{"uid":"cap_7xsf1wQEyDmDkUcvAd8ir","slug":"signgate-x402-agent-buyer-identity-preflight-9a8a9395","name":"SignGate x402 Agent Buyer Identity Preflight","description":"Machine-payable service intelligence for discovering, verifying, and monitoring identity, risk, authorization, execution-preflight, and evidence APIs before autonomous agents spend.","url":"https://base-agent-preflight.bytoken2023.workers.dev/v1/x402/agent/rpc-payment-guard","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["request_id","endpoint_url","chain","method","amount_usdc"],"properties":{"chain":{"type":"string","pattern":"^[A-Za-z0-9:_ -]{2,80}$","description":"Requested chain or CAIP-2 network label."},"method":{"type":"string","pattern":"^[A-Za-z0-9_.:-]{2,80}$","description":"RPC method, REST operation, or query action."},"pay_to":{"type":"string","pattern":"^0x[a-fA-F0-9]{40}$","description":"Payment recipient address."},"request_id":{"type":"string","pattern":"^[A-Za-z0-9._:-]{1,128}$","description":"Caller-defined idempotency key for this RPC purchase."},"amount_usdc":{"type":"string","pattern":"^[0-9]+(?:\\.[0-9]{1,6})?$","description":"Requested stablecoin payment amount."},"endpoint_url":{"type":"string","pattern":"^https?://","maxLength":2048,"description":"RPC, x402, REST, or indexed chain-data endpoint URL."},"max_single_usdc":{"type":"string","pattern":"^[0-9]+(?:\\.[0-9]{1,6})?$","description":"Maximum allowed amount for one RPC/data purchase."},"session_budget_usdc":{"type":"string","pattern":"^[0-9]+(?:\\.[0-9]{1,6})?$","description":"Remaining budget for this agent session."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"network":{"type":"string"},"product":{"type":"string"},"activity":{"type":"object"},"identity":{"type":"object"},"assessment":{"type":"object"},"provenance":{"type":"object"}}}}}}},"responseSchema":{"type":"json","example":{"network":"eip155:8453","product":"x402-rpc-payment-guard","assessment":{"flags":[],"risk_level":"low","risk_score":0}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","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":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Hh0oOFJqb38z1B_dbCT3S","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates whether an AI agent is authorized to make a specific x402 micropayment purchase by checking buyer identity, product category, price thresholds, and approval policy before the transaction occurs.","exampleAgentPrompt":"Before you pay for that x402 RPC endpoint at https://api.example.com/rpc using 0.05 USDC on eip155:8453, run a preflight check with request ID req-abc123 to make sure this purchase is authorized, the method is eth_call, and my session budget of 5.00 USDC and single-purchase cap of 0.10 USDC aren't exceeded.","exampleUseCases":[{"title":"Budget cap enforcement for agent fleet","prompt":"Before my autonomous agent pays 0.08 USDC for that dataset API on Base, check whether it's within the session budget of 2.00 USDC and the single-purchase limit of 0.10 USDC — use request ID session-fleet-001 and the endpoint https://data.example.com/v1/query."},{"title":"Sensitive API category approval gate","prompt":"My agent wants to buy access to a KYC data product at https://kyc.provider.io/lookup for 0.10 USDC on eip155:8453 — run a preflight to verify the agent's buyer role is cleared for sensitive identity data before it commits to the payment, using request ID kyc-check-9921."},{"title":"RPC method authorization screening","prompt":"Check if my agent is allowed to call the eth_sendRawTransaction method on https://rpc.mynode.io for 0.05 USDC on Base — I want to make sure the buyer identity and policy flags are clear before it fires off the x402 payment, request ID tx-guard-772."}],"resultDescription":"Returns a JSON object containing a risk assessment with a risk_level (e.g. 'low', 'medium', 'high'), a numeric risk_score, any policy flags triggered, along with network info, product identification, identity context, and provenance metadata. A clean response with empty flags and risk_level 'low' signals the agent is authorized to proceed with the purchase.","failureModes":["Invalid or missing required query parameters (request_id, endpoint_url, chain, method, amount_usdc) return a 400 error","amount_usdc exceeding max_single_usdc triggers a policy flag or rejection","Session budget exhausted results in a high risk_score or authorization denial","Malformed chain identifier not matching CAIP-2 pattern returns validation error","Unknown or unsupported endpoint_url domain may result in high risk flags","Caller must itself pay $0.1 USDC per call via x402, so an unpaid request returns HTTP 402"],"whenToPreferThis":"Use this endpoint when an AI agent needs a governance checkpoint before executing an x402 micropayment — especially when enforcing per-transaction spending caps, session budgets, buyer role policies, or product-category sensitivity rules on Base or other EVM chains. Prefer this over ad-hoc budget checks when you need a structured risk score and audit trail for agent purchases rather than simple balance comparisons.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T18:48:07.280Z","isFirstParty":false}