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 set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/199` is listed as "Premium API Access" and carries a maxAmountRequired of 20,000 base units of USDC (0.02 USDC = $0.02), consistent with the site-wide pricing. The x402 challenge was captured live (version 1, scheme "exact", asset 0x8335…2913 which is USDC on Base). Payment is sent to address 0x1A2B…85F3 with a 300-second timeout.
The broader platform advertises endpoints in four categories: Data & Analytics (metrics, reports, 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). However, documentation is extremely thin — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There are no OpenAPI specs, request/response schemas, or usage examples available from the crawl. The actual behavior and response format of this specific transactions endpoint is unknown.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto gas estimates, token quotes, or exchange rates via micropayment
- —Running geocoding or data validation calls with per-request billing and no subscription
Fit
Best for
- —AI agents that need keyless, pay-per-call access to diverse API endpoints
- —Developers prototyping with low-commitment, no-subscription API access
- —Web3-native applications already operating on Base network with USDC
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/199 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The /docs, /pricing, /api, and /README pages are all empty beyond a wallet-connect prompt. The purpose of this specific '/transactions/199' endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —No API documentation available — all doc pages render only 'Connect wallet'
- —No OpenAPI or JSON schema describing request/response formats
- —The specific purpose and expected input/output of /api/v1/transactions/199 is undocumented
- —No information on uptime, SLAs, or rate limits beyond marketing claims of 'no rate limits'
- —Platform appears to be a demonstration or early-stage project with minimal operational detail
Citations
- —All endpoints priced at $0.02/request with no API keys, no rate limits, on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/199
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com