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/49` is listed as "Premium API Access" and costs $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, accounts, or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 priced at $0.02 per request and settle in USDC on Base.
However, the specific functionality behind the `/api/v1/transactions/49` endpoint is unclear. The description is simply "Premium API Access" with no further documentation, input schema, or example responses available. The docs, pricing, and README pages on the site all render only a "Connect wallet" prompt with no additional content. Without documentation or example payloads, it is difficult to determine what data or service this particular endpoint returns.
Capabilities
Use cases
- —Accessing premium API data without creating an account or managing API keys
- —Making one-off API calls with instant USDC micropayments on Base
- —Agent-driven workflows that need frictionless pay-per-use endpoints
Fit
Best for
- —Developers who want zero-signup API access via crypto micropayments
- —AI agents that can autonomously pay for API calls using x402
- —Users already holding USDC on the Base network
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Developers who prefer traditional API key authentication and fiat billing
- —High-volume consumers who need bulk pricing or subscription discounts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/49 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no input/output schema, no example requests or responses, and the purpose of this specific endpoint (/api/v1/transactions/49) is entirely opaque. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — docs, pricing, and README pages all show only 'Connect wallet' with no content
- —The specific purpose of /api/v1/transactions/49 ('Premium API Access') is undocumented and unclear
- —No input or output schema provided; callers cannot determine what to send or what to expect back
- —No OpenAPI spec, ai-plugin manifest, or agents.txt discovered
Citations
- —Endpoint returns 402 with x402 challenge advertising USDC on Base network at 20000 base unitshttps://lowpaymentfee.com/api/v1/transactions/49
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/49
- —Multiple API categories listed: Data & Analytics, AI & ML, Finance & Web3, Infrastructurehttps://lowpaymentfee.com