{"id":"d9f070a8-b8ec-462a-a1f4-4296b6bef244","shortId":"hpzVHc","kind":"x402","title":"Pay-per-call email API endpoint on Base via x402, settled in USDC at $0.02/request.","tagline":"Pay-per-call email API endpoint on Base via x402, settled in USDC at $0.02/request.","description":"This endpoint at `/api/v1/emails/67` is part of the lowpaymentfee.com platform, which offers a collection of x402-protocol pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services. The specific endpoint probed here is labeled \"Premium API Access\" and accepts POST requests. Payment is settled on the Base network using USDC (contract 0x8335…2913) through the x402 exact-payment scheme.\n\nThe x402 challenge advertises a maxAmountRequired of 20,000 base units. Since USDC uses 6 decimals, this translates to $0.02 per request, consistent with the site's uniform $0.02/request pricing across all listed endpoints. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.\n\nDocumentation is extremely sparse. The /docs, /pricing, /api, and /README pages all returned only a \"Connect wallet\" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no explanation of what the `/api/v1/emails/67` endpoint actually does or what input it expects. The endpoint name and path suggest it may return or process email-related data for a resource identified by ID 67, but this is purely speculative. Without documentation or example responses, callers will need to experiment to determine the expected request body and response format.","tags":[],"capabilities":["x402-payment","usdc-settlement","base-network","pay-per-request","email-api","post-endpoint"],"categories":["data","email"],"synonyms":["email API","x402 email endpoint","pay-per-call email","lowpaymentfee email","USDC email API","Base network API","micropayment email"],"warnings":["No documentation available — /docs, /pricing, /api, and /README all return only 'Connect wallet' with no content","No OpenAPI or schema describing request/response format for /api/v1/emails/67","Purpose of the endpoint is unclear — 'Premium API Access' is a generic label with no specifics","No examples of request body or response payload available"],"endpointUrl":"https://lowpaymentfee.com/api/v1/emails/67","protocol":"x402","transport":"http","auth":{"type":"x402","details":[{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","extra":{"name":"USD Coin","version":"2"},"payTo":"0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3","scheme":"exact","network":"base","mimeType":"application/json","resource":"https://lowpaymentfee.com/api/v1/emails/67","description":"Premium API Access","outputSchema":{"input":{"type":"http","method":"GET","discoverable":true}},"maxAmountRequired":"20000","maxTimeoutSeconds":300}]},"qualityScore":"0.250","qualityRationale":"The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is zero documentation on what the endpoint does, what inputs it expects, or what it returns. No OpenAPI spec, no examples, and all doc pages are empty. This is effectively a stub 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'/api/v1/emails/67':38,199 '/docs':167 '/pricing':168 '/readme':171 '/request':17,34,130 '0.02':16,33,120,129 '000':109 '0x8335':92 '20':108 '2913':93 '6':115 '67':229 'Base network API' 'USDC email API' 'accept':79 'access':77,147 'across':132 'actual':201 'advertis':104,138 'ai/ml':61 'analyt':60 'api':6,23,57,76,140 'attach':150 'base':9,26,87,110 'base-network' 'bodi':250 'call':4,21 'caller':148,240 'challeng':103 'collect':48 'connect':177 'consist':123 'content':183 'contract':91 'crypto':64 'data':59,222 'decim':116 'determin':246 'document':162,192,236 'email':5,22,220 'email API' 'email-api' 'email-rel':219 'endpoint':7,24,36,70,135,200,209 'exact':98 'exact-pay':97 'exampl':238 'expect':207,248 'experi':244 'explan':195 'extrem':164 'financ':63 'format':253 'header':155 'id':228 'identifi':226 'infer':62 'input':205 'instant':146 'key':141 'label':74 'limit':144 'list':134 'lowpaymentfee email' 'lowpaymentfee.com':43 