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 collection 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 upfront commitments. The specific endpoint at `/api/v1/transactions/237` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02, since USDC uses 6 decimals) on Base.
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 utilities (geocoding, validation, conversion, generation). All endpoints follow the same $0.02 per-request pricing model.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The x402 challenge is live and well-formed, confirming the endpoint accepts POST requests and settles payments via USDC on Base to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.
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 per-request USDC micropayments
- —Using utility services like geocoding and validation without subscriptions
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments in USDC on Base
- —Projects needing diverse API capabilities without managing API keys or rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/237 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint works and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages render only 'Connect wallet' with no useful content. The specific purpose of the /api/v1/transactions/237 endpoint beyond 'Premium API Access' is unknown.
Warnings
- —No OpenAPI schema or detailed API documentation available — all doc pages show only 'Connect wallet'
- —The specific functionality of /api/v1/transactions/237 ('Premium API Access') is unclear; it does not match any of the advertised endpoint paths
- —No request or response examples are available for any endpoint
- —The breadth of advertised capabilities (AI, finance, analytics, utilities) is unverifiable without documentation
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 requests maxAmountRequired of 20000 base units of USDC (USD Coin) on Basehttps://lowpaymentfee.com/api/v1/transactions/237
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages all render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs