NonCustodialEscrow

Whitepaper · ProofRail by Talley IT LLC

A buyer-controlled, non-custodial payment escrow. Every claim in this document maps to a receipt you can verify yourself — a line of code, a passing test, or an on-chain transaction. Don't trust us. Check it.

⚠️ Testnet demo. This runs on Base Sepolia, a public test network — a working proof-of-concept, not a production system. No real money has moved through it. Mainnet use requires a professional security audit and a money-transmission review first; neither is a smart-contract question.

What it is

A smart-contract escrow for ETH or any ERC-20. A buyer locks funds earmarked for a seller, with a refund window:

Release — the buyer alone taps to pay the seller. A 1% protocol fee is taken and split 0.2% / 0.8%.
Refund — after the window, the buyer can reclaim any un-released funds.

There is no operator, no admin, no pause, no upgrade. No key held by anyone — including the deployer — can move a user's money. The buyer, and only the buyer, controls their deposit.

Guarantees — and the receipt for each

The claim	How the code enforces it	Receipt
Non-custodial — only the buyer can move their funds	`release` / `refund` require `msg.sender == payer`; no operator role exists	`test_onlyPayer_can_release`
Buyer controls release	`release(id)` is payer-only	`test_release_splits_99_02_08`
1% fee, split 0.2 / 0.8, exact to the wei	`toRecipient + feePersonal + feeReinvest == amount`, always	`test_release_splits_99_02_08` + on-chain release tx
Funds always recoverable — even if the seller's address rejects payment	Buyer can `refund` after the window, unconditionally	`test_revertingRecipient_fundsStillRecoverable`
Reentrancy-safe	EIP-1153 transient guard + checks-effects-interactions	`test_reentrancy_cannotDoubleWithdraw`
A hostile fee wallet can't freeze the escrow	Fees accrue (pull-payment), withdrawn separately — a reverting fee wallet only blocks itself	`test_revertingFeeWallet_no_longer_bricks`
No value leaks on tiny amounts	Fee rounds down; split still conserves exactly	`test_dustDeposit_conserves_noRevert`
It works on-chain	Deployed and exercised on Base Sepolia	deploy / deposit / release txs below

9 tests, all passing. Run them yourself: forge test.

What this does NOT claim

An honest document names its own edges. This escrow is deliberately simple, and here is what it does not yet do:

Not audited. The code is carefully written and adversarially tested — but careful ≠ audited. A professional audit is required before it holds real value on mainnet. Non-custodial means a bug is permanent: there is no admin to rescue funds.
The seller trusts the buyer to release. In this version the seller is paid only if the buyer taps release; a buyer who ghosts can refund after the window. A mutual-confirmation / delivery-proof design is planned but not built.
Standard tokens only. Fee-on-transfer and rebasing tokens are unsupported. Some tokens (e.g., USDC) can blacklist addresses — a blacklisted seller would block their own release (recoverable via refund).
Testnet only. Currently on Base Sepolia. Mainnet requires the audit above plus a compliant fiat on/off-ramp and money-transmission review.
Deployed vs. current source. The Base Sepolia contract below is the initial version. The source in the repository includes the pull-payment hardening; redeploying the hardened version supersedes it.

Verify it yourself

This is the entire point. Nothing here asks for your trust — it offers you proof.

Read the contract: src/NonCustodialEscrow.sol (~180 lines).
Run the tests: forge test -vv → 9 passing, including the adversarial attacks.
Inspect it on-chain: the transactions below, on Base Sepolia Basescan.

Receipts

On-chain — Base Sepolia (initial deploy):

Contract: 0x7bBF02D2E71B6e22153c3b75c09e7446AD6b9a1f
Deploy: 0xb3b4e283…883e99
Funds lock in (deposit): 0xc171e015…6aaae1
Funds release on condition: 0x78db3ebb…751526

Verified split (release tx, read back from chain):

seller 0.004950 ETH (99%)personal 0.000010 (0.2%)reinvest 0.000040 (0.8%)escrow drained