x402-gated card-transactions endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com exposes a card transactions resource at `/api/v1/cards/84/transactions` behind the x402 payment protocol. It accepts HTTP POST requests and requires an X-PAYMENT header carrying a USDC payment on the Base network. The maximum amount required per call is 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals), consistent with the site-wide $0.02/request pricing advertised by the provider.
The provider's landing page lists a broad catalog of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all at the same $0.02 price point and all gated via x402 on Base. However, this specific endpoint (`/cards/84/transactions`) is not listed on the homepage 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" stub with no further content.
Because there is no OpenAPI spec, no request/response examples, and no documentation beyond the generic "Premium API Access" description, the actual functionality of this endpoint is unclear. It appears to relate to card transaction data (possibly virtual card or payment card transactions), but this is inferred solely from the URL path. Agents should treat this as a low-documentation endpoint and test carefully before relying on it in production.
Capabilities
Use cases
- —Retrieving transaction history for a specific card resource
- —Programmatic access to card transaction data without API keys
- —Agent-driven financial data retrieval with per-call USDC micropayments
Fit
Best for
- —Agents that need card transaction data and can pay per request in USDC on Base
- —Developers wanting keyless, pay-as-you-go access to financial endpoints
- —Workflows requiring low-friction micropayment-gated API calls
Not for
- —Users needing detailed API documentation or guaranteed SLAs before integration
- —High-volume batch processing where $0.02/request adds up significantly
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/84/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (returns a valid x402 402 challenge) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, no examples, and the specific endpoint is not even listed on the provider's own homepage catalog. Effectively a stub listing.
Warnings
- —No API documentation available — docs, API, pricing, and README pages all return only a 'Connect wallet' stub.
- —No request or response schema provided; the functionality of /api/v1/cards/84/transactions is inferred from the URL path only.
- —This specific endpoint is not listed in the provider's homepage API catalog, raising questions about its intended audience or status.
- —The endpoint path references a hardcoded card ID (84), which may not be generally useful.
Citations
- —The x402 challenge requires a maximum of 20,000 base units of USDC on the Base network, equivalent to $0.02.https://lowpaymentfee.com/api/v1/cards/84/transactions
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/cards/84/transactions
- —The provider advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —Docs, API, pricing, and README pages returned only a 'Connect wallet' stub with no substantive content.https://lowpaymentfee.com/docs