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, paid in USDC on the Base network with no API keys, rate limits, or subscriptions required. The specific endpoint at `/api/v1/transactions/178` is listed as "Premium API Access" and returns JSON.
The platform advertises four categories of APIs: 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 (geocoding, validation, conversion, generation). Each endpoint uses the x402 payment protocol, where callers attach a payment header with USDC on Base to authenticate and pay in a single step.
The probed endpoint (`/api/v1/transactions/178`) returned a valid 402 challenge with a `maxAmountRequired` of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base, 6 decimals), which equals $0.02. The endpoint accepts POST requests and returns `application/json`. Documentation beyond the landing page is essentially empty — the docs, API, pricing, and README pages all just show a "Connect wallet" prompt with no further content.
Capabilities
Use cases
- —Accessing analytics metrics and reports on a per-call basis without subscriptions
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with micropayments
- —Fetching real-time crypto prices, exchange rates, and gas estimates
- —Performing utility operations like geocoding, validation, and data conversion
Fit
Best for
- —Developers who want instant API access without signup or API keys
- —Agents and bots that can settle payments in USDC on Base
- —Low-volume or sporadic API usage where per-call pricing is more economical than subscriptions
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Developers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/178 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty stubs ('Connect wallet'). The specific purpose of '/api/v1/transactions/178' labeled 'Premium API Access' is unclear — it does not appear in the site's listed API catalog, making its actual functionality unknown.
Warnings
- —The specific endpoint /api/v1/transactions/178 is not listed among the site's advertised APIs; its actual functionality is unknown.
- —All documentation pages (docs, API, pricing, README) are empty — they only show 'Connect wallet' with no content.
- —No request or response schema is available; callers cannot know what to send or what to expect back.
- —The endpoint's description 'Premium API Access' is generic and does not describe what the endpoint actually does.
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —Payment in USDC on Base network via x402 protocolhttps://lowpaymentfee.com
- —Four API categories: Data & Analytics, AI & ML, Finance & Web3, Infrastructurehttps://lowpaymentfee.com
- —maxAmountRequired of 20000 base units USDC (= $0.02) confirmed via 402 challengehttps://lowpaymentfee.com/api/v1/transactions/178