{"uid":"cap_aPR0iRLoEbScsUjDJzESC","slug":"x402-trust-discovery-api-onchain-token-price-05a677b3","name":"x402 Trust & Discovery API — Onchain Token Price","description":"Independent pre-purchase safety and reputation checks for x402 and MPP endpoints, plus keyless onchain data on Base. Accepts BOTH EIP-3009 and Circle Gateway credentials — only 141 of 788 Base-payable resources do, and a single-credential buyer is locked out of 53.8% of this market on one rail or 28.3% on the other. GET /v1/guard?url=&credential= answers whether the credential you carry can pay a given endpoint at all, before you try. Searching this market for \"is this API endpoint a scam\" returns registries and explorers but no dedicated service; that gap is what /v1/guard fills, inspecting an endpoint WITHOUT paying it and returning a go / test-with-minimum / do-not-pay verdict backed by onchain settlement history.","url":"https://gkyf2bs3b4p35hwwg5zzsnejeu.srv.us/v1/onchain/price?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"size":{"type":"number","description":"Trade size in USD to quote at. Defaults to 100."},"token":{"type":"string","description":"ERC-20 contract address on Base to price."}}},"responseSchema":{"type":"json","example":{}},"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":"down","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_ybr0PwGkfbApuspLF-5WJ","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":"Returns the onchain price of a Base ERC-20 token for a given trade size in USD","exampleAgentPrompt":"What's the current onchain price for the token at contract address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base for a $100 trade?","exampleUseCases":[{"title":"Pre-trade token price check","prompt":"Before I swap, can you look up the onchain price on Base for the token at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 for a $250 trade size?"},{"title":"DeFi portfolio valuation","prompt":"Get me the current Base onchain price for the ERC-20 at contract 0x4200000000000000000000000000000000000006 assuming a $1000 trade size so I can value my position."},{"title":"Token price discovery before x402 payment","prompt":"I want to know what onchain price I'd get for the token 0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb on Base for a $50 USD trade before I commit to anything."}],"resultDescription":"Returns onchain price data for the specified ERC-20 token on Base, calibrated to the requested trade size in USD. Likely includes a price quote or rate reflecting current liquidity conditions for that position size.","failureModes":["Invalid or non-existent ERC-20 contract address returns an error","Token with no onchain liquidity on Base cannot be priced","Trade size of zero or negative value may be rejected","Endpoint unavailable or server error returns non-200 response","Stale or low-liquidity token may return inaccurate quote"],"whenToPreferThis":"Use this endpoint when you need a keyless, no-payment-required onchain price quote for a Base ERC-20 token before executing a trade or making a payment decision. It is particularly useful in x402 agent workflows where you want to understand token value without committing funds. Prefer this over DEX APIs when you want a simple REST-based price lookup with no wallet interaction.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-03T08:26:03.089Z","isFirstParty":false,"canonicalSlug":"x402-trust-discovery-api-onchain-token-price-05a677b3"}