x402-gated card-transactions endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com exposes a card-transactions resource at `/api/v1/cards/87/transactions` behind an x402 payment challenge. It is part of a broader platform that offers dozens of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per request, settled in USDC on the Base network.
The specific endpoint listed here (`/api/v1/cards/87/transactions`) is described only as "Premium API Access" with no further documentation on request or response schemas. The x402 challenge confirms it accepts POST requests and charges up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02. Payment is made via the x402 exact scheme to the payTo address. No API keys or rate limits are advertised; access is gated purely by the per-request micropayment.
Documentation across the site is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema, and no explanation of what data the `/cards/87/transactions` resource actually returns. The endpoint is live (returns a proper 402 challenge), but without documentation it is unclear what payload to POST or what the response structure looks like.
Capabilities
Use cases
- —Retrieving card transaction data via a single micropayment
- —Integrating pay-per-call transaction lookups into agent workflows
- —Accessing financial card data without API key registration
Fit
Best for
- —Agents that can settle x402 USDC payments on Base
- —Developers wanting keyless, pay-per-use card transaction data
- —Prototyping micropayment-gated API integrations
Not for
- —Production use requiring documented request/response schemas
- —High-volume batch processing where per-call pricing is inefficient
- —Users who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/87/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what the endpoint does, what request body it expects, or what it returns. The description 'Premium API Access' is generic and uninformative. No OpenAPI spec, no examples, and all doc pages are empty.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No request or response schema provided; unclear what data this endpoint returns
- —The path '/api/v1/cards/87/transactions' contains a hardcoded ID (87) with no explanation
- —The generic title 'Premium API Access' does not describe the endpoint's actual function
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/cards/87/transactions
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/cards/87/transactions