{"uid":"cap_iGoxv8RIqD1hQlh5sM1Kx","slug":"evm-calldata-encoder-with-risk-flags-143f294e","name":"EVM Calldata Encoder with Risk Flags","description":"Build EVM calldata from a named function and human arguments, with deterministic risk flags; never signs or broadcasts","url":"https://evm-canon-base.onrender.com/encode","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["args"],"properties":{"args":{"type":"object","description":"arguments keyed by parameter name"},"chain":{"description":"chain name, alias or numeric chainId"},"token":{"type":"string","description":"symbol or contract address"},"value":{"type":"string","description":"native value in wei"},"function":{"type":"string","description":"name or full signature (generic route only)"}}},"type":{"type":"string","const":"http"},"method":{"enum":["POST","PUT","PATCH"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/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_1UcCNtgv31t6nx6ATFNap","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Encodes EVM calldata from a named function signature and human-readable arguments, returning deterministic risk flags without signing or broadcasting","exampleAgentPrompt":"Can you encode the calldata for calling the `transfer(address,uint256)` function with recipient `0xAbCd...1234` and amount `1000000000000000000` (1 ETH in wei), and tell me if there are any risk flags I should know about before I sign anything?","exampleUseCases":[{"title":"Safe DeFi swap calldata preparation","prompt":"Build the calldata for calling `swapExactTokensForTokens(uint256,uint256,address[],address,uint256)` with amountIn 500000000, amountOutMin 490000000, path [0xTokenA, 0xTokenB], recipient 0xMyWallet, and deadline 1999999999 — and flag any risks before I sign."},{"title":"ERC-20 transfer calldata for review","prompt":"Encode the calldata for an ERC-20 `transfer(address,uint256)` call sending 250 USDC (250000000 in raw units) to 0xRecipient1234 and show me the risk flags so I can review it before broadcasting."},{"title":"Contract interaction audit before execution","prompt":"I want to call `setApprovalForAll(address,bool)` on an NFT contract with operator 0xOperatorAddress and approved true — can you encode the calldata and flag any risks associated with this function call?"}],"resultDescription":"Returns ABI-encoded calldata as a hex string ready to be used as transaction data, along with deterministic risk flags (e.g. unlimited allowance, high-risk function detected) based on the function and arguments provided. No signing or broadcasting occurs.","failureModes":["Invalid function signature or ABI mismatch returns a 400 error","Malformed or out-of-range argument values cause encoding failure","Unknown function name with no ABI provided results in an error","Payment not included or insufficient USDC causes a 402 response","Argument count mismatch with function signature returns descriptive error"],"whenToPreferThis":"Use this endpoint when you need to construct EVM transaction calldata from human-readable function names and arguments before signing, especially when you want deterministic risk flags evaluated upfront. Prefer this over raw ABI encoding libraries when you need an auditable, server-side encoding step with built-in safety checks, or when orchestrating agent workflows that must validate transaction intent before committing.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:42:59.655Z","isFirstParty":false}