Handshake

Trust the deal, not the stranger.

AI catches the scam before money moves. PayPal holds the money until the item really arrives. Agents negotiate a fair price, and every deadline enforces itself.

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Live demo · Watch the demo (2:33) · Try it in 60 seconds · How it works · Architecture · Security · The build story

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Watch the demo

Watch on YouTube (2:33, narrated, recorded on the live site). AI stops a scam before any money moves, then an honest deal goes from listing to payout: a PayPal hold, two AI agents negotiating inside secret limits, a shipping label checked against the buyer's PayPal address, and PayPal capture and Payouts.

The problem

You find a used Nintendo Switch on Marketplace for $230. The seller is friendly and quick to reply. Then come the messages:

"Still available! I'm out of town so I'll ship it. Send it Friends & Family so there are no fees, and please do it in the next 30 minutes, two other people are asking."

Now you have to choose, and every choice is bad:

• Pay Friends & Family, and you have no protection at all. If the Switch never comes, the money is gone.
• Pay with buyer protection, and the seller may refuse, or you end up in a dispute that takes weeks while your money is stuck.
• Meet in person with cash, and you carry hundreds of dollars to meet a stranger, and still can't be sure the item works.

Honest sellers have it just as bad: fake "payment sent" screenshots, buyers who claim the box arrived empty, and chargebacks weeks after the sale.

This isn't rare. Americans reported a record $15.9B lost to fraud in 2025 (FTC), and online shopping was the #2 most reported kind of fraud in 2024. Most of it starts exactly like this, with a stranger, a good price and a little pressure.

The real problem is that trust has to come first. One side has to send money, or an item, before they know the other side is honest.

The solution: Handshake

Handshake removes that first leap of trust. It's a protected deal room for buying and selling physical goods with someone you don't know, on any marketplace, chat or forum.

1. Check the deal first. Paste the chat, a screenshot or the listing link. AI reads it for scam tricks, real store prices show whether the price is bait, and scam memory recognises sellers who have tried this before.
2. The money is held by PayPal, not sent. The buyer pays into a PayPal hold. The seller can see the money is real; nobody can take it yet.
3. Proof before payment. The seller's shipping label is read by AI and checked against the buyer's PayPal-verified address, and the parcel is followed with the carrier. Meeting in person instead? The buyer checks the item, then scans the seller's one-time code.
4. Only a fair amount ever moves. If it arrives as described, PayPal captures the payment and pays the seller. If it's damaged, a photo is priced against real replacement parts and only the fair amount is captured; the rest goes back to the buyer.

Underneath, every deadline enforces itself: a seller who never ships has the hold released automatically, and a buyer who goes quiet after a verified delivery can't keep the seller waiting forever. A day before any deadline acts, the person who has to act gets a reminder.

This is the beginning of the README. Read the rest at the original. Read the full README ↗