{"uid":"cap_k9tHUguwhQYy_8TY2S12W","slug":"merchant-side-x402-pre-flight-payload-inspection-procedure-f9f690ce","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.wrong.systems/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":{"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":"agent-infrastructure-decision-procedures-for-x40","procedure":"same as brief","generatedAt":"2026-01-01T00:00:00.000Z","generationSource":"deterministic"},"service":"agent-infrastructure-decision-procedures-for-x40","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":"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_3WvNjXP5To76rLp5Iubyv","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 brief for x402 merchants to safely validate, size-check, and injection-scan incoming paid API request payloads before execution on Base.","exampleAgentPrompt":"Give me the x402 merchant pre-flight inspection procedure for validating an incoming paid HTTP GET request body — I need to know the schema validation, size limits, and injection-check steps to run before executing and settling payment on Base.","exampleUseCases":[{"title":"Securing an x402-wrapped AI tool endpoint","prompt":"I'm wrapping a code-execution MCP tool as an x402 service on Base — what pre-flight checks should I run on the incoming request payload before I execute anything and settle the payment?"},{"title":"Preventing injection in a paid proxy service","prompt":"My x402 merchant proxy forwards paid requests to a backend REST API. Walk me through the injection and path-traversal checks I need to enforce on each incoming request body before I let it through."},{"title":"Enforcing payload size limits on a paid API","prompt":"I need to protect my x402-gated API from oversized or deeply nested payloads — what are the size and depth limits I should enforce, and at what point in the payment flow should I apply them?"}],"resultDescription":"A structured response containing a prose decision procedure brief (the 'brief' field) with step-by-step guidance for validating x402 payloads, along with the service slug, topic, model, generation source (llm/reasoning/deterministic), and an ISO-8601 timestamp. The 'ok' boolean indicates handler success.","failureModes":["Invalid or missing required 'input' object returns a schema validation error","Unsupported HTTP method (non-GET/HEAD/DELETE) rejected by enum constraint","Service unavailable on k2so.wrong.systems returns network error","Payment not settled before request execution results in 402 response requiring x402 payment flow","Malformed query parameters return validation errors"],"whenToPreferThis":"Choose this endpoint when building or auditing an x402 merchant service on Base that needs to safely gate execution of paid API or MCP tool calls — specifically when you need a concrete, authoritative decision procedure for payload validation, injection prevention, and size enforcement before payment settlement. It is purpose-built for the x402 protocol context and covers Base-specific merchant security concerns that generic API security guides do not address.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:41:23.181Z","isFirstParty":false}