HandShake2
Hedera and Graph-powered system enabling robots to facilitate x402 payments for physical-world work.
Demo
About
HandShake is a platform where robots pay each other for physical world work, settled autonomously on Hedera via the x402 protocol. Robot A hands off a physical object. Robot B verifies the object's identity and legitimacy through an independent on-chain custody record indexed by The Graph, cross-checks the posted price and payee against what's physically written on the object, and only then signs and sends a real HBAR payment where no human approves the transaction. The goal is trustworthy machine-to-machine commerce for physical goods, not just digital ones.
How it's made
The payment layer is x402 over Hedera testnet, settled through the Blocky402 facilitator which was implemented by hand in Python since no official Hedera x402 SDK exists yet for that language, using hiero-sdk-python to build and sign the underlying HBAR transfer with the facilitator set as fee payer. Object verification runs on a separate ObjectCustody Solidity contract deployed to Base Sepolia, indexed by a custom subgraph on The Graph, so Robot B can independently confirm Robot A genuinely holds the object before paying, rather than trusting an HTTP claim. A physical QR sticker on each object carries its identity, price, and payee; Robot B's camera reads it directly and cross-checks it against Robot A's live quote, refusing the handoff on any mismatch. The robots themselves are JetCobot arms (Jetson + mycobot280), controlled via pymycobot, with the whole decision pipeline that includes scan, verify, quote-check, pay, while running as one script before any arm movement toward the object. Account for robot A: https://hashscan.io/testnet/account/0.0.10422144/operations?p1=1&k1=1789312060.240636104 Account for robot B: https://hashscan.io/testnet/account/0.0.10447952/operations