Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request using USDC on the Base network, with no API keys, no rate limits, and no commitments required. The specific endpoint at `/api/v1/charges/349` 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 per call (USDC uses 6 decimals).
The platform advertises a uniform $0.02/request pricing across all its endpoints. Categories of available APIs include: 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). The x402 challenge confirms the endpoint is live and accepts POST requests with JSON responses.
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 documentation for what the "Premium API Access" endpoint actually returns or what parameters it accepts. The endpoint is confirmed live via the 402 challenge, but the lack of documentation makes it difficult to know what data or functionality this specific charge endpoint provides.
Capabilities
Use cases
- —Paying per-call for API access without managing API keys or subscriptions
- —Accessing data analytics, AI inference, or financial data via crypto micropayments
- —Integrating x402-compatible endpoints into agent workflows on Base network
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments in USDC on Base
- —Projects needing low-friction API access without signup
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume use cases where per-request pricing at $0.02 may add up
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/349 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and no meaningful documentation — the docs pages all show only 'Connect wallet'. The specific functionality of the /charges/349 endpoint is unknown beyond the label 'Premium API Access'.
Warnings
- —No OpenAPI schema or detailed documentation available
- —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
- —The specific functionality and expected input/output of /api/v1/charges/349 is undocumented
- —No request or response examples available to verify what data is returned
Citations
- —Uniform pricing of $0.02 per request across all endpointshttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/charges/349
- —Available API categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com