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/56` is labeled "Premium API Access" and requires a maximum of 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 listed endpoints are priced at $0.02 per request.
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 example payloads available. The specific functionality behind the `/api/v1/payments/56` endpoint name "Premium API Access" is not described beyond its title, making it unclear what data or service it actually returns. The x402 challenge is live and well-formed, confirming the endpoint is operational, but the lack of documentation significantly limits usability.
Capabilities
Use cases
- —Accessing premium API data with per-request 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 that need keyless, pay-as-you-go API access
- —Low-volume consumers who want no subscription commitments
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads requiring SLA guarantees
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/56 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint is operational at $0.02/request in USDC on Base. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the actual functionality of this specific endpoint is undescribed. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —The specific functionality of /api/v1/payments/56 ('Premium API Access') is not described anywhere
- —No request or response schema is documented; callers cannot know what to send or expect back
- —No OpenAPI or machine-readable spec available
Citations
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/56
- —USDC asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/56
- —Platform advertises $0.02/request, no API keys, no rate limits, instant accesshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only 'Connect wallet'https://lowpaymentfee.com/docs