Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/trades/27` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform offers 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. However, the specific `/api/v1/trades/27` endpoint does not clearly map to any of these advertised categories, and no documentation describes what data or functionality it returns.
The endpoint is live and responds with a well-formed x402 challenge. Payment settles to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base. The method is POST and the response MIME type is `application/json`. Documentation pages beyond the landing page are effectively empty (showing only "Connect wallet"), so the actual response schema and input parameters for this endpoint are unknown.
Capabilities
Use cases
- —Accessing trade-related data or functionality via a single paid API call
- —Integrating pay-per-use API access into agent workflows without API keys
- —Demonstrating x402 payment protocol integration on Base
Fit
Best for
- —Developers experimenting with x402 micropayment protocol
- —Agents needing keyless, pay-per-call API access on Base
- —Projects that want to avoid subscription commitments for occasional API calls
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/trades/27 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation on what /api/v1/trades/27 actually returns, no input/output schema, and no example responses. The docs, pricing, and README pages are all blank beyond a wallet-connect prompt. The endpoint's purpose is unclear.
Warnings
- —No documentation available for the /api/v1/trades/27 endpoint — its purpose and response format are unknown
- —The endpoint path '/api/v1/trades/27' does not appear in the site's advertised API catalog
- —All documentation pages (docs, pricing, README) render only a 'Connect wallet' prompt with no useful content
- —No input parameters or output schema are documented anywhere
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/trades/27
- —USDC contract address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/trades/27
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com