Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
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 via the x402 protocol. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an X-PAYMENT header with a valid x402 payment proof to access any endpoint.
The specific endpoint at `/api/v1/payments/343` is listed as "Premium API Access" and accepts POST requests. The x402 challenge indicates a maximum required amount of 20,000 base units of USDC (contract 0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimal places. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, 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 content.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without managing API keys or subscriptions
- —Fetching real-time crypto token quotes, gas estimates, and exchange rates via micropayment
- —Running geocoding, validation, or data conversion utilities on a per-call basis
- —Exporting analytics data or generating insights reports with pay-as-you-go pricing
Fit
Best for
- —Agents or bots that need frictionless, keyless API access paid per call
- —Developers prototyping with multiple API categories without upfront commitments
- —Web3-native workflows that can settle USDC payments on Base
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/343 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of this specific '/payments/343' endpoint is unclear beyond the generic 'Premium API Access' label. Effectively a stub listing.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all return only 'Connect wallet' with no technical content
- —No OpenAPI or schema available — request and response formats are unknown
- —The specific purpose of /api/v1/payments/343 ('Premium API Access') is not documented; it is unclear how it differs from other endpoints
- —No examples of successful responses are available from any source
Citations
- —Platform offers endpoints at $0.02/request with no API keys, no rate limits, and payment on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/payments/343
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com