x402basequality 0.25

x402-gated premium API endpoint on Base, pay $0.02 per request in USDC.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/cards/88

What it does

This endpoint at `/api/v1/cards/88` is part of the lowpaymentfee.com platform, which offers a collection of x402-protocol pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. The specific `/api/v1/cards/88` resource is labeled "Premium API Access" but its exact functionality is not documented beyond that label. The platform advertises a flat $0.02 per request across all endpoints.

Payment is handled via the x402 protocol on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The probe confirms the endpoint is live, returning a 402 challenge with `maxAmountRequired` of 20,000 base units (USDC has 6 decimals, so this equals $0.02). The payment scheme is "exact" with a 300-second timeout. No API keys or rate limits are advertised — access is granted purely through the x402 payment header.

Documentation is extremely sparse. The docs, API, pricing, 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 `/api/v1/cards/88` actually returns. The broader site lists 16 endpoints across four categories, but none of them correspond to `/api/v1/cards/88`, making it unclear whether this is a standalone resource or part of an unlisted category. Prospective users should be aware that without documentation, the actual behavior of this endpoint is unknown.

Capabilities

x402-paymentusdc-basepay-per-requestno-api-keyjson-response

Use cases

  • —Accessing a premium data resource via a single micropayment without account signup
  • —Agent-driven API consumption where payment is embedded in the HTTP request
  • —Exploring x402-protocol pay-per-request patterns on Base

Fit

Best for

  • —Developers experimenting with x402 payment protocol
  • —Agents that can attach x402 payment headers automatically
  • —Users who want no-signup, no-API-key access to paid endpoints

Not for

  • —Anyone needing documented, well-specified API contracts before integrating
  • —High-volume consumers who need bulk pricing or rate-limit guarantees
  • —Users without a Base-network USDC wallet

Quick start

# The endpoint requires an X-PAYMENT header with a valid x402 payment proof.
# Using curl (you need an x402-compatible client to generate the payment):
curl -X POST https://lowpaymentfee.com/api/v1/cards/88 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402_payment_token>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/cards/88
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.25/ 1.00

The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and the purpose of '/api/v1/cards/88' is entirely undescribed. This is effectively a stub listing.

Warnings

  • —The specific endpoint /api/v1/cards/88 is not listed among the 16 documented APIs on the site — its purpose is unknown.
  • —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no actual content.
  • —No OpenAPI schema, no request body schema, and no response examples are available.
  • —The label 'Premium API Access' is generic and does not describe what the endpoint does.

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 03:03:48Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-22

Agent access

JSONhttps://clawmart.sh/api/listings/CpCRGR
x402-gated premium API endpoint on Base, pay $0.02 per request in USDC. — Clawmart · Clawmart