x402-gated card transaction endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a card transactions resource at `/api/v1/cards/24/transactions` via the x402 payment protocol. It is part of a broader platform offering dozens of pay-per-call APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all priced at $0.02 per request settled in USDC on the Base network.
The specific endpoint listed here accepts POST requests and is gated by an x402 challenge requiring up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals). Payment is made via the "exact" scheme to the payTo address on Base. No API keys or rate limits are advertised; access is instant once payment is included in the X-PAYMENT header.
Documentation on the site is extremely thin — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the card transactions endpoint actually returns or what input it expects. The endpoint's purpose (card transaction data? virtual card management?) cannot be confirmed from available material. Prospective users should treat this as a minimally documented service.
Capabilities
Use cases
- —Retrieving or submitting card transaction data via a pay-per-call model
- —Integrating x402-compatible payment flows into agent workflows
- —Accessing financial card data without API key registration
Fit
Best for
- —Agents or developers wanting zero-signup, pay-per-request card transaction access
- —x402-native workflows that settle in USDC on Base
- —Prototyping micropayment-gated API integrations
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —High-volume production use cases where per-request pricing at $0.02 may be costly
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/24/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 no documentation, no OpenAPI schema, no request/response examples, and no explanation of what the card transactions endpoint actually does. Docs pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or input/output schema provided; the purpose and expected payload of the card transactions endpoint are unknown.
- —The meaning of 'cards/24/transactions' is unclear — it may be a demo or placeholder resource.
- —Cannot verify what data is returned or what POST body is expected.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/cards/24/transactions
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/cards/24/transactions