Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that hosts a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and general utility services. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network via the x402 payment protocol. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/inbox/45` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) on Base. The 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 endpoints appear to follow the same pricing and payment model.
Documentation beyond the landing page is sparse — the /api, /pricing, and /README pages all resolve to a minimal "Connect wallet" prompt with no further technical detail. No OpenAPI schema, request/response examples, or detailed endpoint documentation were found during the crawl. The purpose of the `/api/v1/inbox/45` path specifically is unclear; it does not correspond to any of the named endpoints listed on the homepage.
Capabilities
Use cases
- —Querying real-time financial data (prices, exchange rates, gas estimates) with per-call USDC payments
- —Running AI inference tasks (sentiment analysis, summarization, classification, embeddings) without API key management
- —Accessing utility services like geocoding and data validation on a pay-as-you-go basis
- —Exporting analytics data and generating insights via metered API calls
Fit
Best for
- —Developers who want keyless, pay-per-use API access settled on-chain
- —AI agents that can autonomously pay for API calls via x402
- —Projects needing low-friction access to multiple service categories without subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads that need guaranteed SLAs and rate-limit transparency
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/45 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, and the landing page lists available API categories with pricing. However, there is no OpenAPI schema, no request/response examples, no documentation beyond the homepage, and the specific /api/v1/inbox/45 path does not match any named endpoint. The crawled /api, /pricing, and /README pages are empty stubs.
Warnings
- —The path /api/v1/inbox/45 does not correspond to any of the named endpoints listed on the homepage — its specific function is unknown.
- —No API documentation, OpenAPI spec, or request/response examples are available.
- —The /api, /pricing, and /README pages returned only a 'Connect wallet' prompt with no content.
- —The platform's actual service delivery behind these endpoints cannot be verified from available crawl data.
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 platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/inbox/45 requests up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.https://lowpaymentfee.com/api/v1/inbox/45