x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402 protocol API marketplace that gates access to a variety of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint at `/api/v1/products/65` is listed as "Premium API Access" and accepts POST requests with payment via the x402 exact scheme. The maximum amount required is 20,000 base units of USDC (0x8335…), which equals $0.02 per request given USDC's 6 decimal places.
The broader platform advertises four categories of APIs: 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 the same $0.02/request price point. The platform emphasizes no API keys, no rate limits, no minimums, and instant access.
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. The `/api/v1/products/65` endpoint itself is not explicitly listed on the homepage among the available APIs, so its exact functionality is unclear. The x402 challenge confirms it is live and accepts POST requests returning application/json, but what data it returns is unknown.
Capabilities
Use cases
- —Paying per-request for API access without needing API keys or subscriptions
- —Accessing data, AI, finance, or utility endpoints via crypto micropayments
- —Integrating x402-compatible agents with low-cost API calls on Base
Fit
Best for
- —Developers wanting keyless, pay-per-use API access
- —x402-compatible AI agents that can settle USDC on Base
- —Projects needing low-friction API access without signup
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume use cases where per-request pricing may not be cost-effective
- —Developers who cannot transact in USDC on the Base network
Quick start
# The endpoint requires an X-PAYMENT header with a valid x402 payment proof.
# Using curl as an example (you need an x402 client to generate the header):
curl -X POST https://lowpaymentfee.com/api/v1/products/65 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is no OpenAPI schema, no request/response examples, and no meaningful documentation. The specific endpoint /api/v1/products/65 is not listed among the homepage's advertised APIs, making its purpose unclear. Effectively a stub listing.
Warnings
- —No OpenAPI schema or detailed documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet'
- —The endpoint /api/v1/products/65 is not listed among the homepage's advertised APIs; its specific functionality is unknown
- —No request body schema or response examples are available anywhere in the crawled material
- —All non-homepage pages returned minimal content, suggesting the site may be incomplete or require wallet connection to render
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/products/65
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/products/65
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers APIs in Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com