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/charges/252` is labeled "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 crawled documentation pages (docs, pricing, README) returned only a wallet-connect prompt with no substantive content, so the actual behavior, request/response schemas, and data sources behind these endpoints remain undocumented.
The `/api/v1/charges/252` endpoint is live and returns a valid x402 challenge (HTTP 402) with scheme "exact" on the Base network, paying to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` in USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The endpoint accepts POST requests. Without documentation or example responses, it is unclear what data this specific charge endpoint returns versus the other named endpoints on the platform.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification) without managing API keys
- —Fetching real-time crypto gas estimates or token price quotes with per-call USDC micropayments
- —Geocoding or data validation as a utility service paid per request on Base
Fit
Best for
- —Developers and agents wanting zero-commitment, pay-as-you-go API access
- —x402-compatible agents that can settle USDC on Base
- —Use cases requiring small, infrequent API calls where subscription pricing is wasteful
Not for
- —High-volume production workloads where per-call pricing at $0.02 adds up quickly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
- —Callers without USDC on Base or x402 payment capability
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/252 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no request/response schema, and no examples. The docs, pricing, and README pages all returned only a wallet-connect prompt. The purpose of the specific /charges/252 endpoint versus the named API routes is unclear.
Warnings
- —No API documentation available — docs, pricing, and README pages are empty beyond a wallet-connect prompt
- —No request or response schema provided for any endpoint
- —The specific endpoint /api/v1/charges/252 does not match any of the named API routes listed on the homepage; its actual functionality is unknown
- —Cannot verify what data or service is actually returned after payment
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/252
- —All listed endpoints are priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —The platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/charges/252