Pay-per-call API platform on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every call costs $0.02 in USDC on the Base network, settled via the x402 payment protocol. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an X-PAYMENT header with a valid x402 payment proof to each request.
The specific endpoint `/api/v1/wire/105` 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 HTTP POST and returns application/json.
The broader platform advertises four 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 are priced at $0.02 per request. Documentation beyond the landing page is sparse — the /docs, /pricing, /api, and /README pages all appear to require a wallet connection and returned no substantive content during crawl.
Capabilities
Use cases
- —Agent-driven data retrieval without managing API keys or subscriptions
- —On-demand AI inference (sentiment, summarization, classification, embeddings) paid per call
- —Fetching real-time crypto prices, gas estimates, or exchange rates with micropayments
- —Geocoding or data conversion utilities billed per request via x402
Fit
Best for
- —AI agents that need frictionless, keyless API access with per-call billing
- —Developers prototyping integrations without committing to subscriptions
- —Low-volume or bursty workloads where pay-per-use is more economical than flat-rate plans
Not for
- —High-volume production workloads where per-call costs add up quickly
- —Users who need detailed API documentation or SDKs (docs are currently very sparse)
- —Callers who cannot settle payments in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/wire/105 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/wire/105",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-proof>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no response examples, and the documentation pages are all gated behind wallet connection with no crawlable content. The actual functionality behind '/api/v1/wire/105' (labeled only 'Premium API Access') is unclear — it doesn't map to any of the named endpoints on the landing page. This is effectively a stub listing.
Warnings
- —The endpoint path /api/v1/wire/105 does not match any of the named API endpoints listed on the landing page; its actual functionality is unknown.
- —All documentation pages (/docs, /pricing, /api, /README) returned no content beyond 'Connect wallet' — no usable docs are available.
- —No OpenAPI spec, no response schema, and no example responses were found.
- —The breadth of advertised APIs (16+ endpoints across 4 categories) could not be independently verified beyond the landing page listing.
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/wire/105 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.https://lowpaymentfee.com/api/v1/wire/105
- —The platform advertises endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com