control while an advisor holds a backup key and inheritance planning remains part of the default workflow
  • Publishes developer and automation surfaces through its developer portal, GitHub organization, and CLI, which makes Nunchuk more than an end-user wallet brand
• Key claims:
  • The homepage says Nunchuk is the first Bitcoin inheritance solution designed to outlive the company that created it, which is unusually explicit language about why the company boundary matters here
  • The platform page says Nunchuk was created both to make multisig easier and to create an easy way for Bitcoiners to pass on their wealth, showing that inheritance and assisted operation are core design goals rather than optional extras
  • The same platform page says wallet configuration is securely backed up in the cloud, assisted recovery is available on a new device, in-app chat support exists, and users can configure platform-key spending limits plus co-signing delays
  • The inheritance page says We can't move your bitcoin, explains that Nunchuk holds only one key, and says that after the timelock expires the wallet’s rules change on-chain so the platform key is removed and the signing requirement drops
  • The inheritance materials also emphasize beneficiary notifications, customizable messages, and guided-claim workflow, which makes the company-run continuity lane analytically important even though the final claim path can be sovereign
  • The Byzantine page says clients retain full control of their bitcoin while the advisor holds a backup key and access is offered to a select set of advisors, which is a clear operator and admission boundary rather than a neutral software primitive
• Whitepaper: No classic standalone whitepaper is the point here. The clearest current primary materials are the official homepage, platform and inheritance pages, the Byzantine advisor page, and the refreshed source snapshot in ../whitepapers/nunchuk-company-primary-sources-2026-08-09.md.
• Sources:
  • https://nunchuk.io/
  • https://nunchuk.io/platform
  • https://nunchuk.io/inheritance
  • https://nunchuk.io/byzantine
  • https://developer.nunchuk.io/
  • https://github.com/nunchuk-io
  • https://github.com/nunchuk-io/nunchuk-cli

Internal linkages

• Project-layer alias: nunchuk.
• Strongest collaborative-custody comparisons: casa and unchained.
• Useful recovery-side contrast where insurance and underwriting do more of the work: anchorwatch.
• Mechanism contrast once you want a more policy-script-centered design with less company-run coordination: revault.

Protocol / company boundary

• There is no especially useful neutral Nunchuk protocol boundary doing the main analytical work.
• The meaningful split is between the user-facing wallet and inheritance product surface in nunchuk and the broader Nunchuk company shell that controls platform-key behavior, guided recovery, advisor-program access, beneficiary notifications, support workflow, and software distribution.
• That is why Nunchuk belongs in companies/: practical authority sits in an operating entity and its continuity promises, not just in the multisig script template.

Control surface

• Practical authority sits in platform-key spending-limit and co-sign-delay policy, cloud-backed wallet-configuration recovery, inheritance-plan setup and guided-claim workflow, advisor-program admission, notification defaults, in-app support, and the published recovery playbooks users are expected to rely on.

• The company cannot usually spend customer bitcoin alone, but that is not the right test. If Nunchuk still governs the recovery lane, inheritance choreography, advisor-facing operating model, and most convenient continuity path, the entity boundary is part of the live security model.

• Treat Nunchuk as a collaborative-custody and inheritance operating company first. The wallet matters, but the company-run recovery and succession shell is where most practical leverage lives.

• Last reviewed: 2026-08-09 UTC