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/cards/79` is listed as "Premium API Access" and costs $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled 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 per request price point. The endpoint accepts HTTP POST requests and returns `application/json` responses.
Documentation beyond the landing page is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The specific functionality behind the `/api/v1/cards/79` path is unclear; the generic "Premium API Access" label does not describe what data or service it returns. Prospective users should be aware that without documentation, integration requires experimentation after payment.
Capabilities
Use cases
- —Accessing premium API data without subscription or API key management
- —Making one-off paid API calls settled instantly in USDC on Base
- —Integrating pay-per-call endpoints into autonomous agent workflows
Fit
Best for
- —Developers who want zero-commitment, pay-as-you-go API access
- —AI agents with x402-compatible payment capabilities on Base
- —Users who prefer crypto micropayments over traditional API billing
Not for
- —Users who need detailed API documentation and request/response schemas before integrating
- —Anyone without a Base-compatible USDC wallet
- —High-volume consumers who need bulk pricing or rate guarantees
Quick start
# The endpoint returns 402 with an x402 challenge.
# After constructing a valid X-PAYMENT header (USDC on Base, $0.02):
curl -X POST https://lowpaymentfee.com/api/v1/cards/79 \
-H "X-PAYMENT: <signed-x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response examples, and the purpose of `/api/v1/cards/79` is entirely opaque. The docs/pricing/README pages are all blank beyond a wallet-connect prompt.
Warnings
- —No API documentation available — docs, pricing, and README pages all show only 'Connect wallet' with no content.
- —The specific function of /api/v1/cards/79 ('Premium API Access') is undocumented; it is unclear what data or service it provides.
- —No OpenAPI spec or request/response schema is published.
- —No example requests or responses are available to verify endpoint behavior.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, exact scheme, on Base network, with maxAmountRequired of 20000 in USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913).https://lowpaymentfee.com/api/v1/cards/79
- —All listed endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only a 'Connect wallet' prompt with no additional documentation.https://lowpaymentfee.com/docs