Pay-per-request API platform on Base via x402 — data, AI, finance, and utility endpoints at $0.02/call.
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, paid in USDC on the Base network.
The specific endpoint at `/api/v1/charges/230` 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 additional technical content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what any endpoint actually returns. The endpoint is confirmed live (402 challenge captured), but without documentation it is unclear what inputs the POST body expects or what the response payload looks like for this particular "Premium API Access" endpoint.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without subscription
- —Fetching real-time financial data like token quotes, exchange rates, and gas estimates on a per-call basis
- —Running data analytics queries and exporting data with per-request billing
- —Using utility services like geocoding, validation, and conversion without API key management
Fit
Best for
- —Agents or developers who want zero-setup, pay-as-you-go API access
- —Use cases requiring low-cost micropayments per API call ($0.02)
- —Projects already operating on the Base network with USDC
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume use cases where subscription pricing would be more cost-effective
- —Developers who cannot transact in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/230 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and the landing page lists available endpoints with pricing. However, documentation pages are effectively empty (only 'Connect wallet'), there is no OpenAPI spec, no request/response schemas, and no examples. The specific 'Premium API Access' endpoint at /charges/230 has no description of what it does beyond its title. This is essentially a stub listing.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) contain no usable content — only a 'Connect wallet' prompt
- —No OpenAPI or schema documentation available for any endpoint
- —The specific endpoint /api/v1/charges/230 ('Premium API Access') has no description of its functionality, expected inputs, or response format
- —The endpoint path pattern (/charges/230) does not match any of the documented API categories on the landing page, making its purpose unclear
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —Payment in USDC on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/charges/230
- —Endpoint categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com