What is Heirloom?
Heirloom solves one of Bitcoin’s most overlooked problems: what happens to your Bitcoin when you can’t access it? An estimated 3–4 million Bitcoin are permanently lost. A growing portion of that loss is due to holder death or incapacitation without any succession plan. Existing solutions all require compromises — seed phrase sharing, multisig complexity, centralized custody, or expensive legal processes. Heirloom resolves the core tension: it keeps custody in the owner’s hands while making inheritance automatic and trustless.Heirloom is deployed on Stacks testnet at contract
heirloom-vault-v10. All vault operations settle with Bitcoin finality on Layer 1.How it works
Heirloom introduces liveness-based asset release — a mechanism where vault state is determined by the owner’s continued activity, not a fixed calendar date.Create a vault
Lock sBTC and/or USDCx into a Clarity smart contract. Set a heartbeat interval (how often you check in) and a grace period (how long heirs wait after a missed heartbeat).
Designate heirs
Add up to 10 beneficiary addresses with percentage splits totaling 100%. Optionally appoint a guardian who can extend the grace period once by 30 days.
Maintain your heartbeat
Periodically sign a
heartbeat() transaction from your wallet. This resets the countdown and keeps the vault locked. As long as heartbeats arrive, your assets stay protected.Key features
Multi-asset vaults
Lock both sBTC (Bitcoin-backed) and USDCx (dollar-stable) in the same vault. Heirs receive proportional shares of both assets.
Configurable timing
Set your own heartbeat interval (1–365 days) and grace period (1–365 days) to match your lifestyle and risk tolerance.
Up to 10 heirs
Allocate assets across up to 10 beneficiaries using basis-point splits. Update your heir list at any time while the vault is active.
Guardian protection
An optional guardian address can pause the grace period countdown once — giving you time to recover access after hospitalization or travel.
Emergency withdrawal
You retain full control. Emergency-withdraw all assets to your wallet at any time before distribution — no waiting period.
Trustless execution
No lawyers, no custodians, no seed phrase sharing. The Clarity smart contract enforces every rule on-chain, settled by Bitcoin.
Why Stacks?
Heirloom is built on Stacks specifically because Stacks provides:stacks-block-time— Tamper-proof timestamps anchored to Bitcoin blocks. Vault expiry calculations are always accurate and manipulation-resistant.restrict-assets?/with-ft— Clarity 4’s post-condition enforcement ensures exact transfer amounts are verified within the contract itself.- Clarity safety — Clarity is interpreted (what you read is what executes), decidable (behavior verifiable before deployment), and reentrancy-safe.
- sBTC — Bitcoin-backed SIP-010 token that brings real Bitcoin value into smart contract logic.
- Bitcoin finality — All vault state transitions settle on Bitcoin L1, providing the highest security guarantees available.
No compromises
| Approach | Custody | Trustless | Technical complexity |
|---|---|---|---|
| Seed phrase in a safe | Exposed | No | Low |
| Multisig with family | Shared | Partial | High |
| Centralized custody | Surrendered | No | Low |
| Lawyers + estate planning | Surrendered | No | Medium |
| Heirloom | Owner retains | Yes | Low |
Get started
Quickstart
Set up your wallet and create your first vault in minutes.
How the heartbeat works
Understand the liveness mechanism that powers Heirloom.
Vault lifecycle
Learn the five vault states and how transitions work.
Contract reference
Explore every public function in the Heirloom smart contract.