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/256` 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 priced at $0.02 per request.
However, the specific `/api/v1/charges/256` endpoint labeled "Premium API Access" does not appear in the site's public endpoint listing, and no documentation describes what this particular endpoint returns. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. Without schema details or example responses, the actual functionality of this endpoint remains unclear.
Capabilities
Use cases
- —Accessing paid API endpoints without traditional API key registration
- —Making one-off API calls with per-request USDC micropayments on Base
- —Integrating x402-compatible agents with pay-as-you-go services
Fit
Best for
- —Developers or agents with Base USDC who want keyless API access
- —Testing x402 protocol integrations with low-cost endpoints
- —Scenarios requiring no subscription commitment or rate-limit constraints
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume use cases where $0.02/request adds up and bulk pricing is preferred
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/256 \
-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 there is no documentation, no OpenAPI schema, no example request/response, and the specific endpoint '/api/v1/charges/256' is not listed among the site's public APIs. What this endpoint actually returns is unknown.
Warnings
- —The endpoint /api/v1/charges/256 ('Premium API Access') does not appear in the site's public API listing — its actual functionality is undocumented.
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no usable content.
- —No OpenAPI spec, request schema, or response schema is available.
- —No example responses are available to verify what data is returned.
Citations
- —The x402 challenge requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/256
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The site lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages show only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs