Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/keys/29` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 protocol — no API keys, accounts, or subscriptions are required; callers attach an X-PAYMENT header with a signed USDC payment to each request.
The wider platform advertises four endpoint 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 share the same $0.02/request pricing. The platform claims no rate limits and instant access.
Important caveat: the `/api/v1/keys/29` endpoint's actual functionality is unclear. The description simply says "Premium API Access" with no further documentation, no OpenAPI schema, and no example request/response bodies. The crawled docs pages (/api, /pricing, /README) all returned only a "Connect wallet" prompt with no substantive content. Without documentation it is impossible to confirm what this specific endpoint returns or what input it expects beyond a POST request with a JSON content type.
Capabilities
Use cases
- —Agents needing on-demand API access without pre-registration or API keys
- —Programmatic access to utility/data endpoints with crypto micropayments
- —Testing x402 protocol integrations against a live endpoint
Fit
Best for
- —Developers or agents who want zero-signup, pay-as-you-go API access
- —x402-compatible wallets and agent frameworks on Base
- —Low-volume callers who prefer per-request billing over subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume production workloads where $0.02/request adds up significantly
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/29 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is zero documentation on what this specific endpoint does, no OpenAPI schema, no example requests or responses, and the crawled doc pages are empty. The listing is effectively a stub.
Warnings
- —No documentation available for /api/v1/keys/29 — the endpoint's actual functionality is unknown
- —No OpenAPI or schema definition found; input/output formats are unspecified
- —All doc pages (/api, /pricing, /README) returned only 'Connect wallet' with no content
- —The platform lists many endpoint categories but none are documented beyond a name and price
Citations
- —The endpoint returns a 402 challenge requesting USDC payment on Base network with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/keys/29
- —All listed endpoints cost $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/keys/29