Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/payments/210` is labeled "Premium API Access" and charges up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an x402 payment header to each request.
The site lists four endpoint categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints share the same $0.02/request pricing. However, documentation beyond the landing page is essentially empty (all sub-pages only show "Connect wallet"), so the actual request/response schemas, supported parameters, and data sources for each endpoint are unknown.
The `/api/v1/payments/210` endpoint returned a valid x402 challenge (HTTP 402) confirming it is live. It accepts POST requests, settles via the "exact" scheme on Base using USDC (contract 0x8335…2913), and pays to address 0x1A2B…85F3 with a 300-second timeout. Because no OpenAPI spec, example payloads, or detailed docs were found, the actual functionality behind this specific endpoint remains opaque.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification) without API key management
- —Fetching real-time crypto gas estimates or token quotes with per-call payment
- —Geocoding or data validation as a utility microservice settled in USDC
- —Exporting analytics data or generating reports on a pay-as-you-go basis
Fit
Best for
- —AI agents that can settle x402 payments in USDC on Base
- —Developers wanting zero-commitment, keyless API access
- —Low-volume or bursty workloads where per-request pricing is economical
Not for
- —High-volume production workloads needing SLAs and guaranteed uptime
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/210 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (valid 402 challenge) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no examples, and all documentation pages are empty stubs. The actual functionality of the /api/v1/payments/210 'Premium API Access' endpoint is completely undocumented.
Warnings
- —All documentation pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no actual content.
- —No OpenAPI or schema available — request and response formats are unknown.
- —The specific purpose of /api/v1/payments/210 ('Premium API Access') is unclear; it does not map to any of the named endpoints on the landing page.
- —No evidence of the actual data sources, model providers, or service quality behind any listed endpoint.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/210
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC contract used is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/210