x402-gated premium API access on Base, pay $0.02 per request in USDC — no API keys required.
What it does
This endpoint at lowpaymentfee.com provides a collection of pay-per-call APIs gated by the x402 protocol on the Base network. The specific endpoint `/api/v1/cards/61` is listed as "Premium API Access" and costs $0.02 per request, paid in USDC (USD Coin) on Base. The x402 challenge confirms the endpoint is live and accepts exact-scheme payments to address 0x1A2B…85F3 with a max amount of 20,000 base units (i.e., $0.02 given USDC's 6 decimals).
The broader lowpaymentfee.com platform advertises multiple API categories including 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 priced at $0.02 per request with no API keys, no rate limits, and no minimum commitments.
However, the specific functionality behind `/api/v1/cards/61` is not documented beyond the generic label "Premium API Access." 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 further content. The actual payload format and response structure for this particular endpoint remain unknown.
Capabilities
Use cases
- —Paying per request for API access without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Accessing premium data or utility endpoints with micropayments
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents with x402-compatible payment capabilities on Base
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —Applications requiring high-throughput batch processing with predictable flat-rate pricing
- —Users without USDC on the Base network
Quick start
# Send a POST with x402 payment header to access the endpoint
curl -X POST https://lowpaymentfee.com/api/v1/cards/61 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and the specific functionality of /api/v1/cards/61 is undocumented. Docs pages render only 'Connect wallet' with no usable content.
Warnings
- —The specific functionality of /api/v1/cards/61 ('Premium API Access') is not documented — it is unclear what data or service this endpoint returns.
- —No OpenAPI schema, request format, or response examples are available.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no further content.
- —The endpoint name 'cards/61' suggests a generic or placeholder resource; actual utility is unverified.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/cards/61
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/cards/61