{"uid":"cap_4q9Fzanxy5IP99oG0PiIA","slug":"base-chain-call-simulator-risk-analyzer-5f048f0c","name":"Base Chain Call Simulator & Risk Analyzer","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/api/chain/call?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_EtdTB9P7oR19if8d0kW5k","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 and risk-analyzes one or more Ethereum/Base smart contract calls, returning gas estimates, transfer breakdowns, balance changes, and a SAFE/UNSAFE verdict before broadcasting.","exampleAgentPrompt":"Before I send it, can you simulate this Base transaction — from 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 calling 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 with calldata 0xa9059cbb... — and tell me if it's safe, how much gas it'll use, and what token transfers will happen?","exampleUseCases":[{"title":"Safe-send check for USDC transfer","prompt":"I'm about to send 50 USDC from my wallet 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 to 0xa587d73489f8f09d1975f1ddbb1c61c93e8fa9d7 on Base — simulate it and tell me if it's safe, what the gas cost will be in USD, and whether any unexpected approvals are triggered."},{"title":"DeFi multicall sequence dry-run","prompt":"Dry-run these three chained calls on Base for me — approve, swap, and deposit — encoded as a calls array, sender is 0xe4be4d0bd82d8e68203deff81f79ede0529f2617. Tell me if all three succeed, the total gas, and how my token balances change at each step."},{"title":"Unknown calldata decode and risk check","prompt":"Someone sent me this calldata to sign: 0x095ea7b3000000000000000000000000[redacted]ffffffff — can you simulate what it does on Base from my address 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 and flag if it grants any dangerous approvals?"}],"resultDescription":"Returns a JSON object with: overall success boolean, SAFE_TO_SEND/UNSAFE verdict, decoded function name, gas used and fee in ETH/USD, list of token transfers with amounts and symbols, per-address balance changes, any detected approvals, revert reason if failed, current block number, and suggested next endpoints.","failureModes":["Invalid address format returns schema validation error","Reverted simulation returns success:false with revert_reason populated","Malformed calldata returns decode error","Call array exceeding 5 items rejected","Payment (x402 USDC) failure blocks the call","Network congestion may cause stale block data"],"whenToPreferThis":"Use this endpoint when an AI agent needs to pre-flight a Base chain transaction before broadcasting — especially to check safety, decode unknown calldata, preview balance changes, or detect malicious approvals. Prefer over generic gas estimators when you need decoded semantics (function name, token transfers, approval detection) rather than just a gas number. Ideal for onchain agents that must autonomously validate transactions before signing.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:41:53.637Z","isFirstParty":false,"canonicalSlug":"base-chain-call-simulator-risk-analyzer-5f048f0c"}