Pay-per-call premium API access on Base network via x402 protocol at $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The specific endpoint `/api/v1/transactions/301` accepts POST requests and charges 20,000 base units of USDC (USD Coin, 6 decimals) on the Base network, which equals $0.02 per request. Payment is handled inline via the X-PAYMENT header with no API keys or rate limits required.
The broader lowpaymentfee.com platform offers a suite of pay-per-call APIs spanning 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 uniformly at $0.02 per request and settle in USDC on Base.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. The specific functionality of the `/api/v1/transactions/301` endpoint beyond its title "Premium API Access" is unclear. There is no OpenAPI schema, no request/response examples, and no description of what data or service this particular endpoint returns.
Capabilities
Use cases
- —Accessing premium API services without traditional API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Programmatic agent-to-service payments without subscriptions
Fit
Best for
- —Developers wanting instant API access without signup
- —Agents needing pay-per-call endpoints with no rate limits
- —Users who prefer crypto-native micropayments over subscription billing
Not for
- —Users needing detailed API documentation or schemas before integrating
- —High-volume use cases where per-call pricing may be expensive at scale
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/301 \
-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 this endpoint is entirely unclear beyond its generic title. The docs pages are empty.
Warnings
- —No documentation available — all doc pages render only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific purpose of /api/v1/transactions/301 ('Premium API Access') is undefined
- —Cannot verify what data or service is actually returned after payment
Citations
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/301
- —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/transactions/301