Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request using USDC on the Base network via the x402 protocol, meaning no API keys, accounts, or subscriptions are needed — callers simply attach a payment header to each request.
The specific endpoint at `/api/v1/payments/285` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per request, consistent with the site's uniform $0.02/request pricing. Payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. Documentation pages exist but appear to require wallet connection to view, so detailed request/response schemas are not publicly available.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification) without managing API keys
- —Fetching real-time crypto token quotes and gas estimates with per-call payment
- —Geocoding or data validation as a utility service paid in USDC on Base
- —Exporting analytics data or generating reports with no subscription commitment
Fit
Best for
- —AI agents and bots that can attach x402 payment headers automatically
- —Developers who want zero-signup, pay-as-you-go API access
- —Web3-native applications already operating on the Base network
Not for
- —Users who need high-volume bulk pricing or subscription discounts
- —Applications requiring detailed API documentation and typed schemas before integration
- —Callers who cannot transact in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/285 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no request/response examples, and documentation pages are gated behind wallet connection. The specific purpose of the '/api/v1/payments/285' endpoint beyond 'Premium API Access' is unclear, making this effectively a stub listing.
Warnings
- —No public API documentation — all doc pages require wallet connection and render only 'Connect wallet'
- —No OpenAPI or JSON schema available for request/response formats
- —The specific functionality of /api/v1/payments/285 ('Premium API Access') is not described anywhere — it may be a generic or placeholder endpoint
- —The broader platform lists many endpoints but none have documented input/output schemas
Citations
- —Uniform pricing of $0.02 per request across all endpoints, no API keys, no rate limitshttps://lowpaymentfee.com
- —Platform offers endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base (=$0.02)https://lowpaymentfee.com/api/v1/payments/285
- —Payment asset is USDC at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/285