Skip to content

Offer-Safety means At least/at most #1275

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Apr 10, 2025
Merged

Offer-Safety means At least/at most #1275

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 12 additions & 4 deletions main/guides/zoe/offer-safety.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,8 +2,9 @@

<Zoe-Version/>

**Definition**: _Offer safety_ means that the user is guaranteed to either
get what they wanted or get back a full refund of what they offered.
**Definition**: _Offer safety_ means that the user is guaranteed to either
get **at least what they wanted**, or get back a **full refund** of what they offered — and **never worse**.
They can receive more than they asked for, but never less than promised, and they will never lose more than they offered.

For Zoe to enforce offer safety, the user must
give Zoe a `proposal`. This is a description of both what they want and what
Expand Down Expand Up @@ -32,8 +33,15 @@ escrow my offer, as Zoe immediately escrows the `give:`-specified payment.

After the user escrows, they get a promise for a payout from Zoe.
This is the payout that offer safety is enforced over. The payout _must_
be either what the user wanted (an event ticket in the above example)
or a full refund of what they escrowed ($100 in this example).
include either at least what the user wanted (an event ticket in the above
example) or a full refund of what they escrowed ($100 in this example).
Sometimes the contract will provide _more_ than I asked for (e.g., an
upgraded ticket or an additional item).

Zoe doesn't allow the contract to take any of the `give` amount from the user
unless the user receives at least their `want` amount. The contract could
also return the entire payment, along with a general admission ticket if
the requested ticket isn't available.

We can enforce offer safety because Zoe controls the payout. In the example,
if I try to buy my event ticket using a smart contract on Zoe, the contract
Expand Down
Loading