Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. Each call costs $0.02 in USDC (USD Coin) with no API keys, no rate limits, and no subscriptions required. The specific endpoint at `/api/v1/messages/149` is labeled "Premium API Access" and accepts POST requests, settling payments on-chain to a designated wallet address.
The broader platform advertises 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 listed at the same $0.02 per request price point.
The x402 challenge for this endpoint confirms it is live, requesting a maximum of 20,000 base units of USDC (6 decimals = $0.02) on the Base network. The payment scheme is "exact" with a 300-second timeout. No OpenAPI schema, detailed documentation, or example request/response payloads were found during the crawl — the `/api`, `/pricing`, and `/README` pages all returned only a "Connect wallet" prompt with no additional content.
Capabilities
Use cases
- —Accessing premium content or data behind a per-request paywall without needing an API key or subscription
- —Agent-driven workflows that need to pay for API calls programmatically using on-chain USDC
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —AI agents that can settle USDC payments on Base for per-call access
- —Users who want pay-as-you-go API access without account creation
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who prefer subscription-based pricing over per-request payments
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/149 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and network details. However, there is no OpenAPI schema, no documentation beyond a landing page listing, no example requests or responses, and the specific purpose of `/api/v1/messages/149` is unclear. The crawled docs pages were empty (wallet-connect only). This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The specific function of /api/v1/messages/149 is undocumented — 'Premium API Access' is the only description
- —All documentation pages (/api, /pricing, /README) returned no useful content beyond 'Connect wallet'
- —Request and response formats are unknown; no examples could be sourced
Citations
- —The endpoint returns a valid x402 402 challenge requesting 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/messages/149
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/messages/149