{"uid":"cap_y0ZEEKsXVQJKjpYFpMIo4","slug":"txsim-decoder-cae0ad63","name":"TxSim Decoder","description":"Decode raw EVM calldata into a named function, signature and arguments, plus security risk flags (unlimited token approval, setApprovalForAll, ownership transfer, unknown selector, native value transfer). Keyless, deterministic, no simulation - the cheap way for an agent to understand and risk-screen a piece of calldata before signing.","url":"https://simulate.cyberwarex.com/decode","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","required":["data"],"properties":{"to":{"type":"string","pattern":"^0x[a-fA-F0-9]{40}$","description":"Target address (optional, for context only)."},"data":{"type":"string","pattern":"^0x[a-fA-F0-9]*$","description":"Transaction calldata (hex, 4-byte selector + ABI args)."}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"risk":{"type":"object","description":"level (none|caution|danger) + flags."},"decoded":{"type":"object","description":"function, signature, args."},"disclaimer":{"type":"string"}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_k2XJdHtxx_v4r9v5lodjW","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes raw EVM calldata into a named function, signature, and arguments, and flags security risks like unlimited token approvals or ownership transfers — without simulation or an API key.","exampleAgentPrompt":"Before I sign this transaction, can you decode the calldata 0x095ea7b3000000000000000000000000deadbeef000000000000000000000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff and tell me what function it's calling and whether it looks risky?","exampleUseCases":[{"title":"Unlimited token approval detection","prompt":"I'm about to sign a transaction with calldata 0x095ea7b3000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff — decode it and warn me if it's an unlimited token approval."},{"title":"setApprovalForAll safety check","prompt":"My wallet is asking me to sign this calldata: 0xa22cb465000000000000000000000000abcdef1234567890abcdef1234567890abcdef120000000000000000000000000000000000000000000000000000000000000001 — what function is this calling and is it dangerous?"},{"title":"Unknown selector risk screening","prompt":"I received a transaction with calldata 0xdeadbeef00000000000000000000000000000000000000000000000000000000cafebabe — can you decode it and tell me if the selector is recognized and what the risk level is?"}],"resultDescription":"Returns a decoded object with the function name, full signature, and parsed arguments, plus a risk assessment object containing a severity level (none, caution, or danger) and specific security flags such as unlimited token approval, setApprovalForAll, ownership transfer, unknown selector, or native value transfer. Also includes a disclaimer string.","failureModes":["Calldata too short or malformed hex returns a parse error","Unknown 4-byte selector cannot be resolved to a function name, flagged as unknown selector risk","Missing required 'data' query parameter returns a validation error","Calldata with no arguments beyond the selector may return empty args array","Non-EVM or non-hex input will fail pattern validation"],"whenToPreferThis":"Choose this endpoint when an agent needs a fast, keyless, no-simulation way to decode and risk-screen raw EVM calldata before presenting a transaction to a user for signing. Ideal for wallet agents, DeFi automation bots, and security screening pipelines where cost and latency matter and full simulation is overkill. Prefer over full EVM simulators when you only need function identity and static risk flags, not execution traces or state diffs.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:40:07.411Z","isFirstParty":false}