{"uid":"cap_BlavZQ9wIBd3SeApxOc-3","slug":"api-production-2800-up-railway-app-069c4485","name":"AgentSpendGuard Transaction Explain & Calldata Risk API","description":"Transaction explain and calldata risk API by AgentSpendGuard for AI wallet agents before signing EVM transactions. Search keywords: transaction explain, calldata explain, approval risk detector, unlimited allowance, EVM signing guardrail, wallet agent safety, agent spend guard. Returns strict JSON intent, risk score, reason codes, and recommended action.","url":"https://api-production-2800.up.railway.app/v1/tx-explain","method":"POST","headers":{},"bodySchema":{"type":"object","required":["data"],"properties":{"to":{"type":"string","pattern":"^0x[a-fA-F0-9]{40}$"},"data":{"type":"string","pattern":"^0x[a-fA-F0-9]*$"},"from":{"type":"string","pattern":"^0x[a-fA-F0-9]{40}$"},"chainId":{"enum":[1,8453,84532,10,42161,137],"type":"integer","default":8453},"valueWei":{"type":"string","default":"0","pattern":"^\\d+$"},"knownSpenders":{"type":"array","items":{"type":"string","pattern":"^0x[a-fA-F0-9]{40}$"}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.010000","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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":"$0.010000/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_JyNpCUGn9RDqStlfFvmJu","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Analyzes EVM transaction calldata before signing, returning a human-readable intent explanation, risk score, reason codes, and recommended action for AI wallet agents.","exampleAgentPrompt":"Before I sign this transaction, explain what it does and tell me if it's safe — the calldata is 0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff on contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Base mainnet.","exampleUseCases":[{"title":"Detect unlimited token approvals before signing","prompt":"I'm about to approve a token to a DeFi protocol but I'm worried about unlimited allowances — can you check this transaction calldata and tell me if it's asking for unlimited spending permissions? The contract is 0x68b3465833fb72B5A828cCEd3882857713B5aA28 and the calldata is 0x095ea7b3000000000000000000000000e592427a0aece92de3edee1f18e0157c05861564ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff."},{"title":"Identify phishing and malicious contract interactions","prompt":"This contract address 0x1234567890123456789012345678901234567890 is trying to get me to call some function — before I sign anything, analyze this calldata 0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045 and tell me if it looks like a phishing scam or if there are any red flags I should know about."},{"title":"Understand complex DeFi transaction intent and risk","prompt":"I'm about to execute a swap on a DEX but the calldata looks complicated — explain what this transaction actually does 0x414bf3890000000000000000000000001111111254fb6c44bac0bed2854e76f90643097d and give me a risk assessment before I sign on mainnet."}],"resultDescription":"A strict JSON object containing a plain-language intent description of what the transaction does, a numeric risk score (0-100), one or more reason codes (e.g. UNLIMITED_ALLOWANCE, UNKNOWN_CONTRACT, PHISHING_PATTERN), and a recommended action (allow, caution, or block) for the agent to act on before signing.","failureModes":["Invalid or unparseable calldata returns an error response","Unsupported chain ID returns a 400 or unknown-chain error","Missing required fields in POST body returns 422 validation error","Payment not included or invalid x402 payment header returns 402 Payment Required","Contract not found on specified chain returns partial analysis with low confidence","Rate limiting or service unavailability returns 503"],"whenToPreferThis":"Use this endpoint when an AI wallet agent or autonomous DeFi agent needs a pre-signing safety check on raw EVM calldata, especially for detecting unlimited token approvals, phishing contract interactions, or unexpected fund transfers. Prefer this over generic contract explorers when you need a structured JSON verdict with risk scores and reason codes that an agent can act on programmatically.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:32:09.074Z","isFirstParty":false}