Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/payments/251` is labeled "Premium API Access" and charges up to $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys or accounts are required — callers authenticate and pay via the x402 protocol's `X-PAYMENT` header.
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 utilities (geocoding, validation, conversion, generation). All listed endpoints are priced at $0.02 per request with no rate limits or minimum commitments.
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/payments/251` endpoint specifically returns. The x402 challenge confirms the endpoint is live and accepts POST requests, but the actual functionality behind "Premium API Access" is unclear from available materials.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key signup
- —Fetching real-time financial data like token quotes, gas estimates, and exchange rates on a per-call basis
- —Running data analytics queries and exporting data with instant crypto-settled micropayments
- —Using utility services like geocoding, validation, and conversion without rate limits
Fit
Best for
- —Agents or applications that need instant, keyless API access via crypto micropayments
- —Developers who want to avoid subscription commitments and pay only per request
- —Web3-native workflows that already hold USDC on Base
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Developers without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/251 \
-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 effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and the specific functionality of the /api/v1/payments/251 endpoint is undescribed beyond its title. 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 functionality of /api/v1/payments/251 ('Premium API Access') is not described anywhere — it is unclear what data or service it returns
- —No request or response examples are available
- —The broad catalog of endpoints (AI, finance, data, utils) is listed on the homepage but none have been individually verified as live or functional
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/251
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/251