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 USDC micropayments on the Base network. The specific endpoint `/api/v1/cards/77` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is made via the x402 exact scheme — no API keys, no rate limits, and no subscriptions required.
The broader platform advertises four categories of endpoints: 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 and settle in USDC on Base.
Note that the specific functionality behind `/api/v1/cards/77` is not documented beyond the generic "Premium API Access" label. There is no OpenAPI schema, no request/response examples, and the docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional content. Prospective users should be aware that the actual behavior of this endpoint is unclear from available documentation.
Capabilities
Use cases
- —Accessing premium API data without subscription or API key management
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven programmatic access to gated endpoints via x402 protocol
Fit
Best for
- —Developers wanting zero-commitment pay-per-call API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users needing detailed API documentation or schemas before purchasing
- —Anyone without a Base-compatible USDC wallet
- —High-volume consumers who need bulk pricing or rate guarantees
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/77 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no documentation beyond a generic label. The docs, pricing, and API pages are empty stubs. The actual functionality of /api/v1/cards/77 is unknown.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The specific functionality of /api/v1/cards/77 ('Premium API Access') is undocumented — it is unclear what data or service it returns
- —All secondary pages (docs, pricing, API, README) render only 'Connect wallet' with no usable content
- —No request body schema or response schema is provided
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 in USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/cards/77
- —All endpoints are listed at $0.02/request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com