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 at `/api/v1/inbox/74` 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 or accounts are required — callers authenticate by attaching an x402 payment header with each request.
The 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 with no rate limits or minimum commitments.
Note that the specific endpoint being listed here (`/api/v1/inbox/74`) does not clearly map to any of the named API categories on the landing page. Its purpose is described only as "Premium API Access" with no further documentation on request/response format. The platform's docs, pricing, and README pages all require a wallet connection and do not expose additional technical detail. Treat this endpoint with caution until more documentation becomes available.
Capabilities
Use cases
- —Programmatic access to a generic premium API endpoint via x402 micropayment
- —Agent-driven workflows that need keyless, per-call API access settled on-chain
- —Testing x402 payment flows against a live endpoint on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —AI agents that need frictionless pay-per-call API access without credentials
- —Low-volume consumers who prefer per-request pricing over subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-throughput production workloads requiring well-documented schemas and error handling
- —Anyone who cannot pay in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/74 \
-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 documentation on what /api/v1/inbox/74 actually does, no request/response schema, and the docs/pricing/README pages are gated behind wallet connection. The endpoint name 'Premium API Access' is generic and uninformative.
Warnings
- —The endpoint path /api/v1/inbox/74 does not match any of the documented API categories on the landing page — its actual functionality is unknown.
- —No request or response schema is available; callers cannot know what to send or what to expect back.
- —Documentation pages (pricing, README, /api) are all behind a wallet-connect gate and returned no useful content.
- —This listing is effectively a stub due to lack of technical documentation.
Citations
- —The endpoint returns a 402 challenge requesting USDC payment on Base network with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/inbox/74
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/inbox/74
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com