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 variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 payment protocol allows agents and users to pay per call by attaching a payment header to each HTTP request.
The specific endpoint at `/api/v1/charges/324` 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 equates to $0.02 per request, consistent with the site's advertised pricing. The endpoint accepts POST requests and returns application/json responses.
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 generation — all at the same $0.02 price point. However, documentation pages (docs, pricing, README) returned only a "Connect wallet" prompt with no substantive content, so the actual request/response schemas for this and other endpoints remain undocumented.
Capabilities
Use cases
- —Agents making one-off paid API calls without needing API key registration
- —Programmatic access to utility or data endpoints with crypto micropayments
- —Testing x402 payment protocol integrations on Base network
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle x402 payments in USDC on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation and request/response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Users without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/324 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI spec, no documentation of request parameters or response schemas, and the docs/pricing/README pages are all empty (just 'Connect wallet'). The specific purpose of '/api/v1/charges/324' beyond 'Premium API Access' is unknown, making this effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages all return only 'Connect wallet' with no content.
- —The specific functionality of /api/v1/charges/324 ('Premium API Access') is not described anywhere; it is unclear what data or service it provides.
- —No request or response schema is documented for any endpoint on the platform.
- —The platform lists many endpoint categories (AI, finance, analytics, etc.) but none have documented input/output contracts.
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equating to $0.02https://lowpaymentfee.com/api/v1/charges/324
- —Endpoint described as 'Premium API Access' accepting POST with application/json mime typehttps://lowpaymentfee.com/api/v1/charges/324
- —Platform lists endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com