Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/297` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 per call. However, documentation is extremely sparse: the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available for any endpoint, including this one.
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 Base who want low-friction API consumption
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —Teams requiring fiat-only payment methods with no crypto wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/297 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts payments. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of this specific endpoint ('/api/v1/transactions/297') is unclear — 'Premium API Access' is generic and undescriptive. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —Docs, API, pricing, and README pages all render only 'Connect wallet' with no content
- —The specific purpose of /api/v1/transactions/297 ('Premium API Access') is undefined — no input/output schema provided
- —Cannot verify what data or functionality this endpoint actually returns
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/297
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com