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/payments/370` 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.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/payments/370` endpoint specifically returns. The endpoint is live (402 challenge confirmed), but without documentation it is unclear what input parameters are expected or what the response payload looks like.
Capabilities
Use cases
- —Accessing premium API endpoints without traditional API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven API consumption with per-request crypto payments
Fit
Best for
- —Developers wanting zero-signup API access via crypto payments
- —AI agents that can attach x402 payment headers autonomously
- —Users who prefer pay-as-you-go pricing with no commitments
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who want bulk/subscription pricing
- —Developers without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/370 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and no description of what this specific endpoint does beyond the generic label 'Premium API Access'. The listing is effectively a stub.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README all render only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific purpose of /api/v1/payments/370 ('Premium API Access') is undefined — it is unclear what data or service it provides
- —Cannot verify what the endpoint actually returns upon successful payment
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/payments/370
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/370
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com