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 catalog of pay-per-request endpoints across four categories: 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 are priced at $0.02 per request, payable in USDC on the Base network via the x402 protocol.
The specific endpoint `/api/v1/inbox/96` is listed as "Premium API Access" and 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. Payment is made via the `exact` scheme with a 300-second timeout. No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
Note that the specific functionality behind the `/api/v1/inbox/96` path is not documented on the site's landing page, which lists other named endpoints but not this one. The crawled /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no additional documentation. Without an OpenAPI spec or detailed docs, the exact request/response schema for this endpoint is unknown.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data like token quotes, gas estimates, and exchange rates on a per-call basis
- —Running geocoding, validation, or data conversion tasks with instant crypto-settled micropayments
- —Exporting analytics data or generating insights reports via pay-as-you-go endpoints
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost micropayment-gated endpoints without subscriptions
Not for
- —Users who need high-volume bulk pricing or enterprise SLAs
- —Callers without USDC on the Base network or x402-compatible payment infrastructure
- —Applications requiring detailed API documentation or guaranteed uptime guarantees
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/96 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no documentation for this specific path (/api/v1/inbox/96), no request/response schema, and the crawled pages beyond the landing page returned only wallet-connect prompts. The actual functionality of this endpoint is unknown.
Warnings
- —The specific endpoint /api/v1/inbox/96 is not listed among the named endpoints on the landing page — its purpose is unclear.
- —No OpenAPI spec, request schema, or response schema is available for any endpoint.
- —The /api, /pricing, and /README pages returned no useful content (only 'Connect wallet').
- —The broad catalog of endpoints listed on the homepage could not be individually verified.
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/inbox/96 specifies maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with exact scheme.https://lowpaymentfee.com/api/v1/inbox/96
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com