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 endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network via the x402 payment protocol. No API keys, accounts, or rate limits are required — callers simply attach an X-PAYMENT header with a valid payment proof to access any endpoint.
The specific endpoint at `/api/v1/transactions/48` is listed as "Premium API Access" and returns `application/json`. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and is discoverable.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 flat rate. Documentation pages beyond the landing page were largely empty (showing only a "Connect wallet" prompt), so detailed request/response schemas for individual endpoints are not available.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes, gas estimates, or exchange rates via a single paid HTTP call
- —Geocoding or data validation as a utility microservice with no subscription commitment
- —Exporting analytics data or generating reports on a per-request billing basis
Fit
Best for
- —AI agents that need diverse utility endpoints behind a single payment protocol
- —Developers who want zero-signup, pay-as-you-go API access on Base
- —Applications requiring low-cost micropayment-settled API calls ($0.02 each)
Not for
- —High-volume batch processing where per-request pricing becomes expensive
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs
- —Callers without USDC on Base or an x402-compatible payment client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/48 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages beyond the landing page are empty stubs. The specific purpose of /api/v1/transactions/48 ('Premium API Access') is vague and undocumented. This is effectively a stub listing.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all return only a 'Connect wallet' prompt with no actual content
- —No OpenAPI or schema available for any endpoint
- —The specific endpoint /api/v1/transactions/48 has a generic 'Premium API Access' description with no details on what it actually returns
- —The breadth of advertised capabilities (AI, finance, geo, etc.) cannot be verified from available material
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —x402 challenge shows maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/48
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com