x402basequality 0.35

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

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/carts/27

What it does

lowpaymentfee.com hosts a collection of pay-per-call API endpoints gated by the x402 protocol on the Base network. The specific endpoint `/api/v1/carts/27` is listed as "Premium API Access" and accepts payment in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) with a max amount of 20,000 units (0.02 USDC given 6 decimals). Payment is settled on-chain to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using the "exact" scheme.

The broader platform advertises four categories of APIs: 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 priced at $0.02 per request with no API keys, no rate limits, and no minimum commitments.

However, the specific functionality behind `/api/v1/carts/27` is unclear — the endpoint path suggests a cart resource rather than one of the documented API categories. Documentation pages (/docs, /api, /pricing, /README) all returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation available for any endpoint. The x402 challenge is live and well-formed, confirming the endpoint is operational, but what it actually returns upon successful payment is unknown.

Capabilities

x402-payment-gatedusdc-base-networkpay-per-requestno-api-keyjson-responseon-chain-settlement

Use cases

  • —Programmatic access to pay-per-call endpoints without traditional API key management
  • —Agent-driven API consumption with on-chain USDC micropayments on Base
  • —Exploring x402 protocol integration for automated machine-to-machine payments

Fit

Best for

  • —Developers experimenting with x402 payment protocol
  • —Agents that can settle USDC payments on Base L2
  • —Use cases requiring keyless, pay-as-you-go API access

Not for

  • —Production workloads requiring documented, stable API contracts
  • —Users who need detailed request/response schemas before integrating
  • —Anyone without a Base-compatible wallet or USDC balance

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/carts/27 \
  -H "Content-Type: application/json"
# Returns 402 with x402 payment 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/carts/27",
      "description": "Premium API Access",
      "maxAmountRequired": "20000",
      "maxTimeoutSeconds": 300
    }
  ],
  "x402Version": 1
}

Endpoint

URLhttps://lowpaymentfee.com/api/v1/carts/27
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.35/ 1.00

The x402 challenge is live and well-formed, confirming the endpoint exists and accepts USDC on Base. However, there is no OpenAPI schema, no documentation beyond a wallet-connect prompt, no request/response examples, and the specific purpose of /api/v1/carts/27 is ambiguous. The platform lists many endpoints but provides no detail on any of them.

Warnings

  • —No documentation available — all doc pages return only 'Connect wallet' with no content
  • —The endpoint path /api/v1/carts/27 does not match any of the documented API categories on the homepage
  • —No OpenAPI or schema describing request parameters or response format
  • —Actual functionality behind this endpoint is unknown without making a paid request
  • —No way to verify what data or service is delivered after payment

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-18 19:51:19Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-23

Agent access

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