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-enabled API marketplace that exposes a variety of endpoints across data & analytics, AI & machine learning, finance & Web3, and infrastructure/utility categories. All endpoints are pay-per-request using USDC on the Base network, with no API keys, no rate limits, and no minimum commitments required.
The specific endpoint `/api/v1/cards/62` is listed as "Premium API Access" and accepts POST requests. It charges up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals, so 20000 / 10^6 = $0.02). Payment is handled via the x402 protocol's exact scheme, where callers include an X-PAYMENT header with a signed payment to the specified payTo address.
The broader platform advertises additional endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02/request price point. However, documentation pages (docs, pricing, README) returned only a "Connect wallet" prompt with no substantive content, so the actual behavior and response schemas of these endpoints remain undocumented.
Capabilities
Use cases
- —Accessing premium API data without traditional API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven workflows that need pay-as-you-go endpoint access
Fit
Best for
- —Developers wanting zero-signup API access via crypto micropayments
- —AI agents that can settle x402 payments autonomously
- —Users who prefer per-request billing over subscription plans
Not for
- —Users who need detailed API documentation and response schemas before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/62 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no documentation of request/response formats, no examples, and all doc pages return only 'Connect wallet' with no content. The actual functionality behind '/api/v1/cards/62' is completely opaque.
Warnings
- —No documentation available — all doc/pricing/README pages return only 'Connect wallet' with no content
- —No request or response schema provided; the actual behavior of /api/v1/cards/62 is unknown
- —The endpoint name 'Premium API Access' and path '/api/v1/cards/62' give no indication of what data or service is returned
- —Cannot verify whether the advertised AI, finance, and utility endpoints actually function
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 in USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/cards/62
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com