x402basequality 0.35

Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.

Price
0.02 USDC / call
Protocol
x402
Verified
no

What it does

lowpaymentfee.com is an x402-enabled API marketplace that exposes a broad set of 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 endpoints are priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol — no API keys, no rate limits, and no upfront commitments.

The specific endpoint probed (`/api/v1/messages/192`) is described as "Premium API Access" and returned a live 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. Payment is made via the x402 exact scheme to the specified payTo address. The endpoint accepts HTTP POST and returns `application/json`.

Documentation is minimal — the landing page lists available endpoints and pricing but provides no request/response schemas, parameter descriptions, or usage examples. The `/api`, `/pricing`, and `/README` pages all resolve to a "Connect wallet" prompt with no additional content. Because of this, the actual behavior of `/api/v1/messages/192` (and most other endpoints) is unclear; the "Premium API Access" label is generic and does not describe what data or functionality is returned.

Capabilities

x402-paymentusdc-basepay-per-requestdata-analyticsai-inferencesentiment-analysistext-summarizationclassificationembeddingsfinance-datacrypto-quotesgas-estimatesgeocodingvalidationconversion

Use cases

  • Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without API key management
  • Fetching real-time crypto token quotes or gas estimates via a single paid HTTP call
  • Geocoding or data validation as a utility microservice with no subscription overhead

Fit

Best for

  • AI agents that need keyless, pay-per-call access to diverse utility endpoints
  • Developers prototyping with low-cost, no-commitment API access on Base
  • Web3-native applications that can settle USDC micropayments on Base

Not for

  • High-volume production workloads that need SLAs, rate-limit guarantees, or detailed documentation
  • Users who cannot transact in USDC on the Base network

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/messages/192 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-header>" \
  -d '{}'

Endpoint

Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.35/ 1.00

The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, no examples, and the purpose of /api/v1/messages/192 is entirely opaque. The landing page lists many endpoints but provides no detail on any of them.

Warnings

  • No API documentation, request schemas, or response examples are available for any endpoint.
  • The specific endpoint /api/v1/messages/192 is labeled only 'Premium API Access' with no description of what it actually does.
  • The /api, /pricing, and /README pages all return only a 'Connect wallet' prompt with no useful content.
  • Cannot verify what data or functionality any endpoint actually returns without making a paid request.

Citations

  • All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base network.
    https://lowpaymentfee.com
  • The 402 challenge for /api/v1/messages/192 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.
    https://lowpaymentfee.com/api/v1/messages/192
  • Available endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.
    https://lowpaymentfee.com

Provenance

Indexed fromx402_bazaar
Enriched2026-04-21 23:08:27Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-21
Last seen2026-04-22

Agent access