Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
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/charges/60` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader platform offers 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 listed at $0.02 per request.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The actual functionality behind `/api/v1/charges/60` (labeled "Premium API Access") is unclear — it does not correspond to any of the named endpoints on the landing page, and no description of what it returns is provided.
Capabilities
Use cases
- —Accessing data analytics and reports without subscription commitments
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) on a per-call basis
- —Fetching real-time crypto and finance data with micropayments
- —Geocoding and utility operations paid per request
Fit
Best for
- —Developers who want API access without managing API keys or subscriptions
- —Agents that need to pay per call using on-chain USDC on Base
- —Low-volume or bursty workloads where flat-rate pricing is wasteful
Not for
- —High-volume production workloads needing SLAs and guaranteed uptime documentation
- —Users who need detailed API documentation, schemas, or example responses before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/60 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the specific endpoint path '/api/v1/charges/60' is not explained anywhere on the site. The actual functionality behind this endpoint is unknown.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README all show only 'Connect wallet'
- —No OpenAPI or schema definition found
- —The endpoint path /api/v1/charges/60 does not match any of the named endpoints listed on the landing page; its actual functionality is unclear
- —No example request or response payloads available
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/charges/60
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —The platform advertises no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/60