'maxamountrequir':106 'may':215 'micropayment email' 'name':210 'need':242 'network':88 'offer':46 'openapi':187 'page':172 'part':40 'path':212 'pay':2,19,54 'pay-per-cal':1,18 'pay-per-call email' 'pay-per-request':53 'payment':82,99,154,160 'per':3,20,55,121 'platform':44,137 'post':80 'post-endpoint' 'premium':75 'price':131 'probe':71 'process':218 'prompt':179 'proof':161 'protocol':52 'pure':233 'rate':143 'relat':221 'request':56,81,122,249 'request/response':190 'resourc':225 'respons':239,252 'return':174,216 'schema':191 'scheme':100 'servic':67 'settl':12,29,84 'simpli':149 'sinc':112 'site':126 'span':58 'spars':165 'spec':188 'specif':69 'specul':234 'substant':182 'suggest':213 'translat':118 'uniform':128 'unit':111 'usdc':14,31,90,113 'usdc-settlement' 'use':89,114 'util':66 'valid':158 'via':10,27 'wallet':178 'without':235 'x':153 'x-payment':152 'x402':11,28,51,96,102,159 'x402 email endpoint' 'x402-payment' 'x402-protocol':50","prices":[{"id":"6a063821-366d-47aa-88ec-894fba190c8e","listingId":"d9f070a8-b8ec-462a-a1f4-4296b6bef244","amountUsd":null,"unit":"per_call","nativeCurrency":"USD COIN","nativeAmount":"20000","chain":"base","payTo":"0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3","paymentMethod":"x402-usd coin","isPrimary":true,"details":{"scheme":"exact","mime_type":"application/json","accepts_all":[{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","extra":{"name":"USD Coin","version":"2"},"payTo":"0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3","scheme":"exact","network":"base","mimeType":"application/json","resource":"https://lowpaymentfee.com/api/v1/emails/67","description":"Premium API Access","outputSchema":{"input":{"type":"http","method":"GET","discoverable":true}},"maxAmountRequired":"20000","maxTimeoutSeconds":300}],"asset_contract":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","max_timeout_seconds":300},"createdAt":"2026-04-21T18:32:12.782Z"}],"sources":[{"listingId":"d9f070a8-b8ec-462a-a1f4-4296b6bef244","source":"x402_bazaar","sourceId":"https://lowpaymentfee.com/api/v1/emails/67","sourceUrl":"https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources","isPrimary":true,"firstSeenAt":"2026-04-21T18:32:12.782Z","lastSeenAt":"2026-04-22T04:02:25.533Z"}],"details":{"listingId":"d9f070a8-b8ec-462a-a1f4-4296b6bef244","quickStartSnippet":"curl -X POST https://lowpaymentfee.com/api/v1/emails/67 \\\n  -H \"Content-Type: application/json\" \\\n  -H \"X-PAYMENT: <x402-payment-proof>\" \\\n  -d '{}'","exampleRequest":null,"exampleResponse":null,"schema":{"input":{"type":"http","method":"GET","discoverable":true}},"openapiUrl":null,"agentsTxtUrl":null,"citations":[{"claim":"The x402 challenge returns maxAmountRequired of 20000 base units in USDC on Base network","source_url":"https://lowpaymentfee.com/api/v1/emails/67"},{"claim":"USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base","source_url":"https://lowpaymentfee.com/api/v1/emails/67"},{"claim":"Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access","source_url":"https://lowpaymentfee.com"},{"claim":"Documentation pages (/docs, /pricing, /api, /README) contain only 'Connect wallet' with no substantive content","source_url":"https://lowpaymentfee.com/docs"}],"useCases":["Retrieving or processing email-related data via a single paid API call","Integrating pay-per-use email functionality into agent workflows without API key management","Testing x402 protocol integrations with a low-cost endpoint"],"bestFor":["Developers experimenting with x402 payment protocol on Base","Agents needing keyless, pay-per-call API access","Low-volume or sporadic email data lookups"],"notFor":["Production email sending at scale (no documentation to confirm capabilities)","Users who need detailed API documentation or guaranteed SLAs","Non-crypto users who cannot settle payments in USDC on Base"],"kindDetails":{"x402_version":1,"resource_type":"http","bazaar_last_updated":"2026-02-17T23:13:20.251Z"},"updatedAt":"2026-04-22T04:02:25.533Z"}}