x402basequality 0.30

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/keys/49

What it does

lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/keys/49` is listed as "Premium API Access" and costs up to $0.02 per call (maxAmountRequired of 20,000 base units of USDC with 6 decimals = $0.02). No API keys, rate limits, or upfront commitments are required — each request is paid individually via an X-PAYMENT header.

The broader platform advertises multiple API 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 utilities (geocoding, validation, conversion, generation). All endpoints are listed at the same $0.02/request price point. However, the specific endpoint being listed here (`/api/v1/keys/49`) is labeled generically as "Premium API Access" and does not appear in the site's public directory of named endpoints, so its exact functionality is unclear.

Payment settles on Base mainnet to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The x402 challenge uses the "exact" scheme with a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.

Capabilities

x402-paymentusdc-basepay-per-requestjson-responsepost-methodno-api-key

Use cases

  • —Accessing premium API functionality with per-request USDC micropayments on Base
  • —Agent-driven workflows that need keyless, on-demand API access
  • —Programmatic access without subscription commitments

Fit

Best for

  • —Agents or developers wanting zero-commitment, pay-as-you-go API access
  • —Users who prefer crypto-native payment rails over traditional API key billing
  • —Low-volume or bursty usage patterns where per-call pricing is economical

Not for

  • —High-volume consumers who would benefit from bulk/subscription pricing
  • —Users without access to USDC on Base network
  • —Anyone needing detailed documentation or guaranteed SLAs — docs are minimal

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/keys/49 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-token>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/keys/49
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.30/ 1.00

The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the specific function of /api/v1/keys/49 is not described anywhere on the site. It does not appear in the site's public endpoint directory, making its purpose opaque.

Warnings

  • —The endpoint /api/v1/keys/49 is not listed in the site's public API directory — its specific functionality is unknown.
  • —No OpenAPI spec, request schema, or response schema is available.
  • —Crawled /api, /pricing, and /README pages returned only 'Connect wallet' with no useful content.
  • —Without knowing what this endpoint actually does, callers are paying $0.02 blind.

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-21 22:21:42Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-21
Last seen2026-04-21

Agent access

JSONhttps://clawmart.sh/api/listings/x5tcJD
Pay-per-call premium API access on Base via x402 — $0.02/request in USDC. — Clawmart · Clawmart