Wrong address
There is no address to get wrong. The link is the address. You see the claim before it happens, and until it does, Undo works.
Robinhood Chain · ETH and any ERC-20
Oopsend turns a send into a claim link. The funds wait in an escrow contract, and until the link is claimed one tap takes everything back. Wrong address, wrong amount, a friend who never shows up: rewind it.
Drag the playhead. Before the claim you can always rewind.
01 The problem
On-chain transfers settle in a block and they are final. The wrong address, the wrong amount, a recipient who never opens their wallet: the money is gone or stuck. Oopsend adds the one thing a transfer never had, a window where the send can still be reversed.
There is no address to get wrong. The link is the address. You see the claim before it happens, and until it does, Undo works.
Giveaways and tips to people who do not open their wallet. Unclaimed links refund at expiry, and anyone can trigger it.
A claim is a signature, so anyone can submit it for the recipient and the signature still decides who gets paid. Until the public relayer runs, the recipient or a friend submits it and pays a fraction of a cent of gas.
02 The mechanism
Every send is its own record in one contract. It can end exactly three ways, and each ending is a single function call. Pick one and watch the tracks.
03 Guarantees
Funds can only go to three places: the recipient the claim signature names, the fee accrual, and back to the sender. These attacks run live below, against the same rules as the contract, with real secp256k1 signatures and the real error selectors.
These are the rules of Oopsend.sol replayed in your browser. The Solidity itself is tested with 30 Foundry tests, including a run against real USDG on chain 4663. Open the lab to attack your own link →
04 Fees and burn
0.3% of a send, taken only if the link is claimed. Undo and expiry cost nothing. Every claim fee goes to one public wallet that buys back and burns $OOPS.
05 Where it stands
Where each piece stands. The contract is deployed on Robinhood Chain and has been exercised there with real transactions.
| Piece | State | What exists |
|---|---|---|
| Escrow contract | Live | Oopsend.sol at 0x7B530e91D9dc24C78Ca2eEE2B494E7dE1B680AC0 on chain 4663: ETH and ERC-20, claim, undo, expiry, fee accrual. 30 Foundry tests, a fork test with real USDG, and a live check on the real chain. |
| Rules engine and lab | Running | A JavaScript port of the contract rules, checked against Solidity test vectors. Powers the lab and the attacks above. |
| App: send, undo, claim | Live | app.html and claim.html connect your wallet and use the contract. Tested end to end against the real contract. |
| Docs | Written | Contract reference, link format, errors, security model, examples, FAQ. |
| Gasless claim relayer | Design | A relayer pays gas so recipients need no ETH. The signature already binds the recipient, so the relayer cannot redirect funds. |
| Undo from X | Design | Tweet @UseOopsend undo <link> and get a one-tap undo page. The bot can never sign for you. |
| On-chain buyback | Design | V1 burns are run from a public wallet with every transaction posted. V2 moves the buyback into a contract. |
06 Questions
Yes, as long as the recipient has not claimed. After a claim the funds are theirs and nobody can reverse that. That line is exactly what the Final zone on the timeline shows.
At expiry anyone can trigger the refund and it goes back to you in full. You can also undo yourself at any time, even after expiry, as long as nobody claimed.
The contract has no withdraw function. Funds leave only to the recipient the claim signature names, to the fee accrual (at most 1%, locked when you create the link), or back to you. The admin can tune the fee up to 1%, change caps and pause new links. Pausing never blocks undo or claim.
Whoever holds the full link can claim, so treat it like cash until it is claimed, or undo it. The secret lives in the part after the # which browsers never send to a server. Per-link caps limit the damage of a leak.
They need an address to receive to. The claim is a signature from the link that anyone can submit, and the signature names the recipient so nobody can redirect it. Oopsend's own relayer is not running yet, so for now the recipient (or a friend) submits it and pays a fraction of a cent of gas.
ETH and standard ERC-20 tokens, memecoins from Pons included. Fee-on-transfer tokens are handled by recording what actually arrived. Rebasing tokens and tokens that can freeze or block transfers are not safe to send, see the security page.