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 at `/api/v1/payments/108` is labeled "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requiring up to 20,000 base units of USDC (0.02 USD) per call, settled to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base.
The broader platform advertises multiple API categories including 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 listed at $0.02 per request. The platform emphasizes no API keys, no rate limits, no minimums, and instant access.
However, the specific functionality behind the `/api/v1/payments/108` endpoint is unclear — it does not map to any of the named API categories on the landing page. Documentation pages (`/docs`, `/pricing`, `/api`, `/README`) all returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation available for any endpoint. The actual data sources, model providers, and response formats are unknown.
Capabilities
Use cases
- —Paying per-call for API access without subscriptions or API keys
- —Integrating x402-compatible agents with a low-cost endpoint
- —Testing x402 protocol payment flows on Base network
Fit
Best for
- —Developers experimenting with x402 pay-per-request patterns
- —Agents that need keyless, on-demand API access via crypto micropayments
- —Projects already operating on the Base L2 network with USDC
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Production workloads requiring well-documented request/response schemas
- —Users without USDC on the Base network
Quick start
# The endpoint requires an x402 payment header (USDC on Base).
# 1. Send a POST to get the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/payments/108
# 2. Parse the 402 response, construct an X-PAYMENT header
# with a signed USDC transfer of 0.02 USD on Base, then retry.Endpoint
Quality
The x402 challenge is live and confirms pricing, but the specific endpoint's purpose is undocumented. All doc pages return only 'Connect wallet' with no content. No OpenAPI schema, no request/response examples, and no description of what '/api/v1/payments/108' actually returns. This is effectively a stub listing.
Warnings
- —The endpoint path /api/v1/payments/108 does not correspond to any named API on the landing page — its actual functionality is unknown.
- —All documentation pages (/docs, /pricing, /api, /README) returned only 'Connect wallet' with no substantive content.
- —No OpenAPI schema, request format, or response examples are available for any endpoint.
- —The platform lists many API categories (AI, finance, data, etc.) but provides zero evidence of actual underlying data sources or models.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/108
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, no minimums, instant access, Base networkhttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) returned only 'Connect wallet'https://lowpaymentfee.com/docs