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/345` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an X-PAYMENT header with a valid x402 payment proof to each request.
The broader platform 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 priced at $0.02 per request.
However, the specific endpoint `/api/v1/charges/345` does not clearly map to any of the named services listed on the site. Its description is simply "Premium API Access," and there is no documentation, OpenAPI schema, or example request/response available for this or any other endpoint. The docs, pricing, and API pages all render only a "Connect wallet" prompt with no further content. Without schema details or documentation, it is unclear what payload this endpoint expects or what it returns.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access to data, AI, finance, or utility endpoints without subscriptions
Fit
Best for
- —Developers or agents who want to pay per call without API key management
- —Users already holding USDC on Base who want frictionless API access
- —Low-volume or bursty workloads where subscription pricing is wasteful
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume production workloads requiring SLAs or guaranteed uptime
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/345 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no OpenAPI schema, no documentation beyond a landing page listing, no example requests or responses, and the specific endpoint path (/api/v1/charges/345) does not correspond to any named service. The docs pages are empty. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The endpoint path /api/v1/charges/345 does not match any named service on the site — its actual functionality is unknown
- —All documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no content
- —No example request or response payloads are available to confirm what this endpoint does
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x8335…) on Base networkhttps://lowpaymentfee.com/api/v1/charges/345
- —All endpoints are priced at $0.02 per 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