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. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no commitments required. The specific endpoint at `/api/v1/customers/75` is labeled "Premium API Access" and returns JSON via POST.
The platform advertises four main 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 endpoints follow the x402 payment protocol, where callers attach an X-PAYMENT header with a signed USDC payment on Base to authenticate and pay in a single step.
The probed endpoint (`/api/v1/customers/75`) returned a valid 402 challenge with a maxAmountRequired of 20000 base units of USDC (0x8335… on Base, 6 decimals), which equals $0.02. The payment is settled to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. Documentation pages beyond the landing page were essentially empty (showing only "Connect wallet"), so the actual response schemas and detailed API behavior are unknown.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates
- —Running data analytics queries and exporting reports on a per-request payment basis
- —Using utility services like geocoding and data validation with instant crypto micropayments
- —Building agent workflows that pay per call via x402 on Base
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost micropayment-gated endpoints without rate limits
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —Applications requiring fiat-only payment rails with no crypto involvement
- —High-volume batch workloads where per-request pricing may add up
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/customers/75 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond the landing page, no example request/response bodies, and the specific purpose of `/api/v1/customers/75` is unclear. The docs, pricing, and README pages all returned only 'Connect wallet' with no useful content.
Warnings
- —Documentation pages (/docs, /pricing, /README, /api) are effectively empty — only show 'Connect wallet'
- —No OpenAPI or schema available; response format for this endpoint is unknown
- —The endpoint path '/api/v1/customers/75' suggests customer-specific data but its actual function is undocumented
- —The broad catalog of advertised endpoints (AI, finance, analytics, utils) could not be independently verified beyond the landing page listing
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/customers/75 requires 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with a 300-second timeouthttps://lowpaymentfee.com/api/v1/customers/75