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 utility services. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/charges/393` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, documentation is extremely sparse: the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available. It is unclear what specific functionality the `/api/v1/charges/393` endpoint provides beyond its generic "Premium API Access" label.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without account registration
- —Agent-driven API consumption with per-call USDC micropayments on Base
- —Accessing data, AI, finance, or utility services with no rate limits
Fit
Best for
- —Developers or agents wanting frictionless pay-per-use API access
- —Users who prefer crypto micropayments over subscription billing
- —Quick prototyping without API key management
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads where per-call pricing may add up
- —Users who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/393 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts payments. However, there is no documentation, no OpenAPI spec, no request/response schemas, and no examples. The specific functionality behind 'Premium API Access' at /api/v1/charges/393 is completely opaque. All non-homepage pages return only 'Connect wallet' with no content.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition for request or response payloads
- —The specific functionality of /api/v1/charges/393 ('Premium API Access') is undefined — it is unclear what data or service it returns
- —Cannot verify what the endpoint actually does without paying
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 with exact scheme and 300s timeouthttps://lowpaymentfee.com/api/v1/charges/393
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com