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 variety of endpoints across 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/111` 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 at /docs, /pricing, and /api but currently show only a "Connect wallet" prompt with no substantive content, so the actual request/response schemas for individual endpoints are unknown.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification) without API key management
- —Fetching real-time crypto token quotes and gas estimates programmatically
- —Running geocoding or data validation as a utility microservice with per-call billing
- —Exporting analytics data or generating insights reports on demand
Fit
Best for
- —AI agents that need simple pay-per-call access without signup or API keys
- —Developers prototyping with low-cost, no-commitment API access on Base
- —Web3-native applications that can settle micropayments in USDC
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation and guaranteed SLAs before integrating
- —Applications requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/111 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation pages are empty (showing only 'Connect wallet'), there is no OpenAPI spec, and no request/response schemas or examples are available for any endpoint. The specific purpose of /api/v1/transactions/111 beyond 'Premium API Access' is unclear.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) all return only 'Connect wallet' with no actual content
- —No OpenAPI or schema documentation available for any endpoint
- —The specific functionality of /api/v1/transactions/111 is undocumented — 'Premium API Access' is vague
- —Request and response body formats are entirely unknown
Citations
- —The endpoint returns a 402 challenge requesting 20,000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/111
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/111
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com