x402-gated card-transaction 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/70/transactions` behind an x402 payment challenge. It is part of a broader platform that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per request, settled in USDC on the Base network.
The specific endpoint listed here accepts HTTP POST requests and is described by the provider simply as "Premium API Access." The x402 challenge advertises a maximum amount of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme to the payTo address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3, with a 300-second timeout. No API keys or rate limits are advertised; access is gated purely by the per-request micropayment.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema, and no example payloads available. The exact functionality of the `/cards/70/transactions` resource (whether it returns transaction history, creates transactions, or something else) cannot be determined from the available material.
Capabilities
Use cases
- —Querying or creating card transaction records via a pay-per-call model
- —Integrating card transaction data into agent workflows without API key management
- —Programmatic access to card-level transaction information settled in USDC on Base
Fit
Best for
- —Developers wanting keyless, pay-per-request card transaction access
- —AI agents that can settle x402 micropayments on Base
- —Users who prefer crypto-native billing over subscription plans
Not for
- —Anyone needing detailed API documentation or request/response schemas before integrating
- —High-volume use cases where $0.02/request adds up (no volume discounts documented)
- —Users who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/70/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the actual functionality of the /cards/70/transactions resource is undocumented. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or input/output schema provided; request body format and response structure are unknown.
- —The exact purpose of /api/v1/cards/70/transactions (read vs. write, what 'cards/70' refers to) is not documented anywhere in the crawl material.
- —This specific endpoint path does not appear in the provider's own homepage API listing, raising questions about its intended use.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/cards/70/transactions
- —All endpoints on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com