Spinchain

SpinChain is a hybrid fitness protocol that transforms indoor cycling sessions into programmable financial events by combining the settlement capabilities of Avalanche Blockchain with the high-speed execution of Sui Blockchain. The protocol enables AI-powered fitness instructors to run autonomous spin classes with real-time biometric verification, turning workout effort into cryptographically verifiable and instantly rewardable achievements. In essence, SpinChain is “Peloton meets DeFi,” where users retain ownership of their fitness data and AI agents can operate transparent, on-chain fitness businesses.

The protocol uses the Chainlink Runtime Environment (CRE) as its decentralized trust layer for biometric verification. When a rider completes a session, CRE nodes securely retrieve private workout telemetry from wearable APIs using Confidential HTTP. These nodes execute effort-scoring logic off-chain and produce a verified report that is written back to Avalanche smart contracts for automated reward distribution. This architecture removes the need for centralized backends while preventing fraud and ensuring that sensitive API credentials remain private.

To protect user privacy, SpinChain integrates zero-knowledge proofs generated locally in the browser. Riders can prove achievements such as maintaining a heart rate above a certain threshold for a sustained period without revealing their actual biometric data. The proof confirms that the condition was met while keeping the underlying health metrics private.

SpinChain addresses three major challenges in the fitness industry: data silos that prevent users from owning their biometric information, the 30–50% revenue cuts instructors lose to centralized platforms, and the privacy-versus-verification tradeoff that forces users to expose sensitive health data to validate achievements. By combining Chainlink CRE for decentralized oracle workflows, Sui for high-frequency telemetry handling, and Avalanche for verifiable settlement, SpinChain enables a trust-minimized fitness economy where effort can be verified, rewarded, and owned by the people who generate it. 🚴‍♂️💡

SpinChain is built on a dual-chain architecture where Avalanche Blockchain C-Chain handles settlement—including reward distribution, identity management, and zero-knowledge verification—while Sui Blockchain Testnet processes high-frequency biometric telemetry at 10Hz. The frontend is a Next.js 16 application with React Three Fiber powering 3D route visualization, RainbowKit for EVM wallet connectivity, and the Sui dApp Kit for Move-based interactions. Mobile support is delivered through Capacitor for iOS and Android, with native Bluetooth Low Energy integration enabling real-time connectivity to heart rate monitors and cycling power meters.

The oracle layer is powered by the Chainlink Runtime Environment (CRE) using Confidential HTTP to securely retrieve private telemetry from wearable APIs such as Garmin and Wahoo Fitness without exposing credentials on-chain. CRE nodes listen for VerificationRequested events emitted by the BiometricOracle smart contract on the Avalanche Fuji testnet, perform off-chain computation to calculate metrics like “Qualifying Minutes” and “Effort Score,” and return verified reports to the contract to enable reward claims.

For privacy, SpinChain uses zero-knowledge proofs implemented with Noir ZK language and the Barretenberg proving system backend. Proofs are generated locally in the browser in under a second and verified on-chain through custom Solidity verifier contracts, allowing riders to prove performance thresholds without revealing their underlying biometric data.

AI capabilities are built using the Google Generative AI SDK for natural-language route generation and AI instructor personality creation. These autonomous instructors can interact with liquidity infrastructure on Uniswap v4 through custom hooks to dynamically manage class token liquidity. Decentralized storage is handled by Walrus Protocol for 3D world assets and encrypted ride session logs, while the application layer is orchestrated with Zustand for state management, Tailwind CSS for styling, and Framer Motion for interface animations, supported by pre-commit security hooks that prevent accidental exposure of secrets. 🚴‍♂️🔗