{"uid":"cap_N-9QVkm1UVv0ojiu8tckS","slug":"merchant-side-x402-pre-flight-payload-inspection-procedure-bc18e2ad","name":"Merchant-side x402 Pre-flight Payload Inspection Procedure","description":"Deterministic decision procedure for a merchant that wraps an API or MCP tool as an x402 service on Base, deciding whether an incoming paid request payload is safe to execute after settlement. Inputs: the request body, the declared content type, the proxy target if any, the paying address, the idempotency key if present. Procedure: (1) validate the payload against the declared schema before payment execution, (2) enforce size and depth limits, (3) check for injection and path-traversal vectors","url":"https://k2so-8080.on.ascii.dev/api/services/agent-infrastructure-decision-procedures-for-x40","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"Merchant-side x402 pre-flight payload inspection procedure paid response","$schema":"https://json-schema.org/draft/2020-12/schema","required":["ok","paid","service","provider","result"],"properties":{"ok":{"type":"boolean"},"paid":{"type":"boolean"},"result":{"type":"object","required":["ok","service"],"properties":{"ok":{"type":"boolean","description":"Handler success"},"brief":{"type":"string","description":"Decision procedure prose for agents"},"model":{"type":"string"},"topic":{"type":"string"},"service":{"type":"string","description":"Service slug"},"procedure":{"type":"string"},"generatedAt":{"type":"string","description":"ISO-8601 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":null,"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":"unknown","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_OBzW5I46o0lJV9vJ9CkQ6","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":"Returns a deterministic decision procedure for merchants to safely validate and inspect incoming paid API request payloads before executing them in an x402-gated service on Base.","exampleAgentPrompt":"I'm wrapping my API as an x402 service on Base — can you get me the merchant-side pre-flight payload inspection procedure so I know how to safely validate incoming paid request payloads for injection attacks, size limits, and schema conformance before I execute them?","exampleUseCases":[{"title":"Securing an x402-wrapped MCP tool","prompt":"I just wrapped one of my MCP tools as an x402 service and I want to know the correct procedure for inspecting incoming paid payloads before I execute them — specifically what injection, path traversal, and size checks I should enforce."},{"title":"Validating paying-address requests pre-settlement","prompt":"My x402 merchant endpoint is receiving requests from unfamiliar paying addresses on Base — what's the decision procedure for checking whether a request body is safe to run after the payment settles?"},{"title":"Enforcing schema and depth limits on paid API calls","prompt":"Can you fetch the merchant-side x402 pre-flight procedure for validating that incoming request bodies conform to my declared schema and stay within safe size and depth limits before I process them?"}],"resultDescription":"A structured decision procedure brief for the merchant, including a prose description of the validation steps, an ok/success flag, the service slug, generation source (llm, reasoning, or deterministic), an ISO-8601 timestamp, and optional model/topic metadata — all indicating whether the procedure was successfully retrieved and what logic to apply.","failureModes":["Invalid or missing HTTP method enum value returns a schema validation error","Non-GET/HEAD/DELETE method not supported by this endpoint","Malformed query parameters (e.g. meta not '0' or '1') may return an error or default behavior","Service unavailability on the provider host returns a network error with no procedure","Payment not completed results in a 402 response without the decision procedure content"],"whenToPreferThis":"Choose this endpoint when you are building or operating an x402 merchant service on Base and need authoritative, structured guidance on pre-execution payload inspection — particularly for injection defense, schema enforcement, size/depth limiting, and path-traversal prevention. Prefer this over generic security checklists when you need x402-specific, agent-readable procedure briefs that can be directly consumed by an autonomous merchant agent.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:49:13.613Z","isFirstParty":false}