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/89/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 and settled in USDC on the Base network.
The specific `/cards/89/transactions` path suggests a financial or card-related transaction lookup or creation endpoint, though no detailed documentation or request/response schema is available beyond the x402 challenge metadata. The challenge advertises a `maxAmountRequired` of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02 USD. Payment is made via the x402 "exact" scheme to the specified payTo address, with a 300-second timeout.
The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof. Documentation pages (`/docs`, `/pricing`, `/api`, `/README`) all resolve but contain only a "Connect wallet" prompt with no substantive technical content, so the actual request body format and response schema for this endpoint remain undocumented.
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 financial transaction endpoints settled in USDC on Base
Fit
Best for
- —Agents needing keyless, pay-per-request access to card transaction data
- —Developers prototyping x402-based payment flows on Base
- —Scenarios where avoiding subscription commitments is preferred
Not for
- —Production use requiring well-documented request/response schemas
- —High-volume batch processing where per-request pricing is inefficient
- —Users who need fiat-only payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/89/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-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 request/response schema, and no explanation of what the /cards/89/transactions resource actually does. All doc pages return only a 'Connect wallet' stub.
Warnings
- —No request or response schema is documented; the actual payload format is unknown.
- —All documentation pages (/docs, /pricing, /api, /README) contain only a 'Connect wallet' prompt with no technical content.
- —The purpose of the /cards/89/transactions endpoint is unclear — 'Premium API Access' is a generic label applied across the platform.
- —The hardcoded card ID '89' in the path suggests this may be a demo or placeholder resource.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/cards/89/transactions
- —Platform advertises $0.02 per request, no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —Documentation pages resolve but contain only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs