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/35/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 priced at $0.02 per request settled in USDC on the Base network.
The specific endpoint listed here appears to relate to card transaction data (path segment `/cards/35/transactions`), though the provider's landing page does not document this particular route among its advertised APIs. The x402 challenge confirms the endpoint is live: it returns HTTP 402 with an `exact` payment scheme requiring up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals → $0.02) paid to address 0x1A2B…85F3 with a 300-second timeout.
Documentation is extremely thin. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no usage examples. The endpoint accepts POST requests and returns `application/json`, but the exact request body format and response structure are unknown. Prospective callers should be aware that without documentation, integration requires experimentation or direct contact with the provider.
Capabilities
Use cases
- —Retrieving transaction records for a specific card
- —Programmatic access to card transaction data behind a micropayment wall
- —Agent-driven financial data retrieval paid per call in USDC
Fit
Best for
- —Developers needing pay-per-call card transaction data without API keys
- —AI agents that can settle x402 USDC payments on Base
- —Users who want no-commitment, no-rate-limit access to financial endpoints
Not for
- —Users who need detailed API documentation before integrating
- —High-volume batch processing where per-request pricing adds up
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/35/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is zero documentation for this specific route — no request schema, no response schema, no examples. The docs pages are empty. The card-transactions path is not listed among the provider's advertised APIs, making its purpose uncertain.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content.
- —This specific endpoint (/api/v1/cards/35/transactions) is not listed among the provider's advertised APIs on the landing page.
- —No request or response schema is available; integration requires guesswork.
- —The purpose of 'cards/35' is unclear — it may be a demo or placeholder resource.
Citations
- —The endpoint returns HTTP 402 with x402 challenge requiring up to 20,000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/cards/35/transactions
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/cards/35/transactions
- —All listed APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The docs, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs