YOU KEEP SIGNING. THE DAY YOU STOP, THEY INHERIT.
Walkers stack a cairn one stone at a time so the next person finds the trail. Here a stone is a signature — small, cheap, and proof you're still on the path. Stop placing them and the vault hands itself to the people you named.
SELF-CUSTODY HAS NO NEXT OF KIN.
A bank has a desk you can walk up to with a death certificate. A blockchain has no desk. Every workaround in use today trades one risk for another.
Seed in the will
Twelve words, sealed, left with the lawyer.
Keys to family now
Hand your partner or children a copy today.
Trust a custodian
A company holds it and promises to pass it on.
YOU CONTROL THE FIRST THREE.
The vault is a program on Solana. While the stones keep coming, nothing moves. The moment they stop, a long, loud, cancellable countdown begins.
You set the terms
Deposit, name your successors and their shares, choose the interval and the grace window. Change any of it, any time, while you're alive.
You place a stone
One tiny signed transaction on your schedule — the proof of life. It says nothing about you except that the key still answers.
A missing stone starts the clock
The state turns public so any notifier can warn you everywhere at once. One stone ends it and resets everything. Travelling, ill or forgetful costs you nothing.
They follow the path
Each named wallet claims its share straight from the vault. No death certificate, no probate queue — we could disappear tomorrow and the claim still works.
ONE NUMBER IS THE WHOLE PRODUCT.
Days until the next stone is due. Everything else — the grace window, the successors, the shares — you set once and don't touch again until something in your life changes.
A SWITCH YOU CAN'T AFFORD TO FLIP ISN'T A SWITCH.
Dead man's switches have existed as an idea for years. They failed for a boring reason: every stone costs money to place, forever, and on most chains that bill quietly grows past what the protection is worth.
360 stones, one a month, at roughly a tenth of a cent each. Placing one is effectively free, so nobody stops.
Same schedule, same thirty years. Now the switch has a running cost people abandon — and an abandoned switch fires while you're alive.
Illustrative arithmetic, not a quote. Solana figure assumes a 5,000-lamport base fee with SOL around $200; the comparison assumes $1–3 per contract call, ordinary on busy chains and far higher when they congest. Drawn as a bar chart the Solana column would be a hairline roughly a thousandth the height of the other, which is why we show numbers instead. Fees and prices move; the ratio is the point.
WHAT CAN GO WRONG.
This is a protocol about death, so vagueness here would be indefensible. These are the failure modes we know about, including the ones we haven't solved.
You're alive but silent
Hospital, prison, a lost phone, a long stretch without connectivity. The vault cannot tell the difference between that and death.
Mitigated, not solved: long intervals, months of grace, a publicly readable state so any notifier can reach you, cancellation with one signature. Choose your interval assuming you will one day miss one.
A successor loses their key
You name someone today. In fifteen years they lose access to that wallet. Their share becomes unclaimable.
Mitigated: name more than one, review the list when you review anything else important, and prefer wallets your people actually maintain.
Someone knows your schedule
The interval is on-chain. A person who wants what you have can read exactly how long they'd need you unable to sign.
Not solved. It's the uncomfortable cost of a trustless trigger, and it's why the vault should hold what you intend to leave behind — not everything you own.
The program must outlive all of us
An inheritance vault is only trustworthy if the code can't change after you're gone. But immutable code can never be patched either, including for a bug found later.
The plan: audit first, then permanently burn the upgrade authority before anyone is asked to trust it with real assets. Until then, devnet only, and we say so everywhere.
It is not a will
A vault moves assets. It does not settle an estate, satisfy a creditor, pay inheritance tax, or override the law where you live.
Treat it as a mechanism your will can describe, not a replacement for one. Tell your lawyer it exists; tell your successors too.
BEFORE YOU TRUST ANYTHING WITH THIS.
Is this live? Can I use it today?+
No. Cairn runs on Solana devnet and has not been audited. Nothing here holds real assets, and the program's upgrade authority has not been burned yet. Please don't put anything you care about into an unaudited inheritance vault — the irony would be considerable.
What if I miss a stone by accident?+
Nothing irreversible. The vault enters grace, which you set yourself — sixty days is a sensible default. During grace the state is publicly readable, so any notifier you or your successors set up can start reaching you. One stone resets the clock.
Can my successors take anything early?+
No. The claim instruction fails unless grace has fully elapsed without a proof of life. They can read the vault's state, but the program won't let them act before the countdown finishes.
Can I change successors or shares later?+
Yes, at any time, as long as you're the one signing. People fall in and out of your life; a vault that couldn't be updated would be worse than useless.
Do my successors need to know anything technical?+
They need a Solana wallet and they need to know the vault exists. That second part is on you, and it's the failure we can't fix in code: a vault nobody knows about is indistinguishable from a lost seed phrase. Tell them now.
Is there a token?+
Yes. $CAIRN is now live on Solana. Use only the contract address published through our official channel, @cairnvault, and verify it before trading.
PLACE THE FIRST STONE.
Set up a vault on devnet, name someone, and sign. Two minutes, and a fraction of a cent.