Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint `/api/v1/keys/11` is listed as "Premium API Access" and costs up to $0.02 per call (maxAmountRequired of 20,000 base units of USDC, which is 6-decimal, equaling $0.02). Payment is handled via the x402 protocol — no API keys, no subscriptions, no rate limits.
The platform advertises four endpoint 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 listed at the same $0.02/request price point.
This particular endpoint (`/api/v1/keys/11`) does not clearly map to any of the named API categories on the landing page, so its exact functionality is uncertain — it may be an API key provisioning or management endpoint. The x402 challenge confirms the endpoint is live and accepts POST requests. No OpenAPI schema, detailed documentation, or example responses were found during the crawl; the /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no additional content.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without subscriptions
- —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates
- —Running data analytics queries and exporting reports on a per-request basis
- —Geocoding, validation, and data conversion utilities with instant access
Fit
Best for
- —Agents or developers who want zero-commitment, pay-as-you-go API access
- —Use cases requiring low-cost micropayments per API call ($0.02)
- —Crypto-native workflows already on the Base network with USDC
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/11 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no documentation beyond a landing page listing, no example requests or responses, and the specific endpoint's purpose (/api/v1/keys/11) is ambiguous. The /api, /pricing, and /README pages returned no useful content.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The specific endpoint /api/v1/keys/11 does not match any named API on the landing page — its exact functionality is unknown
- —All documentation pages (/api, /pricing, /README) returned only a 'Connect wallet' prompt with no content
- —No example requests or responses are available to verify endpoint behavior
Citations
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/keys/11 shows maxAmountRequired of 20000 base units of USDC (USD Coin) on Basehttps://lowpaymentfee.com/api/v1/keys/11
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/keys/11