{"uid":"cap_g8iSyXveRQHVDfEOU0pUp","slug":"delx-evm-calldata-shape-check-1122ee58","name":"Delx EVM Calldata Shape Check","description":"EVM Calldata Shape Check: EVM Calldata Shape Check checks 0x-prefixed calldata for even-length hexadecimal bytes from bounded caller-supplied values without an external provider. Call EVM Calldata Shape Check before signing, submitting, replacing, or accepting an EVM/Base transaction assembled from caller-owned data. Returns normalized transaction evidence, calculated budget or shape findings, and a fail-closed preflight status for EVM Calldata Shape Check as versioned deterministic JSON. Price…","url":"https://api.delx.ai/api/v1/x402/evm-calldata-shape-check","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"calldata":{"type":"string","maxLength":8192,"description":"Calldata supplied to EVM Calldata Shape Check; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"calldata":"0xa9059cbb0000000000000000000000001111111111111111111111111111111111111111","byte_count":36,"shape_valid":true},"schema":"delx/util-evm-calldata-shape-check/v1","status":"pass","evidence":{"retained":false,"input_sha256":"1048e8d74a53c6ea3249086735deac2cb24ee3dd131a3852df0439253301d8de","external_calls":0},"operation":"evm_preflight:evm_calldata_shape_check"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_9b_oUwbOCIl0KnJw8nL_l","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates the structural shape and byte count of EVM calldata hex strings without retaining or executing them.","exampleAgentPrompt":"Can you check whether this EVM calldata is structurally valid and tell me its byte count: 0xa9059cbb0000000000000000000000001111111111111111111111111111111111111111?","exampleUseCases":[{"title":"Preflight check before gas estimation","prompt":"Before I estimate gas for this transaction, can you verify the calldata shape is valid? Here's the hex: 0xa9059cbb000000000000000000000000abcdefabcdefabcdefabcdefabcdefabcdefabcd0000000000000000000000000000000000000000000000000de0b6b3a7640000"},{"title":"Debugging malformed contract call","prompt":"My ERC-20 transfer call keeps failing — can you check if this calldata is well-formed and give me the byte count so I can figure out what's wrong: 0xa9059cbb00000000000000000000000012345678"},{"title":"Validating agent-generated calldata","prompt":"I just had an agent encode a contract interaction — can you run a shape check on this calldata to confirm it's structurally correct before I broadcast it: 0x23b872dd000000000000000000000000aabbccdd11223344556677889900aabbccdd112233"}],"resultDescription":"Returns a JSON object with the original calldata, its byte count, a shape_valid boolean indicating structural correctness, an operation label, a schema identifier, a status field ('pass' or 'fail'), and an evidence block including a SHA256 hash of the input, confirmation that no data was retained, and a count of zero external calls made.","failureModes":["Invalid or non-hex calldata string returns shape_valid false","Calldata exceeding 8192 characters is rejected by schema validation","Malformed JSON request body causes a 400-level error","Empty calldata field may return an error or shape_valid false"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, privacy-preserving preflight check on EVM calldata shape before broadcasting a transaction or estimating gas. It is ideal for agent pipelines that generate or transform calldata and need a quick structural sanity check without executing anything on-chain or exposing calldata to stateful external services. Prefer it over full simulation tools when you only need byte-level shape validation, not execution traces or revert analysis.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T07:14:46.673Z","isFirstParty":false}