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 catalog 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/263` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises endpoints in four categories: 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). Documentation pages exist but appear to require a wallet connection to view, so detailed request/response schemas for individual endpoints are not available from the crawl.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes, gas estimates, or exchange rates with per-call payment
- —Running geocoding, data validation, or format conversion as utility microservices
- —Exporting analytics data or generating insights reports on a pay-as-you-go basis
Fit
Best for
- —AI agents that need diverse utility endpoints behind a single payment protocol
- —Developers who want zero-signup, zero-rate-limit API access
- —Applications settling micropayments in USDC on Base L2
Not for
- —High-volume batch workloads where $0.02/request adds up significantly
- —Users who need detailed SLAs, uptime guarantees, or enterprise support
- —Callers who cannot settle payments in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/263 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint works and pricing is clear ($0.02 USDC on Base). However, documentation pages all resolve to a wallet-connect prompt with no actual content, there is no OpenAPI spec, and no request/response schemas or examples are available for any endpoint. The specific purpose of /api/v1/transactions/263 ('Premium API Access') is vague and undocumented.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only a 'Connect wallet' prompt — no actual documentation is publicly accessible.
- —No OpenAPI or schema definitions are available; request and response formats for all endpoints are unknown.
- —The specific function of /api/v1/transactions/263 ('Premium API Access') is unclear — it may be a generic or placeholder endpoint.
- —The platform lists many endpoint categories (AI, finance, analytics, infrastructure) but none have verifiable documentation confirming they actually function as described.
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 (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/263
- —Platform offers endpoints in Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages resolve to wallet-connect prompt onlyhttps://lowpaymentfee.com/docs