x402-gated premium API access on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall on the Base network. The site hosts a broad catalog of pay-per-call APIs spanning data & analytics, 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, settled in USDC on Base with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/charges/369` is labeled "Premium API Access" in the x402 challenge. The challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02. Payment is via the x402 exact scheme: callers attach an X-PAYMENT header with a signed payment to the payTo address. The response MIME type is application/json and the endpoint accepts HTTP POST.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material. It is unclear what specific data or functionality the `/api/v1/charges/369` endpoint returns, as the site's landing page lists many different API categories but does not map charge IDs to specific services.
Capabilities
Use cases
- —Programmatic access to paid API services without traditional API key registration
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Integrating pay-per-use data, AI, or finance endpoints into decentralized applications
Fit
Best for
- —Developers or agents who want zero-signup, pay-as-you-go API access
- —Users already holding USDC on Base who want frictionless micropayments
- —Prototyping or low-volume usage where per-call pricing is more economical than subscriptions
Not for
- —High-volume production workloads where subscription pricing would be cheaper
- —Users who need detailed API documentation, SDKs, or OpenAPI specs before integrating
- —Anyone without a Base-compatible wallet or USDC holdings
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/369 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The specific function of /api/v1/charges/369 is unknown. Effectively a stub listing.
Warnings
- —No OpenAPI spec or request/response schema available
- —Documentation pages return only 'Connect wallet' with no technical content
- —The specific functionality behind /api/v1/charges/369 is not documented — it is unclear what data or service it provides
- —No usage examples or error handling documentation found
Citations
- —The site lists APIs across data & analytics, AI & ML, finance & Web3, and infrastructure, all priced at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02 per request with no API keys, no rate limits, instant access, on Base networkhttps://lowpaymentfee.com
- —x402 challenge shows maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, payTo 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/charges/369