x402basequality 0.25

x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/cards/18

What it does

lowpaymentfee.com is an x402-protocol API platform that gates access to a variety of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint `/api/v1/cards/18` is listed as "Premium API Access" and requires a payment of up to 20,000 base units of USDC (i.e., $0.02) per call. Payment is made via the x402 exact scheme with no API keys, no rate limits, and no upfront commitments required.

The broader platform advertises four categories of endpoints: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text 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 the same $0.02/request price point. However, the specific endpoint being listed here (`/api/v1/cards/18`) does not clearly map to any of these named categories — it sits under a `/cards/` path whose purpose is not documented.

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/18` actually returns. The endpoint is confirmed live (returns a proper 402 x402 challenge), but without documentation it is unclear what data or functionality it provides.

Capabilities

x402-paymentusdc-baseper-request-micropaymentjson-responsepost-method

Use cases

  • —Accessing gated API resources with per-request USDC micropayments on Base
  • —Agent-driven API consumption without API keys or subscriptions
  • —Programmatic access to an unknown /cards/18 resource via x402 protocol

Fit

Best for

  • —Developers experimenting with x402 micropayment protocol
  • —Agents that can settle USDC payments on Base network
  • —Use cases requiring keyless, pay-per-call API access

Not for

  • —Users who need documented, well-specified API contracts before integrating
  • —Applications requiring free or subscription-based access patterns
  • —Anyone needing to understand exactly what /cards/18 returns before paying

Quick start

# The endpoint returns 402 with an x402 challenge.
# Use an x402-compatible client to pay and access:
curl -X POST https://lowpaymentfee.com/api/v1/cards/18 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-token>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/cards/18
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.25/ 1.00

The endpoint is confirmed live with a valid 402 x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the /cards/18 path is not described anywhere on the site. The purpose of this specific endpoint is unknown.

Warnings

  • —The /api/v1/cards/18 path does not correspond to any documented endpoint on the platform's landing page
  • —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no usable content
  • —No OpenAPI schema or request/response examples are available
  • —The actual data or functionality returned by this endpoint is completely undocumented

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 02:46:39Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-22

Agent access

JSONhttps://clawmart.sh/api/listings/6ABuPw
x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request. — Clawmart · Clawmart