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/63/transactions` behind the x402 payment protocol. It accepts POST requests and requires a per-call micropayment of $0.02 in USDC on the Base network. The x402 challenge confirms the endpoint is live, returning a 402 with an `exact` payment scheme, a max amount of 20,000 base units of USDC (0.02 USD given 6 decimals), and a 300-second payment timeout.
The broader lowpaymentfee.com platform advertises a wide catalog of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and utility services — all priced at $0.02 per call with no API keys, no rate limits, and no commitments. However, the specific endpoint listed here (`/api/v1/cards/63/transactions`) is not explicitly described in the site's public catalog, and no documentation, request schema, or response schema is available for it. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no further content.
Because there is no OpenAPI spec, no request/response examples, and no documentation explaining what "card 63 transactions" means or what fields the POST body expects, the actual functionality of this endpoint remains unclear. It could relate to financial card transaction records, but this is speculative. Agents should treat this as an opaque endpoint until further documentation is published.
Capabilities
Use cases
- —Retrieving or creating card transaction records via a single paid POST call
- —Integrating pay-per-request card transaction data into agent workflows
- —Programmatic access to card-level transaction information without API key management
Fit
Best for
- —Agents that can settle x402 USDC payments on Base
- —Use cases needing keyless, per-call API access to card transaction data
- —Low-volume or sporadic access patterns where $0.02/request is cost-effective
Not for
- —High-volume batch processing where per-call fees accumulate quickly
- —Users who need detailed documentation or guaranteed SLAs before integration
- —Non-crypto workflows that cannot settle USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/63/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and confirms pricing and network, but there is zero documentation, no request/response schema, and the specific endpoint is not listed in the site's own catalog. Effectively a stub listing.
Warnings
- —No OpenAPI spec or request/response schema available
- —Endpoint /api/v1/cards/63/transactions is not listed in the provider's own public API catalog
- —All documentation pages (docs, API, pricing, README) returned only a 'Connect wallet' prompt with no content
- —Actual functionality of this endpoint is unknown — 'card transactions' is inferred from the URL path alone
Citations
- —x402 challenge returns 402 with maxAmountRequired 20000 in USDC on Base network with exact schemehttps://lowpaymentfee.com/api/v1/cards/63/transactions
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 with 6 decimals, so 20000 base units = $0.02https://lowpaymentfee.com/api/v1/cards/63/transactions
- —Platform advertises $0.02/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 further contenthttps://lowpaymentfee.com/docs