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 x402 payment protocol handles authentication: callers attach an X-PAYMENT header with a signed USDC payment, and the server fulfills the request.
The specific endpoint at `/api/v1/transactions/346` is listed as "Premium API Access" and returns `application/json`. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and is discoverable. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The platform also advertises AI endpoints (sentiment analysis, text summarization, classification, embeddings), finance endpoints (price feeds, exchange rates, token quotes, gas estimates), data endpoints (metrics, reports, export, insights), and utility endpoints (geocoding, validation, conversion, generation) — all at the same $0.02 price point. Documentation pages exist but appear to require wallet connection and contain no substantive content in the crawl.
Capabilities
Use cases
- —Accessing premium API data without traditional API key signup
- —Making one-off paid API calls from autonomous agents using USDC on Base
- —Integrating pay-as-you-go API access into Web3 applications
Fit
Best for
- —Developers who want instant API access without registration
- —AI agents that can settle payments via x402 on Base
- —Projects needing low-cost per-request pricing with no commitments
Not for
- —Users who need free or ad-supported API access
- —Applications requiring high-throughput bulk data at volume discounts
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/346 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-signed-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation content (all doc pages just show 'Connect wallet'), no request/response examples, and the specific purpose of '/api/v1/transactions/346' labeled 'Premium API Access' is entirely unclear — it doesn't match any of the advertised endpoint categories.
Warnings
- —The specific endpoint /api/v1/transactions/346 is not listed among the platform's advertised APIs; its actual functionality is unknown.
- —All documentation pages (docs, api, pricing, README) returned only 'Connect wallet' with no substantive content.
- —No OpenAPI spec, request schema, or response schema is available.
- —The purpose of 'Premium API Access' at a transactions path is ambiguous — it may be a generic or placeholder endpoint.
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge shows maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base network.https://lowpaymentfee.com/api/v1/transactions/346
- —The platform advertises endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilities.https://lowpaymentfee.com