Arbitrum Open House London 2026
Veto ✋
Your AI tried. Veto said no.
WASM-powered trade interception on Robinhood Chain.
Solidity + Rust/Stylus Robinhood Chain 90% Gas Savings
142K gas → ~14K gas
WASM coprocessor
The AI Agent Problem
$1.7B
Lost to DeFi exploits in 2024 — and AI agents are making it worse by optimizing for return, not safety.
The Problem

AI Agents
Can't Say No

A DeFi yield optimizer spots a 10× APY pool. It doesn't check historical volatility. It doesn't compute variance. It just executes — and your ETH is gone.

NO MATH GUARDRAILS
Smart contract wallets control who can call, not what's sane to call. Access control ≠ risk control.
SOLIDITY IS TOO EXPENSIVE
Calculating variance over 100 data points in Solidity costs 211,246 gas. At scale, on-chain math is uneconomical.
AI DOESN'T UNDERSTAND RISK
LLMs optimize for yield metrics, not portfolio safety. They hallucinate confidence in volatile positions.
The Solution

Rust Does
The Math

Veto uses Arbitrum Stylus to run a Rust-compiled WASM coprocessor on-chain. It computes asset variance in ~14K gas and physically reverts dangerous trades.

~14K
WASM gas
142K
Solidity gas
90%
saved
localhost:3000
Veto Dashboard
How It Works
AI Agent Python · web3.py • Fetches 100 prices • Formats uint256[] calldata • Signs & submits tx VetoVault.sol EVM · Solidity • Holds ETH vault funds • Owner access control • Delegates math → Stylus RiskEngine.rs WASM · Arbitrum Stylus • Computes variance (U256) • no_std · no floats • Reverts if > threshold trade() check() EXECUTE REVERT variance > threshold? Stylus: ~14K gas vs Solidity: 142K gas
Live Demo
1 Price Chart
2 Agent Terminal
3 Intercept Card
4 Event Log
1
Price feed — 100 real candles from CoinGecko
2
Agent executes — Python submits trade tx
3
Veto intercepts — Stylus reverts with custom error
4
On-chain proof — Full event log on block explorer
Key Capabilities

Not a Suggestion.
A Physical Block.

Every feature is designed to make the REVERT happen at the EVM level — no off-chain oracles, no governance votes, no delay.

WASM Variance Engine
U256 integer math, no_std, no floats — 90% cheaper than Solidity
Custom Error Reverts
VolatilityExceedsThreshold(computed, limit) — typed, debuggable
Hybrid EVM/WASM
Solidity custody + Rust math — each contract does what it's best at
SOC Dashboard
Cyberpunk control panel — real-time trade monitoring and agent terminal
Why Now

Three Forces
Converging

Stylus shipped. AI agents are trading. Robinhood Chain launched. The infrastructure for on-chain risk computation didn't exist 6 months ago.

Stylus is production-ready
Rust/WASM contracts on Arbitrum — 10× cheaper compute for statistical functions
AI agents are unguarded
ERC-4337 wallets have no execution physics — Veto is the first risk layer
Robinhood Chain = retail
Millions of retail users will delegate to AI — they need protection, not complexity
Shipped Solo

Built in
14 Days

One developer. Two smart contracts. Three languages. Full-stack from Rust variance math to cyberpunk dashboard.

23
Passing Tests
90%
Gas Saved
3
Languages
1
Developer
The Ask

Veto ✋

"Solidity holds the money. Rust does the math."

$40K
Overall — Robinhood Chain Track
$7K
Best Agentic Project
$30K
Grants — Milestone-based
QR Code
github.com/edycutjong/veto
@edycutjong
"Your AI tried. Veto said no."
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