Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com offers a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/v1/charges/7` is labeled "Premium API Access" and accepts POST requests. Payment is settled in USDC (contract 0x8335…2913 on Base) with a maximum amount of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals). No API keys, rate limits, or upfront commitments are required — each call is paid individually via the X-PAYMENT header.
The broader lowpaymentfee.com platform advertises 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 are listed at the same $0.02/request price point. However, the specific endpoint probed here (`/api/v1/charges/7`) is simply described as "Premium API Access" without further detail on what data or functionality it returns.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no description of what the Premium API Access endpoint actually returns. The endpoint is confirmed live (402 challenge captured), but the lack of documentation makes it difficult to know what to expect from a successful paid request.
Capabilities
Use cases
- —Paying per request for API access without needing API keys or subscriptions
- —Programmatic agent-driven API consumption with on-chain USDC micropayments
- —Accessing data, AI, finance, or utility endpoints with no rate limits
Fit
Best for
- —Agents or developers who want zero-signup, pay-as-you-go API access
- —x402-compatible clients on the Base network
- —Low-volume or sporadic API usage where subscriptions are wasteful
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/7 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and no documentation explaining what the endpoint actually returns. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or output schema describing what the endpoint returns on successful payment
- —The specific functionality of /api/v1/charges/7 ('Premium API Access') is undefined — unclear what data or service is provided
- —No request body schema or example responses available
Citations
- —The endpoint returns a 402 challenge with x402Version 1, accepting USDC on Base with maxAmountRequired of 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/charges/7
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02/request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/7