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 an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are priced at $0.02 per request, paid in USDC on the Base network. The x402 protocol means there are no API keys, no accounts, and no rate limits — callers simply attach a payment header to each request.
The specific endpoint at `/api/v1/payments/193` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. The payment is settled to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation beyond the landing page is extremely sparse (docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional content). There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material. The actual functionality behind this specific endpoint and the broader catalog cannot be verified from the available information.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API key management
- —Programmatic pay-as-you-go access to data, AI, finance, or utility endpoints
Fit
Best for
- —Developers or agents wanting zero-signup, pay-per-use API access
- —x402-compatible clients on the Base network
- —Low-volume or sporadic API consumers who prefer no subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/193 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC payments on Base at $0.02. However, there is no OpenAPI spec, no request/response schema, no documentation, and no examples — the docs/pricing/API/README pages are all blank beyond a wallet-connect prompt. The actual functionality of this specific endpoint is unknown.
Warnings
- —No OpenAPI specification or request/response schema available
- —Documentation pages (docs, pricing, API, README) are effectively empty — only show 'Connect wallet'
- —The actual functionality behind '/api/v1/payments/193' ('Premium API Access') is undocumented and unclear
- —Cannot verify what data or service is returned after payment
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/payments/193
- —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 offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation, pricing, API, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs