Pay-per-call customer data API on Base via x402, settled in USDC at $0.02/request.
What it does
lowpaymentfee.com hosts a collection of pay-per-request APIs accessible via the x402 payment protocol on the Base network. This specific endpoint (`/api/v1/customers/4`) is listed as "Premium API Access" and returns JSON data when a valid x402 payment header is provided. Payment is settled in USDC (contract 0x8335…2913 on Base) with a maximum cost of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals).
The broader lowpaymentfee.com platform advertises endpoints across several 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 utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request with no API keys, no rate limits, and no minimum commitments.
Documentation is extremely sparse — the /docs, /pricing, /api, 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 description of what the `/api/v1/customers/4` endpoint actually returns. The endpoint is confirmed live (402 challenge captured), but the lack of documentation makes it difficult to know what data to send or expect back.
Capabilities
Use cases
- —Fetching customer or entity data on a per-request payment basis without needing API keys
- —Integrating pay-as-you-go data access into autonomous agents via x402
- —Demonstrating x402 payment protocol integration on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-per-call API access on Base
- —Low-volume or sporadic data retrieval where subscriptions are overkill
Not for
- —Production workloads requiring well-documented, schema-validated APIs
- —High-volume use cases where per-request pricing is inefficient
- —Users who need detailed documentation or support
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/customers/4 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty stubs showing only 'Connect wallet'. The purpose of /api/v1/customers/4 is not explained anywhere.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages are all empty stubs
- —No OpenAPI or request/response schema provided; unclear what this endpoint returns
- —The endpoint path '/api/v1/customers/4' suggests a specific resource but its contents are unknown
- —No robots.txt or agents.txt present
Citations
- —Endpoint returns 402 with x402 challenge advertising USDC on Base at maxAmountRequired 20000https://lowpaymentfee.com/api/v1/customers/4
- —All endpoints priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/customers/4
- —Documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no contenthttps://lowpaymentfee.com/docs