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 provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/keys/95` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 protocol — no API keys, accounts, or subscriptions are required; callers simply attach an X-PAYMENT header with a valid payment proof.
The wider 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.
However, the specific endpoint probed (`/api/v1/keys/95`) does not clearly map to any of the documented API categories. Its description is simply "Premium API Access," and no schema, request/response examples, or detailed documentation are available for it. The crawled docs pages (/api, /pricing, /README) all returned only a "Connect wallet" prompt with no substantive content. Without further documentation, the exact functionality of this particular endpoint remains unclear.
Capabilities
Use cases
- —Agents needing on-demand API access without signup or API key management
- —Paying per-call for AI inference (sentiment, summarization, classification, embeddings)
- —Fetching real-time financial data or crypto gas estimates with micropayments
- —Running utility operations like geocoding or data validation without a subscription
Fit
Best for
- —AI agents that need frictionless, keyless API access via x402
- —Developers wanting pay-as-you-go pricing with no minimums or commitments
- —Crypto-native applications already operating on the Base network
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or rate-limited plans
- —Anyone without USDC on Base for payment
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/95 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no documentation beyond a landing page listing. The specific endpoint '/api/v1/keys/95' has no documented purpose beyond 'Premium API Access'. Docs pages returned only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The endpoint path '/api/v1/keys/95' does not match any of the documented API categories on the landing page
- —All documentation pages (/api, /pricing, /README) returned only 'Connect wallet' with no substantive content
- —Exact functionality and expected request/response format are unknown
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/keys/95
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/keys/95
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com