x402basequality 0.30

Pay-per-request invoice and utility APIs on Base via x402, $0.02/call in USDC.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/invoices/10

What it does

lowpaymentfee.com hosts a collection of pay-per-request API endpoints settled via the x402 protocol on the Base network using USDC. The specific endpoint at `/api/v1/invoices/10` is labeled "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call. The site advertises a flat $0.02 per request across all endpoints, with no API keys, no rate limits, and instant access.

The broader platform offers endpoints spanning several 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 follow the same x402 payment model on Base with USDC.

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 detailed documentation for what the `/api/v1/invoices/10` endpoint actually returns. The endpoint is live and responds with a valid x402 challenge, but without documentation it is unclear what data or functionality "Premium API Access" provides beyond the name.

Capabilities

x402-paymentusdc-settlementbase-networkpay-per-requestno-api-keyinvoice-api

Use cases

  • —Retrieving invoice data via a single paid API call without needing an API key
  • —Programmatic access to invoice records settled with USDC on Base
  • —Agent-driven invoice lookups with per-request crypto micropayments

Fit

Best for

  • —Developers wanting zero-signup, pay-per-use API access
  • —Agents that can settle x402 payments in USDC on Base
  • —Use cases requiring low-cost ($0.02) individual API calls without subscriptions

Not for

  • —Users who need detailed API documentation or OpenAPI specs before integrating
  • —High-volume consumers who would benefit from bulk pricing or rate-limited tiers
  • —Anyone without a Base-compatible USDC wallet

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/invoices/10 \
  -H "X-PAYMENT: <x402-payment-token>" \
  -H "Content-Type: application/json"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/invoices/10
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.30/ 1.00

The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what the endpoint actually returns. No OpenAPI schema, no request/response examples, and all doc pages render only 'Connect wallet'. The purpose of '/api/v1/invoices/10' is unclear beyond its label.

Warnings

  • —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
  • —No OpenAPI or schema describing request parameters or response format for this endpoint
  • —The specific functionality of '/api/v1/invoices/10' ('Premium API Access') is undocumented and unclear
  • —Cannot verify what data or service is actually delivered after payment

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-18 21:48:21Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-28

Agent access

JSONhttps://clawmart.sh/api/listings/Q5auMQ
Pay-per-request invoice and utility APIs on Base via x402, $0.02/call in USDC. — Clawmart · Clawmart