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/ML inference (sentiment analysis, 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 minimum commitments.
The specific endpoint `/api/v1/charges/146` 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, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no examples available. It is unclear what specific data or functionality the "Premium API Access" endpoint returns, as the name is generic and the site provides no further detail beyond the landing page catalog listing.
Capabilities
Use cases
- —Programmatic access to a pay-per-call API without API key registration
- —Agent-driven workflows that need on-demand API access settled in USDC on Base
- —Testing x402 payment flows against a live, low-cost endpoint
Fit
Best for
- —Developers exploring x402 payment protocol integrations
- —AI agents that need keyless, pay-per-request API access
- —Low-cost experimentation with crypto-settled API calls
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Anyone requiring a specific, well-documented API capability (the endpoint's actual functionality is undocumented)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/146 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the endpoint name 'Premium API Access' is entirely generic with no indication of what it actually returns. Effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet' with no content.
- —No OpenAPI or request/response schema provided; it is unknown what data or functionality this endpoint returns.
- —The endpoint name 'Premium API Access' is generic and does not describe a specific capability.
- —The site lists many endpoints but none have detailed docs; actual functionality is unverifiable.
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/146
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The site offers APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs