x402basequality 0.25

x402-gated card-transaction endpoint on Base, paid per-call in USDC.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/cards/56/transactions

What it does

This endpoint at lowpaymentfee.com exposes a card-transactions resource at `/api/v1/cards/56/transactions` behind an x402 paywall. It accepts POST requests and settles payments in USDC on the Base network using the x402 "exact" scheme. The per-request cost is 20,000 base units of USDC (6 decimals), which equals $0.02 per call. No API keys or accounts are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.

The broader lowpaymentfee.com platform advertises a wide catalog of pay-per-call 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 at the same $0.02/request price point. However, the specific endpoint listed here is scoped to card transactions (card ID 56), and no documentation was found describing its request body schema, expected fields, or response format.

Because the crawled docs pages, pricing page, and README all returned only a "Connect wallet" stub with no substantive content, the actual behavior of this endpoint remains unclear. There is no OpenAPI spec, no example requests or responses, and no detailed documentation available. The endpoint is confirmed live (returns a proper 402 challenge), but prospective callers will need to experiment or contact the provider to understand the required POST body and response structure.

Capabilities

x402-paymentusdc-settlementbase-networkcard-transactionspay-per-callno-api-key

Use cases

  • —Retrieving transaction history for a specific card via a pay-per-call model
  • —Integrating card transaction data into agent workflows without API key management
  • —Programmatic access to card-level transaction records settled in USDC on Base

Fit

Best for

  • —Agents that need keyless, pay-per-request access to card transaction data
  • —Developers experimenting with x402 payment protocol integrations
  • —Workflows requiring on-chain USDC micropayments for API access

Not for

  • —Users who need detailed API documentation or guaranteed SLAs before integrating
  • —High-volume batch processing where per-call pricing may add up
  • —Anyone needing card transactions for cards other than ID 56 (endpoint is card-specific)

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/cards/56/transactions \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-proof>" \
  -d '{}'

Endpoint

URLhttps://lowpaymentfee.com/api/v1/cards/56/transactions
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.25/ 1.00

The endpoint is confirmed live with a valid 402 challenge and clear pricing ($0.02/request in USDC on Base). However, there is no OpenAPI spec, no documentation beyond marketing stubs, no request/response schema, and no explanation of what 'cards/56/transactions' actually returns. This is effectively a stub listing.

Warnings

  • —No documentation found — docs, pricing, README, and API pages all return only a 'Connect wallet' stub
  • —No request body schema or response schema available for this endpoint
  • —The endpoint is specific to card ID 56; it is unclear what this card represents or whether other card IDs are available
  • —The broader platform advertises many API categories but none appear documented

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 03:04:44Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-24

Agent access

JSONhttps://clawmart.sh/api/listings/QQZhTc
x402-gated card-transaction endpoint on Base, paid per-call in USDC. — Clawmart · Clawmart