The problem ShieldPass solves

Traditional subscription billing gives merchants unlimited, open-ended authority over your cards or wallets, leading to hidden cancellation mazes, forgotten free-trial charges, and silent price hikes.

Today, ShieldPass replaces open-ended billing with programmable, escrow-backed payment passes on Sui. Users set strict boundaries: an authorized merchant, an exact per-charge price ceiling, and an automated expiry date, before funds are locked.

It makes recurring payments safer and effortless by:

• Eliminating the "Free-Trial" Trap: Passes self-expire automatically when a trial ends, making surprise renewal charges impossible without having to navigate cancellation mazes.

• Enforcing Hard Spend Caps: Any unauthorized price hike exceeding the user's per-charge limit is instantly rejected on-chain by Move smart contract logic.

• Removing Web3 Friction: Powered by Enoki Google zkLogin, users get trustless smart-contract protection using standard Google sign-in—with zero seed phrases or complex wallet onboarding.

Challenges we ran into

Dual-Wallet Architecture & Context Mismatch:
To deliver a seedless Web2 onboarding experience, we integrated Google zkLogin via Mysten Labs' Enoki SDK. Early implementations ran into state desynchronization issues where browser redirects after Google authentication failed to cleanly restore the user's active session within React context, occasionally triggering null address errors during transaction execution. We resolved this by auditing the @mysten/dapp-kit-react provider hierarchy, standardizing our OAuth callback routes, and building an automated session-recovery hook that deterministically derives the ephemeral keypair and Sui address before enabling transaction actions.