{"uid":"cap_2faeU0w-Tu5mYFQv1cbBd","slug":"x402-challenge-version-check-3398636b","name":"X402 Challenge Version Check","description":"X402 Challenge Version Check: X402 Challenge Version Check compares challenge protocol version with supported versions from bounded caller-supplied values without an external provider. Call X402 Challenge Version Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Challenge Version Check as versi…","url":"https://api.delx.ai/api/v1/x402/x402-challenge-version-check","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"version":{"type":"integer","description":"Version supplied to X402 Challenge Version Check; used only for this bounded calculation and processed in memory without retention."},"supported_versions":{"type":"array","items":{"type":"integer"},"maxItems":256,"description":"Supported Versions supplied to X402 Challenge Version Check; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"version":2,"supported":true,"supported_versions":[1,2]},"schema":"delx/util-x402-challenge-version-check/v1","status":"pass","evidence":{"retained":false,"input_sha256":"19a97d5b88dfc156ec9b3f1ff4cfb324dd9d18bb96d5ff480a3478193db0eeab","external_calls":0},"operation":"delivery_contract:x402_challenge_version_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_d2Qiv7GnqTGdY10Ymlfnw","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 a given x402 challenge protocol version is supported by comparing it against a caller-supplied list of accepted versions, returning acceptance status and mismatch reasons.","exampleAgentPrompt":"Before I accept this x402 payment challenge, check if version 3 is compatible with our supported versions [1, 2, 3, 5] and tell me whether to accept or reject it.","exampleUseCases":[{"title":"Pre-payment version compatibility gate","prompt":"I'm about to pay for an x402 service that sent a challenge with version 4 — check if that's compatible with our supported versions [1, 2, 4] before I authorize anything."},{"title":"Agent delivery challenge screening","prompt":"We're receiving an agent delivery result packaged with an x402 challenge version of 2. Our system supports versions [2, 3]. Validate whether we should accept or reject it and give me the mismatch reasons if any."},{"title":"Multi-version rollout compatibility audit","prompt":"I'm rolling out a new x402 integration and need to know if challenge version 7 will be accepted by our current stack that supports versions [5, 6, 7, 8]. Run the version check and show me the normalized evidence."}],"resultDescription":"Returns an explicit acceptance or rejection status for the given x402 challenge version, along with contract-specific check results, normalized evidence, and detailed mismatch reasons explaining why the version was or was not accepted.","failureModes":["Version integer outside expected range returns rejection with mismatch details","supported_versions array exceeds 256-item limit returns validation error","Missing required version or supported_versions fields returns 400 bad request","Empty supported_versions list always results in rejection","Non-integer version values cause schema validation failure"],"whenToPreferThis":"Use this endpoint when an agent or service needs a deterministic, auditable check of whether an incoming x402 challenge version is permissible before proceeding with payment or accepting a delivery. Prefer this over manual in-code comparisons when you need normalized evidence and explicit rejection reasons logged for audit trails, or when building payment-gating workflows where version mismatches must be surfaced clearly.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T19:02:50.531Z","isFirstParty":false}