Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
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/144` is listed as "Premium API Access" and accepts POST requests with payment via USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base). The maximum amount required per call is 20,000 base units of USDC, which at 6 decimals equals $0.02 USD.
The broader platform advertises multiple API categories including 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. The platform emphasizes no API keys, no rate limits, and instant access.
However, the specific functionality behind the `/api/v1/charges/144` endpoint is unclear — the description is simply "Premium API Access" with no further documentation about what data or service it returns. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no substantive content. Without an OpenAPI schema, request/response examples, or detailed documentation, the actual capabilities of this specific endpoint remain opaque.
Capabilities
Use cases
- —Accessing paid API endpoints without needing to register or manage API keys
- —Making one-off API calls with instant USDC micropayments on Base
- —Integrating pay-per-use services into agent workflows via x402 protocol
Fit
Best for
- —Developers who want keyless, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone without access to USDC on the Base network
- —High-volume consumers who would benefit from bulk pricing or subscriptions
Quick start
# The endpoint requires an x402 payment header with USDC on Base.
# 1. Send a POST to get the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/charges/144
# 2. Parse the 402 response, construct an X-PAYMENT header
# with a signed USDC transfer of 0.02 USDC, then retry:
curl -X POST https://lowpaymentfee.com/api/v1/charges/144 \
-H "X-PAYMENT: <signed-payment-token>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge), and pricing is clear ($0.02 USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality behind this specific endpoint is completely undocumented. The docs/pricing/API pages are all empty beyond a wallet connect prompt.
Warnings
- —The specific functionality of /api/v1/charges/144 ('Premium API Access') is undocumented — it is unclear what data or service this endpoint provides.
- —No OpenAPI schema, request body format, or response examples are available.
- —All documentation pages (docs, pricing, API, README) returned only 'Connect wallet' with no substantive content.
- —The platform lists many API categories (AI, finance, data, etc.) but none of these claims can be verified from the crawl material.
Citations
- —Endpoint returns 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/charges/144
- —maxAmountRequired is 20000 base units of USDC (0.02 USD at 6 decimals)https://lowpaymentfee.com/api/v1/charges/144
- —Platform lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories all at $0.02/requesthttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com