Pay-per-call API platform on Base via x402 — $0.02/request for data, AI, finance, and utility endpoints.
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 and settle in USDC on the Base network.
The specific endpoint at `/api/v1/charges/212` is listed as "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 endpoint accepts HTTP POST requests and returns application/json.
Documentation is extremely sparse. The crawled /docs, /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the "Premium API Access" endpoint actually returns. The landing page lists many endpoints but provides no detail on input parameters or response formats for any of them. Without documentation, it is unclear what data or functionality this specific endpoint provides.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven API consumption without API keys or subscriptions
- —Pay-as-you-go access to analytics, AI inference, finance data, or utility services
Fit
Best for
- —Developers wanting keyless, pay-per-use API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Users without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/212 \
-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 pricing and payment details. However, there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The purpose of the specific /api/v1/charges/212 'Premium API Access' endpoint is entirely unclear. The docs, pricing, and README pages are all empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all return only a 'Connect wallet' prompt with no content.
- —No OpenAPI or schema definition for any endpoint.
- —The specific purpose and expected input/output of /api/v1/charges/212 ('Premium API Access') is undocumented and unclear.
- —The landing page lists ~16 endpoints but none have documented request/response formats.
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02.https://lowpaymentfee.com/api/v1/charges/212
- —The endpoint is described as 'Premium API Access' and accepts HTTP POST returning application/json.https://lowpaymentfee.com/api/v1/charges/212
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com