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/transactions/260` is listed as "Premium API Access" and returns a 402 challenge requesting 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 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.
This particular endpoint (`/api/v1/transactions/260`) is labeled "Premium API Access" but its actual functionality is not documented beyond that label. The crawled docs, pricing, API, and README pages all returned only a "Connect wallet" prompt with no additional documentation. Without further detail on what data or service this endpoint returns, callers should treat it as an opaque paid endpoint whose response schema is unknown.
Capabilities
Use cases
- —Programmatic access to paid API endpoints without traditional API key management
- —Agent-driven workflows that need to pay per call using on-chain USDC
- —Exploring x402 protocol integration for micropayment-gated services
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —AI agents that can autonomously pay for API calls with USDC
- —Use cases requiring keyless, pay-as-you-go API access
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume callers who prefer subscription-based pricing over per-request fees
- —Anyone needing fiat-only payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/260 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no documentation for what this specific endpoint actually does, no request/response schema, and all doc pages return only 'Connect wallet'. The listing is effectively a stub with pricing info but no functional specification.
Warnings
- —No documentation available — all doc/pricing/API/README pages return only 'Connect wallet'
- —The actual functionality of /api/v1/transactions/260 ('Premium API Access') is completely undocumented
- —No request body schema or response schema provided
- —No OpenAPI spec or AI plugin manifest found
- —Cannot verify what data or service this endpoint returns
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/260
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/260
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com