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 commitments required. The x402 protocol handles payment inline: callers attach a payment header to each HTTP request and receive the response immediately.
The specific endpoint at `/api/v1/transfers/23` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this equals $0.02 per call — consistent with the site's advertised flat pricing. The endpoint accepts POST requests and returns `application/json`.
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 export. Documentation pages were largely empty (showing only a "Connect wallet" prompt), so detailed request/response schemas for individual endpoints are not available. The platform settles payments to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 on Base.
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 overhead
- —Exporting analytics data or generating reports on a per-request payment basis
Fit
Best for
- —AI agents that need keyless, pay-per-use access to diverse utility endpoints
- —Developers wanting to avoid subscription commitments for low-volume API usage
- —x402-compatible clients on the Base network looking for cheap USDC-settled calls
Not for
- —High-volume production workloads where subscription pricing would be cheaper
- —Users who need detailed API documentation or guaranteed SLAs
- —Callers who cannot settle payments in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/23 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation pages are essentially empty, there is no OpenAPI schema, no request/response examples, and the specific purpose of /api/v1/transfers/23 ("Premium API Access") is undocumented. The platform lists many endpoints but provides no detail on inputs or outputs for any of them.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only a 'Connect wallet' prompt with no actual content.
- —No OpenAPI or schema available — request and response formats for all endpoints are unknown.
- —The specific endpoint /api/v1/transfers/23 has a generic 'Premium API Access' label with no description of what it actually does or returns.
- —The platform lists many endpoint categories (AI, finance, analytics, etc.) but none have documented schemas or example payloads.
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/transfers/23 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.https://lowpaymentfee.com/api/v1/transfers/23
- —Platform offers endpoints for analytics, AI/ML (sentiment, summarization, classification, embeddings), finance (prices, rates, quotes, gas), and utilities (geocode, validate, convert, generate).https://lowpaymentfee.com