What makes Nunchuk different from other Bitcoin collaborative custody providers?

Our service rests on four pillars:
✅ KYC-free
✅ No single point of failure
✅ Open standards
✅ Bitcoin-focused

We committed to these pillars because of a unique experience that shaped us: our part in the Freedom Convoy incident of February 2022. When the Canadian government moved against the protesting truckers and their supporters, we were served a Mareva injunction demanding that we disclose information about our users and freeze their funds. Many services voiced support for self-custody in principle but watched from a distance, unwilling to take on the protesters as users for fear of the government’s response.

That was the moment our vision of what Nunchuk should be became clear. The question we now ask of ourselves is simple: if an entity is powerful enough to compel us to disclose information about our users and freeze their funds — could we even do it?

Can we and our clients withstand a state-level attack? And crucially, it’s not enough to be willing to say no. Our architecture has to make it so that we cannot comply in the first place.

That’s why we’re KYC-free. Your privacy is paramount. Anyone targeting you learns nothing about you even if they compromise Nunchuk, because we don’t hold that information. The one exception is that subscribers provide an email at signup (an anonymous address like Proton works fine), because we need a way to reach you during exactly the kind of security incident we just lived through. Last weekend made the case that this trade-off was the right one.

That’s why we insist on no single point of failure. In practice this means multi-vendor multisig as the foundation. For our assisted wallets, it also means the keys you hold are dedicated hardware signers (no hot key on the phone). In collaborative custody, the provider already holds one key. If the client’s other keys included a hot key running in an app the same provider maintains, a forced or malicious software update could seize a majority of keys (in a 2-of-N setup) and sweep or freeze funds. A hot key on the user’s phone would make life easier for us and our users, but it would fail the standard we set for ourselves in 2022. So we made the harder choice and disabled it entirely in our assisted wallets.

That’s why we build on open standards. In the worst case, you can always migrate your Nunchuk setup to other software that follows the same Bitcoin standards, such as Sparrow. The exit door stays permanently open, even if Nunchuk were to disappear tomorrow.

That’s why we’re Bitcoin-focused. Bitcoin is what we build for, and what we build on, including its Layer 2 system. The wider “blockchain” industry, with many centralizing points of failure, whether explicit or implicit, has proven throughout the years that it cracks under real pressure. We chose depth over breadth, and quality over quantity.

These are the reasons Nunchuk stands apart from other services.

🖥️ ☕️

The Bitcoin agent key can now live in a Coldcard Mk4/Mk5 in HSM mode.

Even if the host machine running your agent is fully compromised, the signing key stays isolated in hardware. The attacker gets nothing useful.

Bitcoin agents with bounded authority. Now with HSM-grade key security.

AI agents shouldn't get the full key to your kingdom.

Today we're releasing Nunchuk CLI: create a shared Bitcoin wallet with your agent, give it a spending budget, and keep the final say.

Build Bitcoin agents with bounded authority.