Pay-per-call API platform on Base (USDC) via x402 — $0.02/request, no API keys required.
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/163` is labeled "Premium API Access" and charges up to $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, accounts, or rate limits are advertised — callers simply attach an x402 payment header to each request.
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 the same $0.02/request price point. Payments settle to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base.
Note that the specific functionality behind the `/api/v1/payments/163` endpoint is unclear — the description is generic ("Premium API Access") and no request/response schema is documented beyond the x402 challenge. The docs, pricing, and README pages all returned only a "Connect wallet" prompt with no additional technical documentation. Treat this listing with caution: the platform appears live but documentation is extremely thin.
Capabilities
Use cases
- —Accessing premium API endpoints without creating an account or managing API keys
- —Making one-off paid API calls settled instantly via USDC on Base
- —Agent-driven workflows that need frictionless per-request billing
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents with x402-compatible wallets on Base
- —Prototyping workflows that need instant, keyless API access
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume production use cases where $0.02/request adds up and bulk pricing is needed
- —Users without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/163 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and accepts USDC on Base at $0.02/request. However, there is no OpenAPI schema, no request/response examples, and all documentation pages return only a wallet-connect prompt. The specific purpose of the /payments/163 endpoint is undocumented beyond the generic label "Premium API Access."
Warnings
- —No API documentation available — docs, pricing, and README pages all return only 'Connect wallet' with no technical content.
- —The specific functionality of /api/v1/payments/163 ('Premium API Access') is not described anywhere; it is unclear what data or service it returns.
- —No request body schema or response schema is documented.
- —The platform lists many endpoint categories (AI, finance, analytics, etc.) but none have visible documentation to verify actual functionality.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 USDC base units (=$0.02) on Base networkhttps://lowpaymentfee.com/api/v1/payments/163
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/163
- —Multiple API categories listed: Data & Analytics, AI & ML, Finance & Web3, Infrastructurehttps://lowpaymentfee.com