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/190` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 protocol — no API keys, accounts, or subscriptions are required; callers attach an X-PAYMENT header with a signed USDC payment 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. The platform claims no rate limits, no minimums, and instant access.
Important caveat: the specific `/api/v1/inbox/190` endpoint's purpose is unclear — it does not map to any of the named API categories on the landing page. Its description is simply "Premium API Access" with no further documentation, input schema, or example responses available. The crawled docs, pricing, and README pages all returned only a "Connect wallet" prompt with no additional content. Prospective callers should be aware that documentation is essentially absent for this particular endpoint.
Capabilities
Use cases
- —Programmatic access to a generic premium API endpoint via x402 micropayments
- —Agent-driven workflows that need keyless, pay-as-you-go API calls settled on Base
- —Testing x402 payment flows with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —AI agents that need frictionless, keyless API access
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Anyone needing well-documented, production-grade APIs with clear input/output schemas
- —Users who cannot pay in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/190 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge), but there is no documentation, no input/output schema, no examples, and the endpoint path (/api/v1/inbox/190) does not correspond to any documented API on the landing page. Effectively a stub listing with only pricing and protocol details available.
Warnings
- —The endpoint /api/v1/inbox/190 is not listed among the documented APIs on the landing page — its actual functionality is unknown.
- —No input schema, output schema, or example responses are available.
- —All documentation pages (pricing, README, /api) returned only a 'Connect wallet' prompt with no useful content.
- —The generic name 'Premium API Access' provides no indication of what the endpoint actually does.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/inbox/190
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/inbox/190
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform lists Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com