Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints across data analytics, AI/ML inference, finance/crypto, and utility services. All endpoints are pay-per-request using USDC on the Base network, settled via the x402 protocol. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an X-PAYMENT header with each request.
The specific endpoint at `/api/v1/charges/20` is listed as "Premium API Access" and charges a maximum of 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals) per call. 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 utilities (geocoding, validation, conversion, generation). All listed endpoints share the same $0.02 per-request pricing.
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 documentation for any endpoint. The x402 challenge is live and well-formed, confirming the endpoint accepts POST requests and settles payments to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.
Capabilities
Use cases
- —Agent-driven data retrieval without managing API keys or subscriptions
- —On-demand AI inference (sentiment, summarization, classification, embeddings) paid per call
- —Fetching real-time crypto prices, gas estimates, and exchange rates via micropayments
- —Geocoding and data validation as utility microservices
Fit
Best for
- —AI agents that need keyless, pay-per-use API access
- —Developers prototyping with low-commitment, no-signup endpoints
- —Crypto-native applications already operating on Base network
Not for
- —High-volume production workloads needing guaranteed SLAs and detailed documentation
- —Users without USDC on Base network or unfamiliar with x402 payment protocol
- —Applications requiring well-documented request/response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/20 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages return only a wallet-connect prompt. The actual functionality behind the endpoints is unverifiable from available material.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or JSON schema describing request/response formats for any endpoint
- —Actual functionality behind listed endpoints (AI, analytics, finance, etc.) cannot be verified from crawl data
- —The specific endpoint /api/v1/charges/20 labeled 'Premium API Access' has no description of what it actually returns
Citations
- —All endpoints priced at $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 of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/20
- —USDC asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/charges/20
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com