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 broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no upfront commitments. The specific endpoint at `/api/v1/transactions/73` is listed as "Premium API Access" and returns `application/json` via POST.
The platform advertises four main 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 utilities (geocoding, validation, conversion, generation). All endpoints appear to follow the same x402 payment flow — callers receive a 402 challenge with payment details, settle in USDC on Base, and then receive the API response.
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 description of what the `/api/v1/transactions/73` endpoint specifically returns. The x402 challenge confirms the endpoint is live and accepts USDC payments of up to 20,000 base units ($0.02) on Base.
Capabilities
Use cases
- —Accessing analytics metrics and reports on a per-call basis without subscription
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with per-request USDC payment
- —Fetching real-time crypto prices, gas estimates, and exchange rates
- —Geocoding, data validation, and format conversion utilities
Fit
Best for
- —Developers who want zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost micro-transactions for API calls
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads that benefit from bulk pricing or rate-limit guarantees
- —Developers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/73
# Returns 402 with x402 challenge; attach X-PAYMENT header with USDC payment proof on Base to access.Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but documentation is essentially nonexistent — all doc/API/pricing pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and no description of what the /api/v1/transactions/73 endpoint actually returns. The listing is largely a stub.
Warnings
- —Documentation pages (docs, API, pricing, README) all render only 'Connect wallet' with no usable content
- —No OpenAPI or JSON schema available for any endpoint
- —The specific purpose of /api/v1/transactions/73 ('Premium API Access') is undocumented — unclear what data it returns
- —No request body schema or response examples are available
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/transactions/73 specifies maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/73
- —Docs, API, pricing, and README pages render only 'Connect wallet'https://lowpaymentfee.com/docs