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/128` is listed as "Premium API Access" and returns a 402 challenge requesting 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 — you simply attach an x402 payment header 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 listed at the same $0.02/request price point.
However, documentation is extremely thin. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled content. It is unclear what specific data or functionality the `/api/v1/charges/128` endpoint returns, as the listing title "Premium API Access" is generic and not descriptive of a concrete capability.
Capabilities
Use cases
- —Accessing data analytics and reports on a per-request payment basis without subscription
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with per-call USDC payments
- —Fetching financial data like token quotes, exchange rates, and gas estimates via micropayments
- —Using utility services like geocoding and validation without needing API keys
Fit
Best for
- —Developers who want pay-as-you-go API access without subscriptions or API key management
- —Agents and bots that can settle payments programmatically via x402 on Base
- —Low-volume or sporadic API consumers who don't want monthly commitments
Not for
- —High-volume production workloads where $0.02/request adds up and bulk pricing would be preferable
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/128 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"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 spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the endpoint name 'Premium API Access' is generic with no indication of what it actually returns. Effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific endpoint /api/v1/charges/128 has a generic name ('Premium API Access') with no description of its actual functionality
- —Cannot verify what data or service this endpoint provides beyond the payment challenge
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/charges/128
- —The platform lists endpoints 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, and Base network settlementhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/charges/128