VETO

Inspiration

The Fatal Flaw of Modern Money: Finality without Consent.

Modern financial systems have a structural tragedy: Banks are too slow to intervene, and Blockchains are too fast to reverse. Once a user clicks Send, the system assumes the decision was rational—even when it was the result of psychological manipulation. Authorized Push Payment (APP) fraud is now a multi-billion dollar crisis because scammers hack the human, not the code.

Inspired by the Octopus’s adaptability and intelligence, we realized that programmable money doesn’t have to be instant—it can be intelligent. We built VETO to introduce "Intelligent Friction," giving users a power they’ve never had: The power to stop a mistake after it happens.

What it does

VETO is a safety layer and "Circuit Breaker" for programmable finance. It separates Authorization from Settlement to break the urgency that scammers rely on.

• AI-Driven Risk Detection: Instead of just blacklisting addresses, VETO uses AI to detect "Scam Signatures" like the Penny Drop pattern, hyper-urgent behavior, and brand-new recipient addresses.
• The Smart Vault (Cooling-Off Period): When high risk is detected, funds are moved out of the user’s wallet into a Time-Locked Smart Vault. This avoids tipping off the scammer while keeping the funds secure.
• The Veto Power: During this safety window, the user has the absolute right to hit the Veto Button, instantly reversing the transaction and pulling their funds back from the vault.

How we built it

We built a production-grade full-stack prototype:

• Mobile Interface: Developed with React Native (Expo), focusing on "Calm Tech" UX to reduce user panic during high-stress moments.
• Web Dashboard: Built with Next.js 14 for transparent monitoring of the Smart Vault and transaction history.
• The Brain (AI Risk Engine): A Python/FastAPI backend using LangChain and Gemini 2.5 Flash. It provides real-time, explainable risk verdicts.
• The Muscle (Smart Contracts): Solidity contracts deployed on Ethereum (optimized for MNEE). The Vault logic ensures that "Code is Law," but "Code also allows for Correction."

Challenges we ran into

• Latency vs. Security: Running deep AI risk analysis in the milliseconds between a user clicking "Send" and the transaction broadcasting required heavy optimization of our FastAPI endpoints.
• On-Chain Logic: Simulating a "Probationary Transaction" without compromising the user experience of "instant" feel was a complex balance of state management between the frontend and the blockchain.
• Gas Efficiency: Routing funds through a middle-layer Vault increases gas. We addressed this by building efficient pre-transaction estimators to ensure users aren't blindsided by costs during an emergency.

Accomplishments that we're proud of

• The "Undo" Moment: Successfully seeing a transaction reverse and tokens return to the wallet after a simulated scam was our biggest "Eureka" moment.
• Explainable AI: Moving beyond "Black Box" models to an AI agent that can explain why it flagged a transaction (e.g., "Detected Penny Drop pattern").
• Holistic Protection: Creating a system that protects the most vulnerable users (like the elderly) without stripping away their financial autonomy.

What we learned

We learned that Trust is the ultimate utility. While the industry focuses on "Trustless" systems, the average user needs a system they can trust to protect them. We also gained deep insights into how psychological triggers (Urgency/Fear) can be mapped into deterministic data patterns for AI detection.

What's next for VETO

• VETO SDK: Building an API so any wallet or dApp can integrate our "Undo Button" logic.
• Guardian Network: Introducing social recovery where a trusted friend or family member can help "Veto" a high-value suspicious transaction.
• Cross-Chain Interoperability: Expanding the Smart Vault logic to other ecosystems (like NEAR or Solana) to protect the entire Web3 space.
• Institutional Partnerships: Collaborating with Neo-banks to bring this "Safety Layer" to traditional fiat transfers.

Built With

• ether.js
• expo.io
• fastapi
• gemini
• langchain
• nativewind
• next.js
• python
• react-native
• solidity