Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint `/api/v1/keys/86` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or subscriptions are required — each request is paid individually via the x402 payment protocol.
The 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 listed endpoints share the same $0.02 per-request pricing.
The specific functionality behind the `/api/v1/keys/86` endpoint is unclear from the available documentation — it is labeled generically as "Premium API Access" and does not appear in the main catalog of named endpoints. There is no OpenAPI schema, no request/response examples, and the ancillary pages (pricing, README, /api) returned only a wallet-connect prompt with no additional documentation. Agents should treat this endpoint with caution until its actual behavior is clarified.
Capabilities
Use cases
- —Paying per-request for API access without managing API keys or subscriptions
- —Programmatic agent access to utility or data endpoints settled on-chain
- —Testing x402 payment flows against a live endpoint
Fit
Best for
- —Developers or agents wanting zero-commitment, per-call API access
- —x402 protocol experimentation and integration testing
- —Scenarios where traditional API key management is undesirable
Not for
- —High-volume use cases where per-call pricing becomes expensive compared to subscription plans
- —Users who need detailed API documentation, schemas, or SLAs before integrating
Quick start
# The endpoint requires an x402 payment header (USDC on Base).
# 1. POST to the endpoint without payment to receive the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/keys/86
# 2. Parse the 402 response, construct an X-PAYMENT header with a signed USDC transfer, and retry.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no request/response examples, and no documentation explaining what `/api/v1/keys/86` actually returns. The endpoint name 'Premium API Access' is generic and doesn't match any of the named endpoints in the site catalog. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The endpoint '/api/v1/keys/86' does not appear in the site's published API catalog — its actual functionality is unknown
- —Ancillary pages (/pricing, /README, /api) returned only a wallet-connect prompt with no useful content
- —No request or response examples are available to verify what data this endpoint provides
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x8335…) on Base networkhttps://lowpaymentfee.com/api/v1/keys/86
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com