{"uid":"cap_sN4hoX7IhX8Xubq7L7WLq","slug":"delx-commerce-evm-signature-r-s-shape-check-feaf88f0","name":"Delx Commerce — EVM Signature R/S Shape Check","description":"Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.","url":"https://commerce.delx.ai/api/v1/x402/evm-signature-rs-shape-check?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"r":{"type":"string","maxLength":8192,"description":"R supplied to EVM Signature Rs Shape Check; used only for this bounded calculation and processed in memory without retention."},"s":{"type":"string","maxLength":8192,"description":"S supplied to EVM Signature Rs Shape Check; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"r":"0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","s":"0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb","shape_valid":true},"schema":"delx/util-evm-signature-rs-shape-check/v1","status":"pass","evidence":{"retained":false,"input_sha256":"a8860b963293e5de6a0dcbb51fc93e8b57c3290aa6e7a93a20c01c06569bf179","external_calls":0},"operation":"evm_preflight:evm_signature_rs_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_BV7vZYWjDQg-Q-Igp1Frg","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 whether the r and s components of an EVM ECDSA signature have valid cryptographic shape (within the secp256k1 curve bounds)","exampleAgentPrompt":"Check whether these EVM signature components have valid shape before I submit the transaction — r is 0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa and s is 0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb.","exampleUseCases":[{"title":"Pre-broadcast signature sanity check","prompt":"Before I broadcast this Ethereum transaction, can you verify that the signature r value 0x1a2b3c... and s value 0x4d5e6f... are actually valid secp256k1 scalars so we don't waste gas on a malformed signature?"},{"title":"Agent wallet signing pipeline guard","prompt":"My agent just produced a signature with r=0xdeadbeef... and s=0xcafe1234... — can you run a shape check on those to confirm they're within the valid ECDSA range before we proceed?"},{"title":"Debugging a rejected EVM transaction","prompt":"I submitted an Ethereum transaction and it got rejected — can you check whether the r and s components of my signature, 0xaaaa... and 0xbbbb..., have valid curve shape so I can figure out if the signature itself was the problem?"}],"resultDescription":"Returns a JSON object containing the original r and s values, a shape_valid boolean indicating whether both components are well-formed secp256k1 scalars, the operation name, status (pass/fail), and an evidence object with the SHA-256 hash of the input, a retained:false flag confirming no data storage, and a count of external calls made (always 0).","failureModes":["Malformed hex string for r or s returns a validation error","Values exceeding secp256k1 curve order return shape_valid: false","Input exceeding maxLength of 8192 characters rejected","Missing r or s field returns a schema validation error","Payment failure via x402 protocol prevents execution"],"whenToPreferThis":"Use this endpoint when you need a cheap, stateless, privacy-preserving preflight check on ECDSA signature r/s components before committing to an on-chain operation. Ideal for agent pipelines that need to guard against malformed signatures without storing any data. At $0.001 USDC per call with verifiable non-retention (SHA-256 evidence hash, no external calls), it's well-suited for high-frequency signature validation in automated workflows. Prefer this over full signature recovery endpoints when you only need shape validity, not signer identity.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T02:14:51.694Z","isFirstParty":false,"canonicalSlug":"delx-commerce-evm-signature-r-s-shape-check-feaf88f0"}