Pay-per-call API platform on Base via x402 — data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request 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, settled in USDC on the Base network.
The specific endpoint at `/api/v1/charges/342` is listed as "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02. Payment is made via the x402 exact scheme — no API keys, subscriptions, or rate limits are required. The platform advertises instant access with no minimums or commitments.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. It is unclear what specific data or functionality the `/api/v1/charges/342` "Premium API Access" endpoint returns, as it does not correspond to any of the named endpoints listed on the homepage. The output schema indicates it accepts HTTP POST requests.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API keys
- —Fetching real-time financial data such as token quotes, gas estimates, and exchange rates
- —Running utility operations like geocoding, validation, and data conversion on a per-call basis
- —Integrating pay-per-request data analytics into agent workflows
Fit
Best for
- —Agents needing low-cost, no-signup API access via crypto micropayments
- —Developers prototyping with multiple API categories without subscription overhead
- —x402-compatible clients on the Base network looking for $0.02/call endpoints
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads where subscription pricing would be cheaper
- —Users without Base network USDC or x402-compatible payment infrastructure
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/342 \
-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 it accepts payments. However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and the specific purpose of /api/v1/charges/342 ('Premium API Access') is unclear and doesn't match any named endpoint on the homepage. Pricing is clear ($0.02) but everything else must be inferred.
Warnings
- —No documentation available — all doc/pricing/API/README pages render only 'Connect wallet'
- —The endpoint path /api/v1/charges/342 does not correspond to any of the named API endpoints listed on the homepage; its actual functionality is unknown
- —No OpenAPI schema or request/response examples are provided
- —No information on what data or response format this specific endpoint returns
Citations
- —All endpoints are priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Payment is settled in USDC on the Base networkhttps://lowpaymentfee.com
- —maxAmountRequired is 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) which equals $0.02https://lowpaymentfee.com/api/v1/charges/342