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 `/api/v1/cards/60` 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 listed endpoints share the same $0.02/request pricing. The endpoint accepts HTTP POST requests and returns application/json responses.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/cards/60` endpoint specifically returns. The x402 challenge confirms the endpoint is live and accepting payment negotiations, but the actual functionality behind this particular path is unclear from available materials.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand data or AI inference with crypto micropayments
- —Exploring x402 protocol integration for pay-per-call service consumption
Fit
Best for
- —Developers experimenting with x402 micropayment-gated APIs
- —AI agents that can settle USDC payments on Base for per-call access
- —Users who want zero-commitment, pay-as-you-go API access
Not for
- —Users needing detailed API documentation or guaranteed SLAs before integrating
- —Applications requiring non-crypto payment methods
- —High-volume use cases where per-request pricing may not be cost-effective compared to subscription APIs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/60 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge confirms the endpoint is live and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what /api/v1/cards/60 actually returns. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition for request or response payloads
- —The specific functionality of /api/v1/cards/60 ('Premium API Access') is completely undocumented
- —No request or response examples available anywhere in crawled materials
- —Cannot verify what data or service this endpoint actually provides
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/cards/60
- —All listed endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/cards/60