Pay-per-request API platform on Base via x402 — data, AI, finance, and utility endpoints at $0.02/call.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints across four 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, paid in USDC on the Base network.
The specific endpoint at `/api/v1/charges/243` is labeled "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02. Payment is made via the x402 exact scheme — no API keys, subscriptions, or rate limits are required. The platform advertises instant access with no minimums or commitments.
Documentation is extremely sparse. The docs, API, pricing, 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 detailed documentation for any endpoint. It is unclear what specific data or functionality the "Premium API Access" endpoint at `/api/v1/charges/243` returns, as it does not correspond to any of the named endpoints listed on the homepage. The endpoint is live and responds with a proper 402 challenge.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data such as token quotes, gas estimates, and exchange rates
- —Running data analytics queries and exporting data on a per-request payment basis
- —Using utility services like geocoding, validation, and conversion with instant crypto payment
Fit
Best for
- —Agents or developers who want zero-signup, pay-as-you-go API access
- —Crypto-native applications that can settle payments in USDC on Base
- —Low-volume or sporadic API consumers who don't want subscriptions
Not for
- —High-volume production workloads needing guaranteed SLAs and detailed documentation
- —Users without a Base-compatible wallet or USDC holdings
- —Developers requiring comprehensive OpenAPI specs and request/response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/243 \
-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 works. However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and the specific purpose of /api/v1/charges/243 ('Premium API Access') is unclear relative to the named endpoints on the homepage. Pricing is clear but everything else must be inferred.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only 'Connect wallet' with no actual content
- —No OpenAPI or schema available for any endpoint
- —The endpoint path /api/v1/charges/243 does not match any of the named API endpoints listed on the homepage — its specific functionality is unknown
- —No request or response examples are available anywhere in the crawled material
Citations
- —All endpoints are priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —Payment is in USDC on the Base network via x402 exact scheme with maxAmountRequired of 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/charges/243
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/243