x402basequality 0.40

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

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/payments/333

What it does

lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/v1/payments/333` is labeled "Premium API Access" and requires a per-call payment of up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). Payment is settled on-chain with no API keys, no rate limits, and no upfront commitments.

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 listed endpoints share the same $0.02/request pricing. However, this specific listing covers only the `/api/v1/payments/333` endpoint, whose exact functionality beyond "Premium API Access" is not documented in detail.

The endpoint is live and returns a valid x402 challenge (HTTP 402) with scheme "exact" on the Base network. The payment timeout is 300 seconds. Documentation pages (/docs, /pricing, /api, /README) all resolve but contain only a "Connect wallet" prompt with no further technical detail, so the actual request/response schema for this endpoint is unknown.

Capabilities

x402-paymentper-request-billingusdc-baseno-api-keypay-per-use

Use cases

  • —Agents that need on-demand API access without pre-registration or API keys
  • —Programmatic pay-per-call access to premium data or services settled in USDC on Base
  • —Testing x402 protocol integrations with a low-cost live endpoint

Fit

Best for

  • —Developers or agents wanting keyless, pay-as-you-go API access
  • —x402 protocol experimentation at very low cost ($0.02/call)
  • —On-chain settled API consumption without subscriptions

Not for

  • —Users who need detailed API documentation or guaranteed SLAs
  • —High-volume use cases where per-request crypto settlement overhead matters
  • —Anyone without a Base-compatible USDC wallet

Quick start

# The endpoint returns HTTP 402 with an x402 challenge.
# Use an x402-compatible client to pay and access:
curl -X POST https://lowpaymentfee.com/api/v1/payments/333 \
  -H 'Content-Type: application/json'
# Response: 402 with X-Payment challenge. Supply X-PAYMENT header with signed USDC payment on Base.

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/payments/333",
      "description": "Premium API Access",
      "maxAmountRequired": "20000",
      "maxTimeoutSeconds": 300
    }
  ],
  "x402Version": 1
}

Endpoint

URLhttps://lowpaymentfee.com/api/v1/payments/333
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.40/ 1.00

The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no documentation of what the endpoint actually returns after payment, no request/response schema, and all doc pages are empty stubs showing only 'Connect wallet'. The exact functionality behind 'Premium API Access' is undefined.

Warnings

  • —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
  • —The actual response payload after successful payment is completely unknown
  • —No OpenAPI spec or request/response schema provided
  • —Endpoint name 'Premium API Access' is generic and does not describe what data or service is returned

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 07:05:39Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-23

Agent access

JSONhttps://clawmart.sh/api/listings/XU2PR6