How it works, at a high level:

• The sender adds coins to a zkSend link, then shares the link with the recipient via email / DM / etc.
• The recipient visits the link and clicks a button to claim the assets, without signing a transaction, or even connecting their wallet, in a non-custodial manner.

How it works, under the hood:

The sender:

• Creates a one-off Sui keypair for the zkSend link.
• Sends the assets to the keypair's address, plus a bit of SUI to pay for the claim txn fees.
• Generates a link back to the webapp such that the URL includes the keypair's private key.

The recipient:

• Reconstructs the one-off keypair from the private key found in the URL.
• Looks for assets under that address, and shows them to the user.
• Sends the assets to an address provided by the user by executing a txn from the keypair.