x402basequality 0.35

Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/transactions/323

What it does

lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, paid in USDC on the Base network with no API keys, rate limits, or subscriptions required. The specific endpoint at `/api/v1/transactions/323` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02, since USDC uses 6 decimals) on Base.

The platform advertises categories including 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 (geocoding, validation, conversion, generation). However, the crawled documentation pages (/docs, /api, /pricing, /README) all returned only a "Connect wallet" prompt with no substantive content, so the actual functionality behind these endpoints is unverified. There is no OpenAPI schema, no example request/response documentation, and no detailed description of what the `/api/v1/transactions/323` endpoint specifically does beyond its title "Premium API Access."

Capabilities

x402-paymentusdc-base-networkpay-per-requestno-api-keyjson-responsepost-method

Use cases

  • —Accessing premium API data without subscription or API key management
  • —Making one-off paid API calls settled in USDC on Base
  • —Agent-driven workflows that need instant, keyless API access

Fit

Best for

  • —Developers wanting frictionless pay-per-use API access via crypto
  • —AI agents that can settle x402 payments autonomously
  • —Users who prefer no-commitment, no-signup API consumption

Not for

  • —Users who need detailed API documentation or OpenAPI specs before integrating
  • —High-volume consumers who would benefit from bulk pricing or subscriptions
  • —Users without access to USDC on the Base network

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/transactions/323 \
  -H "Content-Type: application/json"
# Returns 402 with x402 payment challenge; attach X-PAYMENT header with valid USDC payment to access.

Example

Response

{
  "error": "X-PAYMENT header is required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3",
      "scheme": "exact",
      "network": "base",
      "mimeType": "application/json",
      "resource": "https://lowpaymentfee.com/api/v1/transactions/323",
      "description": "Premium API Access",
      "maxAmountRequired": "20000",
      "maxTimeoutSeconds": 300
    }
  ],
  "x402Version": 1
}

Endpoint

URLhttps://lowpaymentfee.com/api/v1/transactions/323
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.35/ 1.00

The endpoint is live and returns a valid x402 challenge, and the landing page lists many API categories. However, there is no OpenAPI schema, no documentation, no example requests or responses, and no description of what this specific endpoint actually returns after payment. The docs/pricing/README pages are all empty beyond a wallet prompt.

Warnings

  • —No OpenAPI or schema documentation available for any endpoint
  • —All documentation pages (/docs, /api, /pricing, /README) returned only 'Connect wallet' with no content
  • —The specific functionality of /api/v1/transactions/323 ('Premium API Access') is completely undocumented
  • —Cannot verify that the advertised AI, analytics, finance, or utility endpoints actually function as described

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 13:04:35Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-22

Agent access

JSONhttps://clawmart.sh/api/listings/SBPB79
Pay-per-call API platform on Base network via x402 — $0.02/request in USDC. — Clawmart · Clawmart