{"uid":"cap_NJbuwkQI1lx6te7pXYim8","slug":"facilitator-preemption-attack-exposure-audit-for-agent-payment-rails-c9647623","name":"Facilitator Preemption Attack Exposure Audit for Agent Payment Rails","description":"Audit procedure for whether an agent's payment facilitator can front-run, preempt, or reorder agent transactions on x402 rails. Inputs: facilitator identity, settlement path, mempool visibility, transaction submission order, and any relay/replace capabilities. Output: exposure verdict per attack class (front-run, preempt, reorder, suppress), evidence checklist for each, a pay/no-pay rule for that facilitator, and mitigations (private submission, direct-to-settler path, receipt cross-check). For","url":"https://k2so.wrong.systems/api/services/facilitator-preemption-attack-exposure-audit-for?utm_source=zero.xyz","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","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"Facilitator Preemption Attack Exposure Audit for Agent Payment Rails paid 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timestamp"},"generationSource":{"enum":["llm","reasoning","deterministic"],"type":"string"}}},"payment":{"type":"object","properties":{"code":{"type":"string"},"payer":{"type":"string"},"detail":{"type":"string"},"selfPay":{"type":"boolean"},"transaction":{"type":"string"}}},"service":{"type":"string"},"provider":{"type":"string","const":"K-2SO"}}}}}}},"responseSchema":{"type":"json","example":{"ok":true,"paid":true,"result":{"ok":true,"brief":"plain prose decision procedure (120+ words)","model":"deepseek/deepseek-v4-flash-0731","topic":"string topic","service":"facilitator-preemption-attack-exposure-audit-for","procedure":"same as brief","generatedAt":"2026-01-01T00:00:00.000Z","generationSource":"deterministic"},"service":"facilitator-preemption-attack-exposure-audit-for","provider":"K-2SO"}},"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":"down","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_z-Zsoe4YDE776dEk7sSti","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":"Audits whether an x402 payment facilitator can front-run, preempt, reorder, or suppress an agent's transactions, returning an exposure verdict and mitigations per attack class.","exampleAgentPrompt":"Run a preemption attack exposure audit on my x402 facilitator — check whether it can front-run, reorder, or suppress my agent's transactions given its current settlement path and mempool visibility, and tell me whether I should keep paying through it or switch.","exampleUseCases":[{"title":"Vetting a new x402 facilitator before deployment","prompt":"Before I go live with this facilitator on x402 rails, can you audit it for front-running and transaction suppression risk and give me a pay/no-pay verdict with an evidence checklist?"},{"title":"Investigating suspected transaction reordering","prompt":"My agent's payments seem to be arriving out of order — can you check whether my current facilitator has mempool visibility and the ability to reorder or preempt my transactions, and suggest mitigations if so?"},{"title":"Hardening agent payment pipeline against preemption","prompt":"I want to harden my autonomous agent's payment pipeline against facilitator preemption attacks — audit the settlement path and relay capabilities of my facilitator and tell me what private submission or direct-to-settler options I should adopt."}],"resultDescription":"Returns a JSON object containing an exposure verdict for each attack class (front-run, preempt, reorder, suppress), an evidence checklist for each class, a pay/no-pay rule for the facilitator, and concrete mitigations such as private submission channels, direct-to-settler routing, and receipt cross-checking. The response includes a prose decision procedure (120+ words) and metadata including generation source and timestamp.","failureModes":["Insufficient input about facilitator identity or settlement path may yield an inconclusive verdict","Mempool visibility data not provided may result in incomplete front-run exposure assessment","If the facilitator is unknown or unlisted, the evidence checklist may be sparse","LLM-generated procedures may reflect training cutoff rather than latest protocol changes","Network or payment failure returns no verdict"],"whenToPreferThis":"Choose this endpoint when an AI agent needs to evaluate a specific x402 payment facilitator's trustworthiness before routing funds, especially when operating unattended and unable to manually verify transaction ordering integrity. Prefer this over generic blockchain security audits when the concern is specifically facilitator-level MEV-style attacks on x402 rails.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T17:28:42.035Z","isFirstParty":false,"canonicalSlug":"facilitator-preemption-attack-exposure-audit-for-agent-payment-rails-c9647623"}