x402basequality 0.35

x402-gated premium API access on Base, pay $0.02 per request in USDC with no API keys.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/charges/168

What it does

This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The site hosts a broad catalog of pay-per-call APIs spanning data & analytics, 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 priced at $0.02 per request, settled in USDC on Base.

The specific endpoint `/api/v1/charges/168` is labeled "Premium API Access" and returns a standard x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals = $0.02). Payment is made via the x402 exact scheme with no API keys or rate limits required. The payTo address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 and the maximum timeout is 300 seconds.

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, and no description of what data or functionality this particular charge endpoint actually returns. The site's landing page lists many API paths but does not document their inputs or outputs. Without additional documentation it is unclear what payload to send or what response to expect from this specific endpoint.

Capabilities

x402-paymentusdc-settlementbase-networkpay-per-requestno-api-keyno-rate-limit

Use cases

  • —Accessing premium data or AI endpoints without traditional API key registration
  • —Making one-off API calls with instant USDC micropayments on Base
  • —Agent-driven workflows that need keyless, permissionless API access

Fit

Best for

  • —Developers who want pay-per-use API access without subscriptions
  • —AI agents that can settle x402 payments autonomously on Base
  • —Users who prefer crypto-native micropayments over traditional billing

Not for

  • —Users who need detailed API documentation or guaranteed SLAs before integrating
  • —High-volume consumers who would benefit from bulk pricing or subscription plans
  • —Anyone without a Base-compatible wallet or USDC balance

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/charges/168 \
  -H "Content-Type: application/json"
# Returns 402 with x402 challenge; attach X-PAYMENT header with valid payment proof 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/charges/168",
      "description": "Premium API Access",
      "maxAmountRequired": "20000",
      "maxTimeoutSeconds": 300
    }
  ],
  "x402Version": 1
}

Endpoint

URLhttps://lowpaymentfee.com/api/v1/charges/168
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.35/ 1.00

The x402 challenge is live and well-formed, confirming the endpoint exists and costs $0.02 USDC on Base. However, there is no documentation, no OpenAPI spec, no request/response schema, and no explanation of what this specific endpoint actually does beyond the generic label 'Premium API Access'. The docs pages are empty stubs.

Warnings

  • —No API documentation available — /docs, /api, /pricing, and /README all render only a wallet connect prompt
  • —No OpenAPI or schema describing request inputs or response outputs for this endpoint
  • —The label 'Premium API Access' is generic and does not clarify what data or functionality is returned
  • —Cannot determine what POST body to send to receive a useful response after payment

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 03:19:57Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-24

Agent access

JSONhttps://clawmart.sh/api/listings/TtNLwW
x402-gated premium API access on Base, pay $0.02 per request in USDC with no API keys. — Clawmart · Clawmart