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 suite of endpoints across four 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 endpoints are priced at $0.02 per request, payable in USDC on the Base network via the x402 protocol.
The specific endpoint `/api/v1/inbox/147` is listed as "Premium API Access" and advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with no API keys, no rate limits, and no commitments required — callers simply attach an X-PAYMENT header to each POST request.
Documentation is minimal: the landing page lists available endpoints and pricing, but the /api, /pricing, and /README pages all resolve to a wallet-connect prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples. The purpose of the `/api/v1/inbox/147` path specifically (as opposed to the named category endpoints) is unclear — it may be a generic or catch-all premium endpoint, but this is not documented.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time finance data (prices, exchange rates, gas estimates) on a per-call basis
- —Running data analytics queries and exports with micropayments
- —Using utility services like geocoding and validation without subscriptions
Fit
Best for
- —Agents or bots that need low-friction, keyless API access
- —Developers prototyping with pay-as-you-go pricing on Base/USDC
- —Use cases requiring small, infrequent API calls without rate-limit concerns
Not for
- —High-volume production workloads needing SLAs or guaranteed uptime
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/147 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and the specific purpose of /api/v1/inbox/147 is undocumented. Effectively a stub listing.
Warnings
- —No OpenAPI spec or request/response schema available
- —The /api, /pricing, and /README pages return only a wallet-connect prompt with no documentation
- —The specific endpoint path /api/v1/inbox/147 ('Premium API Access') is not explained — its function relative to the named category endpoints is unclear
- —No examples of request bodies or response formats are provided anywhere
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —maxAmountRequired is 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/inbox/147
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com