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 `/api/v1/keys/70` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
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 listed endpoints share the same $0.02/request pricing. However, the specific endpoint being listed here (`/api/v1/keys/70`) does not clearly map to any of the named endpoints on the landing page, and its actual functionality is unclear — it may be a generic key-generation or key-access endpoint.
The x402 challenge was successfully captured, confirming the endpoint is live. It accepts POST requests, returns application/json, and settles payments to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base. No OpenAPI schema, detailed documentation, or example responses were found during the crawl.
Capabilities
Use cases
- —Programmatic access to a pay-per-call API without needing API keys or subscriptions
- —Agent-driven workflows that need on-demand API calls settled via crypto micropayments
- —Accessing data, AI inference, finance, or utility endpoints with per-request USDC payments
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments on Base
- —Users who prefer crypto micropayments over traditional API key subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/70 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no documentation, no example requests or responses, and the specific endpoint /api/v1/keys/70 is not described anywhere on the site. The actual functionality of this endpoint is unknown.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The endpoint path /api/v1/keys/70 does not match any of the named endpoints on the landing page — its actual functionality is unclear
- —Crawled /api, /pricing, and /README pages returned only 'Connect wallet' with no useful content
- —No example request or response bodies are available
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/keys/70
- —All listed endpoints are priced at $0.02/request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/keys/70
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com