x402-gated card-transactions endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com exposes a POST resource at `/api/v1/cards/94/transactions` behind an x402 payment challenge. The provider's site describes it as "Premium API Access" but provides no further documentation on what the cards/transactions resource actually returns or what input it expects. The x402 challenge confirms the endpoint is live, accepting USDC (contract 0x8335…2913) on the Base network with a maximum amount of 20,000 base units, which equals $0.02 (USDC uses 6 decimals). Payment is settled on-chain to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using the "exact" scheme.
The provider's landing page lists a broad catalog of API categories — data & analytics, AI & ML, finance & Web3, and infrastructure utilities — all priced at $0.02 per request with no API keys, no rate limits, and instant access. However, the specific `/api/v1/cards/94/transactions` path does not appear in the advertised catalog, and no documentation pages returned meaningful content (all showed only "Connect wallet"). Without an OpenAPI spec, request/response schemas, or usage examples, it is unclear what data this endpoint provides or what POST body it expects. The "cards/94/transactions" path suggests it may relate to card transaction data or a financial/payment card resource, but this is speculative.
Capabilities
Use cases
- —Retrieving or submitting card transaction data via a pay-per-call model
- —Integrating x402-gated financial endpoints into agent workflows
- —Accessing premium card-related data without traditional API key provisioning
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —Agents that can settle USDC micropayments for per-call API access
- —Use cases requiring keyless, on-demand API access
Not for
- —Production use requiring documented request/response schemas
- —High-volume use cases where per-call pricing may add up without volume discounts
- —Users who need clear documentation before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/94/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response schema, and the specific endpoint path is not listed in the provider's own catalog. Effectively a stub listing.
Warnings
- —No documentation available — all doc pages return only 'Connect wallet' with no content
- —The specific path /api/v1/cards/94/transactions does not appear in the provider's advertised API catalog
- —No request or response schema is available; input format is unknown
- —The purpose of this endpoint is unclear — 'Premium API Access' is a generic label
Citations
- —x402 challenge returns maxAmountRequired of 20000 in USDC (6 decimals) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/cards/94/transactions
- —Provider advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/cards/94/transactions