{"uid":"cap_nyaPgDA9tS8zmkeFTsRnh","slug":"agent-kiosk-evm-transaction-simulator-pre-flight-safety-checker-90142766","name":"Agent Kiosk EVM Transaction Simulator & Pre-flight Safety Checker","description":"Pre-flight EVM Transaction Simulator, Gas Estimator, Revert Reason Decoder, ERC-20 Allowance Checker & EIP-1967 Proxy Detector across Base, Ethereum, Arbitrum, Optimism, and Polygon.","url":"https://agent-kiosk.vercel.app/v1/tx-simulate?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"to":{"type":"string","description":"0x target contract or recipient address"},"data":{"type":"string","description":"0x hex calldata to simulate via eth_call & eth_estimateGas"},"from":{"type":"string","description":"0x sender address"},"chain":{"enum":["base","ethereum","arbitrum","optimism","polygon"],"type":"string","description":"Target EVM network (default: base)"},"token":{"type":"string","description":"Optional 0x ERC-20 token address to check allowance"},"value":{"type":"string","description":"Optional native ETH value in wei or 0x hex"},"spender":{"type":"string","description":"Optional 0x spender address to check ERC-20 allowance"},"tx_hash":{"type":"string","description":"Optional 0x transaction hash to fetch receipt"}}},"responseSchema":{"type":"json","example":{"chain":"base","verdict":"SAFE_TO_BROADCAST","chain_id":8453,"simulation":{"will_revert":false,"estimated_gas":26410,"gas_price_gwei":0.0061,"estimated_fee_usd":0.0004},"target_contract":{"address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","is_contract":true,"is_eip1967_proxy":true}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_PFS-CYCVAnHPj2cGpk2bM","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Simulates EVM transactions before broadcast, estimating gas, decoding revert reasons, checking ERC-20 allowances, and detecting EIP-1967 proxies across Base, Ethereum, Arbitrum, Optimism, and Polygon.","exampleAgentPrompt":"Before I send this transaction, simulate it on Base for me — the contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, calldata is 0xa9059cbb000000000000000000000000abc...0000000000000000000000000000000000000000000000000de0b6b3a7640000, and tell me if it will revert, how much gas it'll use, and the estimated fee in USD.","exampleUseCases":[{"title":"Pre-flight DeFi swap safety check","prompt":"I'm about to call a Uniswap contract on Ethereum — can you simulate this transaction first and tell me if it'll revert, and what the gas cost will be in USD? From address is 0xMyWallet, to is 0xUniswapRouter, and calldata is 0xswapExactTokensForTokens..."},{"title":"ERC-20 allowance verification before approval","prompt":"Check whether 0xSpenderContract already has enough allowance to spend my USDC tokens on Arbitrum — token address is 0xaf88d065e77c8cC2239327C5EDb3A432268e5831, my wallet is 0xMyAddress, and the spender is 0xSpenderContract."},{"title":"Revert reason decoding for failed transaction","prompt":"My transaction 0xabc123...def456 failed on Optimism — can you fetch the receipt and decode why it reverted so I know what went wrong?"}],"resultDescription":"Returns a JSON object with a safety verdict (e.g. SAFE_TO_BROADCAST), simulation results (will_revert boolean, estimated gas, gas price in gwei, estimated fee in USD), target contract metadata (address, is_contract, is_eip1967_proxy), and chain ID. Optionally includes ERC-20 allowance data if token and spender are provided.","failureModes":["Invalid or malformed contract address returns an error","Unsupported chain enum value rejected","Missing required 'to' or 'data' fields causes 400 error","Transaction simulation may fail if RPC node is congested or unavailable","EIP-1967 proxy detection may return false negative for non-standard proxy patterns","Payment failure (x402) if USDC balance is insufficient"],"whenToPreferThis":"Use this endpoint when you need to pre-flight check any EVM transaction before broadcasting it, especially for DeFi interactions where a revert would waste gas. Prefer this over raw RPC calls when you need a combined verdict covering gas estimation, revert detection, proxy detection, and allowance checking in a single call across multiple chains.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-19T12:35:20.616Z","isFirstParty":false,"canonicalSlug":"agent-kiosk-evm-transaction-simulator-pre-flight-safety-checker-90142766"}