Effisend: Agentic checkout for real-world commerce

At a Pudgy Penguins merchandise activation in Tokyo, shoppers used Effisend to buy real products on Solana, Ethereum, and BNB. We are bringing that physical checkout experience to Robinhood Chain, an Arbitrum-based network.

The problem we saw at the counter

A merchant needs to create a charge, know when it has been paid, and match the payment to the item sold. Meanwhile, customers arrive with assets on different networks. Asking staff or shoppers to manage those network decisions during a purchase makes onchain payments harder to use in the places where they should be most useful.

How Effisend works

The merchant creates an order in Effisend. The customer reviews the charge and confirms with a selfie and PIN. Effisend handles the supported payment route and returns a payment record linked to the merchant’s order.

The experience is designed around the moment of sale: a clear amount for the shopper, a clear paid status for the merchant, and a transaction that can be checked independently.

Evidence from physical commerce

Our Pudgy Penguins activation produced completed merchandise purchases across Solana, Ethereum, and BNB. It builds on our work in high-traffic venues, including a six-month residency at Tokyo Dome City and more than 1,000 users onboarded to Effisend.

Those purchases establish demand for the checkout. They should not be confused with Robinhood Chain sales: Robinhood Chain is integrated into Effisend, but it has not recorded a customer purchase yet.

What we are building for Arbitrum Open House

We have added Robinhood Chain as a payment route in the merchant checkout. Our goal is to take a flow already used for real purchases and make it work for customers on this new network, with a merchant order and an independently verifiable transaction at the end.

Our next measurable milestone is the first independent customer purchase on Robinhood Chain. We also plan to bring the same checkout to Arbitrum One, with each network’s transactions and merchant records clearly identified.

Effisend gives the Arbitrum ecosystem a path into physical commerce through an existing product, venue experience, and merchant use case. The submitted demo shows the Robinhood checkout; the repository documents the build.

Real sales, real numbers:

Technical evidence

Network: Robinhood Chain mainnet (chain ID 4663). Not testnet.

Live app: effisend-tdc.expo.app

Deployed contract: Effi NFT (ERC-721, EffisendNFT.sol)

| Address | 0xDDa30795FF04677C1c4B58616b7b77503554DC97 |

| Explorer | [robin.etherscan.io](https://robin.etherscan.io/address/0xDDa30795FF04677C1c4B58616b7b77503554DC97) |

| Verified | On-chain bytecode matches Contracts/contracts/EffisendNFT.sol byte for byte (solc 0.8.28, optimizer 200 runs, evmVersion: cancun) |

Transactions on Robinhood Chain mainnet

All of them were made through the live app.

| Action | Amount | Transaction |

| Face ID checkout | 0.009999 USDG | 0x06c2…b604](https://robin.etherscan.io/tx/0x06c2a265a34f4df6c743208f2829e58ffa89b69a96d53de529689ee4fba8b604) |

| Robinhood Pay | 0.01 USDG | 0x9461…607a](https://robin.etherscan.io/tx/0x94611b2590778ac952ef9b365e2aa0c82d4532b51d14ce55776b71e56dea607a) |

| Card top-up (USDG out of Robinhood via LI.FI) | USDG | 0xc9bd…8a75](https://robin.etherscan.io/tx/0xc9bdb0d58abc5e118317dd58ce53aacd40db4b8e5c362f8b481e78e51baf8a75) |

| ↳ Arrival as USDC on Linea | USDC | 0x3ca8…713e](https://lineascan.build/tx/0x3ca8e0b83a2fc192741f64669fe91287031cf6b34de408cf91eb209cf234713e) |

| Effi NFT delivered with distribute() | 1 NFT | 0x470f…2d82](https://robin.etherscan.io/tx/0x470f2546765b6f153ddd4eab91a92479aed53e8b3b2634b507cdb04a3daf2d82) |

Commits during the buildathon

[Full history →](https://github.com/altaga/Effisend-RH/commits/main)