Pay-per-call API platform on Base network via x402 — $0.02/request in USDC, 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/29` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call. No API keys, rate limits, or subscriptions are required — each request is individually settled on-chain.
The broader platform advertises multiple API categories including 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 sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/payments/29` endpoint specifically returns. The endpoint is live and responds with a valid x402 challenge, but the actual functionality behind this particular path is unclear from available material.
Capabilities
Use cases
- —Accessing pay-per-call API services without needing API keys or subscriptions
- —Making micropayments for individual API requests using USDC on Base
- —Agent-driven API consumption where each call is independently settled on-chain
Fit
Best for
- —Developers who want zero-commitment, pay-as-you-go API access
- —AI agents that need to autonomously purchase API calls via x402
- —Users who prefer on-chain USDC payments over traditional billing
Not for
- —Users needing 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/29 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the specific functionality of /api/v1/payments/29 is undescribed. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available — all doc pages render only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format
- —The specific purpose of /api/v1/payments/29 ('Premium API Access') is not explained anywhere
- —Cannot verify what data or service is actually returned after payment
- —The platform lists many API categories (AI, finance, data) but provides zero technical detail on any of them
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/29
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform advertises Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages all show only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs