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 set of endpoints across four 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 endpoints are priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol.
The specific endpoint at `/api/v1/transactions/222` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with no API keys or rate limits required — callers simply attach an X-PAYMENT header. The endpoint accepts POST requests and returns application/json.
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 description of what the `/api/v1/transactions/222` endpoint actually returns. The landing page lists many endpoints but provides no detail on input parameters or output formats for any of them. Without documentation, the actual functionality behind this specific endpoint is unclear.
Capabilities
Use cases
- —Programmatic access to data analytics and reporting endpoints without subscription commitments
- —AI inference tasks like sentiment analysis, summarization, and classification at micro-payment pricing
- —Fetching real-time financial data such as exchange rates, token quotes, and gas estimates
- —Utility operations like geocoding, validation, and data conversion
Fit
Best for
- —Agents or developers wanting no-signup, pay-per-call API access
- —x402-compatible clients that can settle USDC on Base
- —Low-volume or sporadic API usage where subscriptions are wasteful
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or rate-limited tiers
- —Anyone unable to transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/222 \
-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 pricing and payment details. However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty (showing only 'Connect wallet'). The purpose of the specific /api/v1/transactions/222 endpoint is unclear beyond the generic label 'Premium API Access'. This is effectively a stub listing.
Warnings
- —No documentation available — all doc/API/pricing/README pages render only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific endpoint /api/v1/transactions/222 is not listed on the landing page among the advertised APIs — its actual functionality is unknown
- —No request or response examples available anywhere in crawled content
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, on Base networkhttps://lowpaymentfee.com
- —The 402 challenge for /api/v1/transactions/222 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/222
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages show only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs