x402-payable API suite offering data, AI, finance, and utility endpoints on Base network via USDC micropayments.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/resource/3` is labeled "Premium API Access" and accepts POST requests, returning JSON responses. Payment is made in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) with a maximum amount of 20,000 units (likely 0.02 USDC given 6 decimals, consistent with the site's advertised $0.02/request pricing).
The broader platform advertises 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 (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments required.
However, the specific functionality of `/api/resource/3` is not documented — the endpoint path does not match any of the named endpoints on the landing page. Documentation pages (/docs, /pricing, /README) returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation available for this or any other endpoint on the platform.
Capabilities
Use cases
- —Accessing premium API resources via x402 micropayments without API key registration
- —Programmatic agent-driven API consumption with per-request USDC payments on Base
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-use API access on Base
- —Low-volume consumers who prefer micropayments over subscriptions
Not for
- —Users needing well-documented, production-grade APIs with clear schemas
- —High-volume use cases where $0.02/request adds up significantly
- —Anyone requiring detailed request/response documentation before integration
Quick start
# The endpoint requires an X-PAYMENT header with a valid x402 payment proof.
# Without payment, it returns a 402 challenge.
curl -X POST https://lowpaymentfee.com/api/resource/3 \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but the specific resource at /api/resource/3 has no documentation, no schema, no examples, and no description beyond the generic label 'Premium API Access'. Documentation pages are empty. The endpoint path doesn't correspond to any named API on the landing page, making its actual functionality unknown.
Warnings
- —The endpoint path /api/resource/3 does not match any documented API on the landing page — its actual functionality is unknown.
- —All documentation pages (/docs, /pricing, /README, /api) returned only a 'Connect wallet' prompt with no substantive content.
- —No OpenAPI schema, request format, or response examples are available for this or any endpoint on the platform.
- —The platform lists many endpoint categories (AI, finance, data, etc.) but none appear to correspond to this specific resource path.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, accepting USDC on Base network with maxAmountRequired of 20000https://lowpaymentfee.com/api/resource/3
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 and payTo address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/resource/3