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/28/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 gated via the x402 protocol on the Base network.
The specific endpoint listed here accepts POST requests and is described by the provider simply as "Premium API Access." The x402 challenge advertises a maximum cost of 20,000 base units of USDC (contract 0x8335…2913 on Base), which equals $0.02 per request given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. No API keys or rate limits are advertised; access is granted purely through per-call USDC micropayments.
Documentation is extremely sparse. The provider's docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no explanation of what the `/cards/28/transactions` resource actually returns or what POST body it expects. The endpoint is live (returns a valid 402 challenge), but without documentation it is difficult to determine the actual functionality beyond the generic "Premium API Access" label.
Capabilities
Use cases
- —Retrieving card transaction data via a single paid POST request
- —Integrating x402 micropayment-gated endpoints into agent workflows
- —Accessing financial card data without API key registration
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —Agents that can settle USDC payments on Base for per-call API access
- —Use cases requiring keyless, pay-as-you-go API access
Not for
- —Production systems requiring well-documented request/response schemas
- —Users who need free or subscription-based API access without crypto wallets
- —Applications needing high-throughput bulk card transaction processing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/28/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is zero documentation: no OpenAPI schema, no request/response examples, no explanation of what the endpoint does beyond a generic label. Docs pages render only 'Connect wallet'. This is effectively a stub listing.
Warnings
- —No documentation available — all doc/API/pricing/README pages show only 'Connect wallet'
- —No OpenAPI or input/output schema provided; request body and response format are unknown
- —The endpoint path '/api/v1/cards/28/transactions' suggests card-specific data but the actual functionality is unverified
- —The generic 'Premium API Access' description provides no insight into what the endpoint returns
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/cards/28/transactions
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/cards/28/transactions
- —Platform advertises $0.02 per request, no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages all render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs