How it works

The purpose of Daimo Pay is to offer the best, highest-converting way to pay or deposit crypto. This page explains how our smart contracts accomplish this.

Seamless cross-chain, any-token payments have been a long-standing technical challenge. Existing automated bridging and swapping solutions are plagued with issues, such as lost funds, clunky UX, and bad tech.

We've built what we believe is the gold standard for cross-chain payments: fast, UX-friendly, secure, and trust-minimized.

Motivation

Here are the design goals for our contract system:

• Any coin, any chain. If Alice has enough crypto anywhere, she should be able to pay or use your dapp in one click. Swapping and bridging is entirely abstracted.
• Single action. Only one wallet pop-up to transfer funds. This feels smoother than the typical approve-then-send double action. Fewer clicks, fewer spinners.
• Max speed. Payments should feel immediate. As soon as Alice’s payment lands, a liquidity provider completes the transaction on the destination chain, typically two seconds or less.
• Trustless. The simplest way to achieve 1-3 would be for Alice to simply send funds to the LP, trusting them. We designed our system without a need for trusted custodians.
• COMING SOON Gasless. Daimo Pay is already gasless in the sense that a user does not need to swap, bridge, or acquire destination chain gas. In future, we’ll support paying even if you don’t hold gas funds on the source chain, with a single permit signature.
• COMING SOON Recurring. Subscriptions, initiated in a single wallet action.

How it works

This is a lot to a do in a single wallet click! We achieve this using intent addresses.

An intent address is a smart contract that serves as a receiving address: it accomplishes a specific goal just by sending assets to it. Using Ethereum’s CREATE2 mechanism, we can make one address that works on all EVM chains. Daimo Pay encodes all the parameters of the payment, including amount, destination chain, and optionally a destination contract call, into the intent address.

This accomplishes our goals above. Alice only has to send a single transfer. The checkout completes immediately. The LP takes on a minimal amount of settlement risk to instantly yet trustlessly complete the payment specified by the intent address parameters.

Bridging

Daimo Pay uses USDC via CCTP as the underlying bridge for cross-chain payments. CCTP is free, simple, and requires no additional counterparty risk since it is operated directly by Circle, the issuer of USDC.

Neither Daimo nor LPs ever control user funds. The contract only allows the exact flow illustrated above: from the moment Alice sends funds to the intent address, those funds are guaranteed to end up with Bob. An LP can accept some reorg and bridge settlement risk by finishing the transfer immediately in exchange for a fee specified in the intent, but if no LP does this, then Alice or Bob can themselves complete the intent permissionlessly. In short, LPs only provide speed and convenience, not trust.

Swapping

Similarly, the intent commits to the exact amount to bridge, and the exact amount of the destination transfer. This protects the payer, vendor, and the LP. By swapping to a nonvolatile token such as USDC (on the source chain) and completing immediately (on the destination chain), the LP avoids price risk during the time it takes to bridge.

This lets Daimo Pay offers a convenient interface for apps and vendors. You generate a checkout link for X token on Y chain. Your users can pay with any token on any chain.