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/transactions/67` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys or rate limits are required; callers simply attach an x402 payment header to each request.
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 priced at $0.02 per request.
Documentation is extremely sparse — the docs, pricing, API, 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/transactions/67` endpoint actually returns. The endpoint is live and responds with a valid x402 challenge, but without documentation it is unclear what data or functionality this specific resource provides.
Capabilities
Use cases
- —Programmatic access to API endpoints without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand paid API calls settled in USDC on Base
- —Exploring x402 protocol integration for pay-per-use services
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-as-you-go API access
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Production workloads requiring well-documented, stable API contracts
- —Users who need detailed request/response schemas before integrating
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/67 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no OpenAPI schema, no documentation beyond a landing page listing, no request/response examples, and no explanation of what this specific endpoint returns. The docs/pricing/README pages are all empty wallet-connect stubs.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or request/response schema provided; it is unknown what data /api/v1/transactions/67 returns.
- —The endpoint name 'Premium API Access' is generic and does not describe its function.
- —Cannot verify what the endpoint actually does without paying; treat with caution.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/67
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/67