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/36/transactions` behind the x402 payment protocol. It accepts POST requests and requires a per-call USDC payment on the Base network. The x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using the "exact" payment scheme.
The provider's landing page lists a broad catalog of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities—all priced at $0.02 per request with no API keys, no rate limits, and no minimum commitments. However, the specific endpoint being listed here (`/api/v1/cards/36/transactions`) is not explicitly documented on the landing page catalog, and no request/response schema or documentation beyond the x402 challenge was found. The docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no additional content.
Because the endpoint path suggests card transaction data and the provider description simply says "Premium API Access," the exact functionality is unclear. There is no OpenAPI spec, no example payloads, and no detailed documentation available. Prospective callers should treat this as an opaque POST endpoint returning JSON (per the mimeType in the challenge) and experiment with requests after payment to discover the actual schema.
Capabilities
Use cases
- —Retrieving card transaction records via a pay-per-call model
- —Integrating card transaction data into agent workflows without API key management
- —Programmatic access to financial card data settled in USDC on Base
Fit
Best for
- —Agents that can settle x402 USDC payments on Base
- —Developers wanting keyless, pay-per-use card transaction access
- —Crypto-native applications needing low-friction API billing
Not for
- —Users who need detailed API documentation before integrating
- —Applications requiring free or subscription-based access
- —Non-crypto workflows that cannot settle USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/36/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, and the specific endpoint is not listed in the provider's own catalog. Functionality must be guessed from the URL path alone.
Warnings
- —No OpenAPI spec or request/response schema available
- —Endpoint path /api/v1/cards/36/transactions is not listed on the provider's landing page catalog
- —Docs, API, pricing, and README pages all return only a 'Connect wallet' prompt with no content
- —Exact functionality and required POST body are unknown
Citations
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/cards/36/transactions
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/cards/36/transactions
- —Provider advertises $0.02 per request, no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages show only 'Connect wallet' with no additional contenthttps://lowpaymentfee.com/docs