Pay-per-request API platform on Base network via x402 — $0.02/call, 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 infrastructure utilities. Every endpoint is priced at $0.02 per request, payable in USDC on the Base network with no API keys, rate limits, or upfront commitments. The x402 protocol handles payment inline: callers attach a payment header to each HTTP request and receive the response immediately upon settlement.
The specific endpoint at `/api/v1/transfers/15` is listed as "Premium API Access" with a maximum charge of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this equals $0.02 per call, consistent with the site's uniform pricing. 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 generation. However, documentation beyond the landing page is essentially empty (all sub-pages only show "Connect wallet"), so the actual behavior, request schemas, and response formats for each endpoint — including this one — are undocumented. The endpoint is live and returning a valid x402 402 challenge.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, on-demand API access
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —AI agents that can settle USDC payments on Base per call
- —Users who want no-signup, no-API-key access to utility endpoints
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume consumers who prefer subscription or bulk pricing over per-call payments
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/15 \
-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 documentation, no OpenAPI schema, no request/response examples, and the purpose of '/api/v1/transfers/15' specifically is entirely opaque. All doc pages return only 'Connect wallet' with no content.
Warnings
- —No documentation available — all doc/pricing/API pages are empty beyond 'Connect wallet'
- —The specific purpose and expected input/output of /api/v1/transfers/15 is unknown; 'Premium API Access' is a generic label
- —No OpenAPI spec or request/response schema provided
- —Cannot verify what data or service this endpoint actually returns
Citations
- —Uniform pricing of $0.02 per request across all endpoints, no API keys, no rate limitshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (6 decimals = $0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transfers/15
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transfers/15
- —Platform lists endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com