Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no subscriptions required. The specific endpoint at `/api/v1/transactions/17` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (0x8335…0913 on Base), which equals $0.02 given USDC's 6 decimals.
The platform advertises four categories of APIs: 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 (geocoding, validation, conversion, generation). All endpoints follow the same $0.02 flat pricing model.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/transactions/17` endpoint specifically returns. The x402 challenge confirms the endpoint is live and accepts POST requests, but the actual payload format and response structure are unknown.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data like token quotes, exchange rates, and gas estimates on a per-call basis
- —Running data analytics queries and exporting data with micropayment-based access control
- —Using utility services like geocoding and validation without subscriptions
Fit
Best for
- —Agents or bots that need stateless, pay-per-call API access without credentials
- —Developers prototyping with multiple API categories at minimal cost
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where per-request pricing may add up quickly
- —Users who need detailed API documentation, schemas, or SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/17 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is no OpenAPI schema, no documentation beyond a landing page listing, no request/response examples, and no explanation of what the /api/v1/transactions/17 endpoint actually does. The docs pages are empty wallet-connect stubs.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or JSON schema describing request/response formats for any endpoint
- —The specific endpoint /api/v1/transactions/17 ('Premium API Access') has no description of its purpose or expected input/output
- —Cannot verify that the advertised AI, finance, or utility endpoints actually function as described
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/transactions/17 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/17
- —Platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs