Beginner path
What an auction hold is, in plain words, and a six step route through the docs for someone new to all of it.
The idea in one minute
Think of a hotel. When you check in, the hotel does not take the money for your stay. It puts a hold on your card for an amount that covers the stay. The money is still yours, but you cannot spend that part, and the hotel is promised it. When you check out, the hotel takes the real amount, and the rest of the hold goes away.
GAVEL runs an auction the same way. When you join, you choose a ceiling (the most you are willing to bid). PayPal puts a hold for that ceiling. Every bid you make is inside it. When the hammer falls, only the winner is charged, and only the winning price. Everyone else's hold is released, so they never pay.
The three pictures used on every page: hatched means held, solid means charged, hollow means released.
Six steps
Read the promise
Open Start here for the one-page version of what GAVEL does and what it does not do.
Learn six words
Read concepts: bid, hold, hammer, capture, void and journal.
Watch a bid happen
Follow the money flow to see a hold become a charge for the winner and a release for everyone else.
See what happens when things break
Crash recovery explains how a server that stops in the middle of a settlement picks up without charging twice.
Check what is proven
Status and the gates say which parts ran on the PayPal sandbox, which ran only against a fake PayPal, and which were simulated.
Try it or go deeper
The demo guide walks through a room. The architecture and the glossary are next.
Words you will meet
The most a bidder may bid in one auction. The hold is for this amount.
PayPal's practice environment. It behaves like PayPal but moves no real money.
A stand-in written for tests. Results against it say how our code behaves, not how PayPal behaves.
A bid near the end extends the lot, so an auction does not end on a last-second bid.
The step-by-step settlement after the hammer: read the truth, capture the winner, void the rest. It saves its state before each step so a crash does not lose its place.
Safe to repeat. Each PayPal call carries a request id, so sending it twice has the effect of once.
Spoken bids are not accepted silently. The bidder is asked to confirm, because speech-to-text accuracy did not clear gate G5.
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