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 `/api/v1/charges/88` is listed as "Premium API Access" and returns a standard x402 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals) per call. No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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, the specific endpoint being listed here (`/api/v1/charges/88`) is labeled only as "Premium API Access" and does not appear in the site's public API directory, so its exact functionality is unclear.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed description of what this particular endpoint returns. Callers should treat this as an exploratory endpoint until more documentation becomes available.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without traditional API key signup
- —Agent-driven workflows that need to pay per call using on-chain USDC
- —Testing x402 protocol integrations on Base network
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —AI agents that can autonomously pay for API calls via crypto
- —Users who want no-signup, no-rate-limit API access
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Production workloads requiring well-documented request/response schemas
- —Users without access to USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/88 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no OpenAPI schema, no documentation, no request/response examples, and the specific endpoint's functionality is not described anywhere on the site. The listing is effectively a stub.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content
- —The endpoint /api/v1/charges/88 does not appear in the site's public API directory; its actual functionality is unknown
- —No request body schema or response schema is documented anywhere
- —No OpenAPI or machine-readable API specification found
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/charges/88
- —All listed endpoints are priced at $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com