Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/inbox/117` 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, no subscriptions, and no rate limits. Callers attach an `X-PAYMENT` header with a valid payment proof and receive the response immediately.
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.
However, the specific functionality behind the `/api/v1/inbox/117` path is not documented beyond the generic label "Premium API Access." 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 particular endpoint is unclear from available documentation.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand, per-call payment for data or AI services
- —Integrating low-cost utility endpoints (geocoding, validation, conversion) into pipelines
Fit
Best for
- —Developers or agents wanting frictionless pay-per-use API access on Base
- —Use cases requiring no upfront commitment or rate-limit negotiation
- —Crypto-native applications that can sign USDC payments on Base
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Callers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/117 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge) and pricing is clear ($0.02 USDC on Base), but there is no documentation of what this specific endpoint does, no OpenAPI schema, no request/response examples, and the crawled pages beyond the homepage are empty. The listing is effectively a stub.
Warnings
- —The specific functionality of /api/v1/inbox/117 ('Premium API Access') is undocumented — it is unclear what data or service it provides.
- —No OpenAPI or JSON schema is available for request or response payloads.
- —Documentation pages (/api, /pricing, /README) returned only a 'Connect wallet' prompt with no useful content.
- —The platform lists many endpoint categories on its homepage but none have detailed docs visible without a wallet connection.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/inbox/117
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/inbox/117
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com