x402-gated card-transaction 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/17/transactions` behind the x402 payment protocol. When called without payment, it returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) on the Base network. Payment is settled on-chain to the specified wallet address using the "exact" scheme.
The broader lowpaymentfee.com platform advertises a suite of pay-per-request APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments. However, this specific endpoint (`/api/v1/cards/17/transactions`) is not listed on the homepage and its exact functionality is unclear — the path suggests it relates to transactions associated with a particular card resource (card ID 17), but no documentation, request schema, or response schema is available.
The site's docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. Without documentation or an OpenAPI spec, the input/output contract for this endpoint is unknown. The x402 challenge confirms the endpoint is live and accepts POST requests, but what data it expects or returns cannot be determined from available material.
Capabilities
Use cases
- —Retrieving or creating transactions associated with a card resource via a single paid API call
- —Integrating pay-per-request card transaction data into agent workflows without API key management
- —Programmatic access to card transaction records settled via on-chain USDC micropayments
Fit
Best for
- —Developers wanting keyless, pay-per-call access to card transaction data
- —AI agents that can settle x402 USDC payments on Base
- —Projects needing low-friction API access without subscriptions
Not for
- —Users who need documented request/response schemas before integrating
- —High-volume use cases where $0.02/request adds up significantly
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/17/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI spec, no request/response schema, and the docs pages are empty. The specific endpoint path is not listed among the site's advertised APIs, making its purpose unclear.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided for this endpoint
- —This specific endpoint (/api/v1/cards/17/transactions) is not listed among the site's advertised APIs
- —The purpose and data contract of this endpoint are unknown — 'card transactions' is inferred solely from the URL path
- —The broader site lists many API categories but none appear to have public documentation
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/cards/17/transactions
- —All listed APIs are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform advertises APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs