{"uid":"cap_ihrOp5cTRaBPQSHQMCjWW","slug":"base-chain-transaction-simulator-x402-41bb5cc0","name":"Base Chain Transaction Simulator (x402)","description":"Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.","url":"https://kr-x402-mvp.kgy5612.workers.dev/v1/crypto/simulate?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","properties":{"to":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","examples":["0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"],"description":"Target contract or recipient"},"data":{"type":"string","pattern":"^0x([0-9a-fA-F]{2})*$","description":"Calldata (default 0x)"},"from":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","examples":["0xe4be4d0bd82d8e68203deff81f79ede0529f2617"],"description":"Sender (signer) address"},"calls":{"type":"string","description":"URL-encoded JSON array of up to 5 {to,data,value_eth|value} run in order from the same sender"},"value_eth":{"type":"string","examples":["0.01"],"description":"ETH to send, decimal (default 0)"}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"from":"0xe4be4d0bd82d8e68203deff81f79ede0529f2617","next":["/crypto/base-gas","/crypto/tx-status?hash="],"block":53272234,"calls":[{"to":"0x833589fcd6edb6e08f4c7c32d4f71b54bda02913","index":0,"success":true,"function":"transfer(address,uint256)","gas_used":45047,"revert_reason":null}],"chain":"base","flags":[],"fee_eth":5e-7,"fee_usd":0.0019,"success":true,"summary":"1 call succeeds; sender sends 0.001 USDC","verdict":"SAFE_TO_SEND","approvals":[],"transfers":[{"to":"0xa587d73489f8f09d1975f1ddbb1c61c93e8fa9d7","from":"0xe4be4d0bd82d8e68203deff81f79ede0529f2617","token":"0x833589fcd6edb6e08f4c7c32d4f71b54bda02913","amount":0.001,"symbol":"USDC"}],"gas_used_total":45047,"sender_changes":{"USDC":-0.001},"balance_changes":{"0xa587d73489f8f09d1975f1ddbb1c61c93e8fa9d7":{"USDC":0.001},"0xe4be4d0bd82d8e68203deff81f79ede0529f2617":{"USDC":-0.001}}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_tCyUD8skIjXnbCMbC66av","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Simulates one or more Base chain transactions to preview gas costs, token transfers, balance changes, and safety verdict before execution","exampleAgentPrompt":"Before I send 0.001 USDC from 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 to 0xa587d73489f8f09d1975f1ddbb1c61c93e8fa9d7 on Base, simulate the transaction using the USDC contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 and tell me if it's safe, what gas it'll cost, and what balance changes will happen.","exampleUseCases":[{"title":"Pre-flight check for DeFi swap","prompt":"Simulate this swap calldata on Base before I execute it — sender is 0xe4be4d0bd82d8e68203deff81f79ede0529f2617, target contract is 0x2626664c2603336E57B271c5C0b26F421741e481, calldata is 0x04e45aaf..., and I want to know the gas cost in USD, whether it'll succeed, and what tokens move."},{"title":"Multicall safety review for trading bot","prompt":"My trading bot wants to run 3 sequential calls on Base from 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 — can you simulate them all at once and tell me the total gas, any reverts, and all token balance changes before it submits anything?"},{"title":"Revert diagnosis for failed contract call","prompt":"This transaction to 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base keeps failing — sender is 0xe4be4d0bd82d8e68203deff81f79ede0529f2617, calldata is 0xa9059cbb..., can you simulate it and tell me the revert reason?"}],"resultDescription":"Returns a JSON object with: overall success/failure verdict (SAFE_TO_SEND or REVERTED), per-call breakdown (function decoded, gas used, revert reason), total gas used, fee in ETH and USD, list of token transfers with amounts and symbols, balance changes per address, and suggested next endpoints. Block number and chain are also included.","failureModes":["Invalid address format returns 400 validation error","Malformed calldata hex returns parse error","Simulation of call that would revert returns success:false with revert_reason populated","Missing required 'to' param when not using multicall returns 400","x402 payment failure blocks access with 402 response","Network congestion on Base may cause simulation timeouts"],"whenToPreferThis":"Use this endpoint when you need to dry-run a Base chain transaction before committing it onchain — especially for AI trading agents that need safety verdicts, gas estimates, and token flow previews without risking funds. Prefer over on-chain submission when you want to detect reverts, decode function calls, or audit balance changes in advance. The pay-per-call x402 model (no API key) makes it ideal for autonomous agents.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:42:17.163Z","isFirstParty":false,"canonicalSlug":"base-chain-transaction-simulator-x402-41bb5cc0"}