x402basequality 0.30

x402-gated API suite on Base: analytics, 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/20

What it does

lowpaymentfee.com offers a collection of pay-per-call API endpoints gated by the x402 protocol, settling payments in USDC on the Base network. The specific endpoint `/api/v1/cards/20` is listed as "Premium API Access" and costs $0.02 per request (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.

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 listed endpoints share the same $0.02/request pricing.

Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The x402 challenge confirms the endpoint is live and accepts POST requests, but the actual functionality behind `/api/v1/cards/20` is unclear — the name "Premium API Access" and the path segment "cards/20" do not map obviously to any of the advertised API categories.

Capabilities

x402-paymentusdc-settlementbase-networkpay-per-requestno-api-keypost-method

Use cases

  • —Programmatic access to pay-per-call endpoints without managing API keys or subscriptions
  • —Agent-driven workflows that need on-demand API calls settled in USDC on Base
  • —Exploring x402 protocol integration with a low-cost test endpoint

Fit

Best for

  • —Developers experimenting with x402 payment protocol
  • —Agents that need keyless, pay-as-you-go API access on Base
  • —Low-volume callers who prefer per-request billing over subscriptions

Not for

  • —Users who need detailed API documentation or OpenAPI specs before integrating
  • —High-volume production workloads requiring SLAs or guaranteed uptime
  • —Anyone needing clarity on what data or functionality the /cards/20 endpoint actually returns

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/cards/20 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-token>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/cards/20
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.30/ 1.00

The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is zero documentation on request/response schemas, no OpenAPI spec, and the specific purpose of the /cards/20 endpoint is unexplained. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.

Warnings

  • —No OpenAPI spec or request/response schema available
  • —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
  • —The purpose and expected input/output of /api/v1/cards/20 ('Premium API Access') is unclear and does not match any of the advertised API categories
  • —No examples or error documentation found

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 02:47:02Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-22

Agent access

JSONhttps://clawmart.sh/api/listings/W9spqj
x402-gated API suite on Base: analytics, AI, finance, and utility endpoints at $0.02/request. — Clawmart · Clawmart