x402basequality 0.25

x402-gated API suite: analytics, AI, finance, and utility endpoints at $0.02/request on Base.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/cards/40

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 at `/api/v1/cards/40` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys or rate limits are advertised — callers simply attach an X-PAYMENT header with a valid x402 payment proof.

The broader platform advertises endpoints across four categories: 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.

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 the `/api/v1/cards/40` endpoint specifically returns. The endpoint is confirmed live (402 challenge captured), but without documentation it is unclear what data or functionality "Premium API Access" actually provides.

Capabilities

x402-paymentusdc-settlementbase-networkpay-per-requestno-api-keyjson-response

Use cases

  • —Programmatic access to a pay-per-call API without managing API keys or subscriptions
  • —Agent-driven workflows that need on-demand endpoint access settled in USDC on Base
  • —Testing x402 payment flows against a live endpoint

Fit

Best for

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

Not for

  • —Users who need detailed documentation or guaranteed SLAs before integrating
  • —High-volume production workloads requiring well-documented, battle-tested APIs

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/cards/40 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-proof>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/cards/40
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.25/ 1.00

The endpoint is live and returns a valid x402 challenge, but documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and no explanation of what '/api/v1/cards/40' actually returns. The listing is a stub.

Warnings

  • —No documentation available — all doc/pricing/README pages render only 'Connect wallet'
  • —No OpenAPI or schema describing request parameters or response format
  • —The purpose of '/api/v1/cards/40' ('Premium API Access') is completely undocumented
  • —Cannot verify what data or functionality any of the advertised endpoints actually provide

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 02:51:17Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-22

Agent access

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