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 at /api/v1/payments/272 is labeled "Premium API Access" and charges up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys, accounts, or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises several API 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 $0.02 per request. However, the specific endpoint probed here (/api/v1/payments/272) does not clearly map to any of these named services — its description is simply "Premium API Access" with no further documentation on what it returns.
The site's documentation pages (/docs, /api, /pricing, /README) all returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response examples, and no detailed documentation available. The endpoint is confirmed live (returns a valid 402 challenge), but the lack of documentation about what this specific endpoint actually does is a significant gap.
Capabilities
Use cases
- —Accessing premium API services with per-call USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-use API access
- —Low-volume callers who want no subscription commitments
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/272 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no documentation, no OpenAPI spec, no request/response examples, and the endpoint description ('Premium API Access') gives no indication of what data or service it actually provides. The docs, pricing, and README pages are all empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all return only 'Connect wallet' with no content
- —The endpoint /api/v1/payments/272 has no description beyond 'Premium API Access'; it is unclear what service or data it provides
- —No OpenAPI spec or request/response schema available
- —This endpoint path does not match any of the named APIs listed on the homepage
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/272
- —All listed APIs are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform lists Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) contain only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs