Pay-per-call API platform on Base via x402 — $0.02/request for data, AI, finance, and utility endpoints.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers 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 and settle in USDC on the Base network.
The specific endpoint at `/api/v1/payments/252` is listed as "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02. Payment is made via the x402 exact scheme — no API keys, subscriptions, or rate limits are required. The endpoint accepts POST requests and returns application/json.
Documentation beyond the landing page is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no additional technical content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available. It is unclear what specific functionality the "Premium API Access" endpoint at path /payments/252 provides, as it does not map to any of the named endpoints on the landing page. Agents should treat this endpoint with caution until more documentation is available.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates
- —Running utility operations like geocoding, validation, and data conversion on a per-call basis
- —Integrating pay-per-request data analytics into agent workflows
Fit
Best for
- —AI agents that need on-demand access to diverse API endpoints without subscription overhead
- —Developers prototyping with low-cost, no-commitment API calls
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where per-request pricing may add up versus flat-rate plans
- —Users who need detailed API documentation, request schemas, or SLA guarantees before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/252 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts payments. However, documentation is nearly nonexistent — all subpages render only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, no examples, and the specific purpose of /api/v1/payments/252 ('Premium API Access') is unclear and doesn't match any named endpoint on the landing page. Pricing is clear ($0.02) but everything else must be inferred.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /docs, /pricing, /api, and /README pages contain no usable content (only 'Connect wallet')
- —The endpoint path /api/v1/payments/252 does not correspond to any of the named endpoints listed on the landing page — its actual functionality is unknown
- —No request body schema or response schema is documented anywhere
- —No examples of successful responses are available
Citations
- —All endpoints are priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/252
- —Payment settles on the Base networkhttps://lowpaymentfee.com