x402-gated premium API endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at `/api/v1/cards/86` is part of the lowpaymentfee.com platform, which offers a collection of x402-protocol pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. The specific resource at `/cards/86` is labeled "Premium API Access" but its exact functionality is not documented beyond that label. The platform advertises a flat $0.02 per request pricing model with no API keys, no rate limits, and instant access.
Payment is settled on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) via the x402 exact-payment scheme. The probe confirmed the endpoint is live, returning a 402 challenge with `maxAmountRequired` of 20,000 base units, which equals $0.02 (USDC uses 6 decimals). The endpoint accepts POST requests and returns `application/json`. No OpenAPI schema, detailed documentation, or example request/response payloads were found — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional content.
Because the specific behavior of `/api/v1/cards/86` is undocumented and the "Premium API Access" label is generic, agents should treat this as a low-information endpoint. The broader platform lists many other endpoints (analytics, AI, finance, utilities) all at the same price point, but none have published schemas or usage examples.
Capabilities
Use cases
- —Accessing a premium data or service endpoint with per-request USDC micropayments
- —Integrating x402-compatible agents that can autonomously pay for API calls
- —Testing x402 payment flows on the Base network
Fit
Best for
- —Agents with x402 payment capability on Base
- —Developers exploring x402 pay-per-request patterns
- —Low-volume, no-commitment API consumption without API keys
Not for
- —Users who need detailed API documentation or schemas before calling
- —High-volume use cases where per-request pricing may add up without bulk discounts
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/86 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no documentation, no OpenAPI schema, no example requests or responses, and the purpose of /api/v1/cards/86 is entirely unclear beyond the generic label 'Premium API Access'. This is effectively a stub listing.
Warnings
- —The specific functionality of /api/v1/cards/86 is completely undocumented — 'Premium API Access' is a generic label with no further explanation.
- —No OpenAPI spec, request schema, or response schema is available.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no useful content.
- —The broader platform lists many endpoints but none have published schemas or usage examples.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/cards/86
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/cards/86
- —Platform advertises $0.02 per request, no API keys, no rate limits, instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com