Level 1
Whoever Moves First Gets Robbed
Two strangers, one job, no trust. Before any machinery exists, feel the standoff that makes the machinery necessary.
Needs: nothing. Start here.
Level 2
The Middleman Can Be Bought
The obvious fix is a trusted person in the middle, holding the money. Watch what a person in that seat can do.
Needs: nothing beyond Level 1.
Level 3
A Box Made of Rules
Fire the person. Keep the holding. Replace the middleman with rules anyone can read and no one — not even the maker — can reach into.
Needs: nothing beyond Level 2.
Level 4
A Picture Can Lie
The box believed a screenshot. Never again: from now on it demands evidence it can re-run for itself.
Needs: nothing beyond Level 3.
Level 5
The Box Has No Taste
The box only takes jobs with a yes-or-no rule — and flatly refuses everything else. That refusal is its power.
Needs: nothing beyond Level 4.
Level 6
Skin in the Game (But Only After You Say Go)
A refundable deposit makes walking away cost more than it gains — and the stranger risks nothing until the moment they say go.
Needs: nothing beyond Level 1.
Level 7
The Clock Is the Only Judge
One deal, three endings — paid, rejected, timed out — and not one of them needs a human to show up.
Needs: Levels 4 and 6.
Level 8
It Never Asked Who
Run the same deal twice — once for a human, once for a machine — and watch the box not care. This is the reveal, and the reason this page exists now.
Needs: nothing beyond Level 7.
Finale
Run One Whole Deal. Keep the Receipt Forever.
Every part you built, bolted together. Lock the money, watch the stranger opt in, pick an ending, and let the box settle it. Then keep the receipt — and try to argue with it.
Needs: the climb behind you — or the skip button and some nerve.
Under the hood — for engineers
The page above never uses trade words. If you already speak them, here is the same machine in your language.
| The page says | An engineer would say |
|---|---|
| the money, locked where neither side can touch it | escrow — funds held by the settlement contract until the rule decides |
| a refundable deposit | the worker’s bond, posted at activation |
| loses the deposit | the bond is slashed — and only on timeout; a failed check never slashes |
| the agreed check / the rule | the verifier program pinned to the task |
| the box | the settlement smart contract — an on-chain state machine |
| the fingerprint of this job, these inputs, this answer | taskId, inputHash, outputHash — hash commitments carried in the proof’s public values |
| the sealed packet of evidence | a zk proof that re-runs the exact frozen check for the deal — one deal, one check, nothing widened after the fact |
| the stranger says go | activation: the worker opts in and posts the bond; risk starts here, never earlier |
| the clock fires by itself | after the deadline, the timeout call is open to anyone; the outcome is already determined — calling it just records it |
| nobody can change the rule mid-deal | the verifier allowlist is governed, but your task’s verifier is pinned when the deal starts; pausing halts new tasks, never settlement of active ones |
| the money itself | a dollar-pegged token (USDC) on an Ethereum layer-2 (Arbitrum) |
| the receipt | the on-chain settlement record and its emitted events — re-checkable by anyone, forever |
Same fences in both languages: designed and being built in the open; not audited; the strongest proof family today re-runs one narrow, frozen check.