Pay-per-call API platform on Base via x402 — data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a collection of endpoints spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are paid per-request using USDC on the Base network via the x402 protocol, with no API keys, no rate limits, and no minimum commitments required.
The specific endpoint at `/api/v1/charges/372` is listed as "Premium API Access" and accepts POST requests. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The platform advertises a uniform $0.02/request pricing across all its endpoints.
The broader platform lists endpoints for metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation. However, documentation beyond the landing page is essentially empty (all doc/pricing/API pages only show a "Connect wallet" prompt), so the actual behavior, request schemas, and response formats of these endpoints are undocumented. The endpoint is confirmed live via a valid 402 challenge.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time financial data such as token quotes, exchange rates, or gas estimates via micropayments
- —Running data analytics queries or exporting data with per-request USDC payments on Base
- —Geocoding, validation, or conversion utilities paid per call with no subscription
Fit
Best for
- —AI agents needing key-free, pay-as-you-go access to diverse API endpoints
- —Developers who want to avoid subscription commitments for low-volume API usage
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where $0.02/request adds up significantly compared to subscription plans
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/372 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge and clear pricing ($0.02 USDC on Base). However, documentation is essentially nonexistent — all doc, pricing, and API pages render only a 'Connect wallet' prompt. There is no OpenAPI schema, no request/response examples, and no description of what the 'Premium API Access' endpoint actually returns. The listing is largely a stub.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) are all empty beyond a 'Connect wallet' prompt — no usable API docs exist.
- —No OpenAPI or schema available; request and response formats for this endpoint are unknown.
- —The specific endpoint /api/v1/charges/372 is labeled 'Premium API Access' but its actual functionality is undocumented — it is unclear what data or service it provides.
- —The platform lists many endpoints (AI, finance, data, utils) but none have documented schemas or example payloads.
Citations
- —Uniform pricing of $0.02 per request across all endpoints, no API keys, no rate limitshttps://lowpaymentfee.com
- —Endpoint accepts USDC on Base network with maxAmountRequired of 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/charges/372
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/372
- —Platform lists endpoints for analytics, AI, finance, and utility categorieshttps://lowpaymentfee.com