Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/charges/365` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader lowpaymentfee.com site offers endpoints across four 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 endpoints are listed at the same $0.02/request price point. However, the specific endpoint being listed here (`/api/v1/charges/365`) is labeled generically as "Premium API Access" and does not appear in the site's public endpoint catalog, so its exact functionality is unclear.
Payments settle on the Base L2 network to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the USDC contract at `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`. The x402 challenge specifies a 300-second timeout and uses the "exact" payment scheme. Documentation pages on the site (docs, pricing, README) all appear to require wallet connection and contain no readable content.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access to paid endpoints without subscription or signup
Fit
Best for
- —Developers or agents who want frictionless pay-per-call access without API keys
- —Users already holding USDC on the Base network
- —Low-volume or sporadic API consumers who prefer no commitments
Not for
- —Users who need detailed documentation or OpenAPI schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without access to USDC on the Base L2 network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/365 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but the specific functionality of /api/v1/charges/365 is undocumented. No OpenAPI schema, no request/response examples, and all documentation pages require wallet connection with no readable content. The endpoint doesn't appear in the site's public catalog.
Warnings
- —The endpoint /api/v1/charges/365 is not listed in the site's public API catalog — its actual functionality is unknown.
- —All documentation pages (docs, pricing, README, api) return only 'Connect wallet' with no readable content.
- —No OpenAPI spec or request/response schema is available; integration requires trial and error.
- —The exact data or service returned by this endpoint cannot be verified from available materials.
Citations
- —The x402 challenge requests maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/365
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/365
- —The site lists all endpoints at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com