{"uid":"cap_IqrSfCiQ8l01Iy6hoXBQX","slug":"agenttools-evm-transaction-explainer-b9b0cf17","name":"AgentTools EVM Transaction Explainer","description":"Explain what an EVM transaction would actually do: decodes the calldata (ERC-20 transfers/approvals via known ABIs, unknown selectors via the 4byte directory) and simulates the call against live chain state to report the outcome — including unlimited-approval warnings — without sending anything. Use this when an agent needs to decode and simulate a transaction — before signing it.","url":"https://agentstoolshub.com/api/v1/crypto/tx-explain?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","required":["to","data"],"properties":{"to":{"type":"string","description":"To address"},"data":{"type":"string","description":"Calldata (0x hex)"},"chain":{"enum":["base","ethereum"],"type":"string","description":"Chain"},"value":{"type":"string","description":"Value (wei, optional)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.015","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":"$0.015/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.015","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.015","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_trdDvTT_TidSrPpOIYCL_","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.015","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes EVM transaction calldata and simulates it against live chain state to explain what it would do — including unlimited-approval warnings — without broadcasting it.","exampleAgentPrompt":"Before I sign this transaction, can you decode and simulate the calldata 0xa9059cbb000000000000000000000000abcdef1234567890abcdef1234567890abcdef12000000000000000000000000000000000000000000000000de0b6b3a7640000 sent to 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on base, and tell me if there are any unlimited-approval risks?","exampleUseCases":[{"title":"Safe signing check before DeFi approval","prompt":"I'm about to sign this approval transaction on Ethereum — calldata is 0x095ea7b3ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff to 0xdAC17F958D2ee523a2206206994597C13D831ec7 — can you simulate it and warn me if it's an unlimited approval?"},{"title":"Decode unknown contract interaction","prompt":"Can you explain what this calldata does: 0x38ed1739 to contract 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D on ethereum? I don't recognize the function and want to know what it would actually do before I send it."},{"title":"Preview token transfer outcome","prompt":"Simulate this ERC-20 transfer on Base for me — to address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, calldata 0xa9059cbb000000000000000000000000deadbeefdeadbeefdeadbeefdeadbeefdeadbeef0000000000000000000000000000000000000000000000056bc75e2d63100000 — will it go through and how many tokens are being sent?"}],"resultDescription":"Returns a human-readable explanation of the transaction: the decoded function name and parameters (e.g. 'transfer 100 USDC to 0xABC...'), a simulation result indicating whether the call would succeed or revert against current chain state, token amounts and recipients for ERC-20 transfers, and a prominent warning if the transaction grants an unlimited (max uint256) token approval.","failureModes":["Unknown calldata selector not found in 4byte directory — returns raw hex with partial decode","Invalid 'to' address format — returns 400 error","Simulation reverts on-chain — returns revert reason if available, or generic revert","Unsupported chain value — returns validation error","Malformed hex calldata — returns parse error","Network timeout fetching live chain state — returns 503 or timeout error"],"whenToPreferThis":"Use this endpoint when an AI agent or wallet interface needs to explain an EVM transaction to a user before they sign it — especially for DeFi interactions, token approvals, or any calldata that may be opaque. Prefer this over generic ABI decoders when you also need live simulation (will it revert?) and security warnings (unlimited approvals). Ideal for agent-driven signing flows on Base or Ethereum where user safety and informed consent matter.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T12:49:56.799Z","isFirstParty":false,"canonicalSlug":"agenttools-evm-transaction-explainer-b9b0cf17"}