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 marketplace that offers a broad set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. 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/183` is listed as "Premium API Access" and accepts POST requests settled via the x402 exact-payment scheme.
The platform advertises categories including 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). All endpoints appear to follow the same $0.02 USDC pricing model.
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 from the crawled material. The x402 challenge confirms the endpoint is live and accepts POST with a maxAmountRequired of 20000 base units (USDC with 6 decimals = $0.02), paying to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 on Base.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time finance and crypto market data on a per-request payment basis
- —Running data analytics queries and exporting reports via pay-as-you-go USDC micropayments
- —Using utility services like geocoding, validation, and conversion without subscriptions
Fit
Best for
- —Developers who want instant API access without signup or API keys
- —Agents and bots that can settle x402 payments in USDC on Base
- —Low-volume or sporadic usage where per-call pricing is more economical than subscriptions
Not for
- —High-volume production workloads where $0.02/request adds up quickly
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs
- —Developers not set up for crypto payments on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/183 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but documentation is essentially nonexistent — every doc page just shows 'Connect wallet'. No OpenAPI spec, no request/response schemas, no examples. The specific endpoint '/api/v1/transactions/183' has no description beyond its title. This is effectively a stub listing.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all return only 'Connect wallet' with no usable content
- —No OpenAPI or schema documentation available for any endpoint
- —No request or response examples are documented — input/output formats are unknown
- —The specific endpoint /api/v1/transactions/183 ('Premium API Access') is not listed among the advertised API categories on the homepage, making its purpose unclear
- —Cannot verify what data or functionality this specific endpoint actually provides
Citations
- —All endpoints cost $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 in USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/183
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com
- —Payment address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/transactions/183