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/inbox/61` is listed as "Premium API Access" and costs up to $0.02 per request (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or subscriptions are required — callers simply attach an x402 payment header to each request.
The wider platform advertises four endpoint 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 listed endpoints share the same $0.02/request pricing.
Note that the specific functionality behind `/api/v1/inbox/61` is not documented beyond the generic "Premium API Access" label. There is no OpenAPI schema, no request/response examples, and the crawled docs pages (pricing, README, API) all resolve to a minimal "Connect wallet" prompt with no additional detail. Prospective callers should be aware that the actual behavior of this endpoint is unclear from available documentation.
Capabilities
Use cases
- —Programmatic access to premium API services without subscription or API key management
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers exploring x402 payment-gated APIs
- —AI agents that need frictionless pay-per-call access without credentials
- —Low-volume or sporadic API consumers who want no commitments
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/61 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no documentation explaining what /api/v1/inbox/61 actually does. The "Premium API Access" label is entirely generic. This is effectively a stub listing.
Warnings
- —No documentation exists for the specific endpoint /api/v1/inbox/61 — its actual functionality is unknown.
- —No OpenAPI or JSON schema is provided for request or response formats.
- —The crawled /pricing, /README, and /api pages all returned only a 'Connect wallet' prompt with no useful content.
- —The 'inbox' path segment suggests this may be a mailbox or messaging endpoint, but this is speculative.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x8335…) on Base network.https://lowpaymentfee.com/api/v1/inbox/61
- —All listed 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 platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com