Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are pay-per-request using USDC on the Base network, settled via the x402 protocol. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/160` is listed as "Premium API Access" and requires a maximum of 20,000 base units of USDC (0.02 USDC, i.e., $0.02) per call. The platform advertises additional 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 (geocoding, validation, conversion, generation). All are priced at $0.02 per request.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The x402 challenge is live and well-formed, confirming the endpoint accepts POST requests and settles in USDC on Base, but without documentation it is unclear what input this specific endpoint expects or what it returns.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) on a per-call payment basis without API keys
- —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates
- —Running data analytics queries (metrics, reports, insights) with per-request billing
- —Using utility services like geocoding, validation, and data conversion via micropayments
Fit
Best for
- —Developers who want instant API access without signup or API key management
- —Agents and bots that can settle payments programmatically via x402 on Base
- —Low-volume or sporadic usage where $0.02/request is more economical than a subscription
Not for
- —High-volume production workloads where per-request pricing would be expensive at scale
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/160 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint works and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty beyond a wallet-connect prompt. The purpose of this specific endpoint (/api/v1/transactions/160) is unclear beyond the generic label 'Premium API Access'.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only 'Connect wallet' with no usable content
- —No OpenAPI or JSON schema available for any endpoint
- —The specific purpose and expected input/output of /api/v1/transactions/160 is undocumented
- —The broad catalog of endpoints listed on the homepage cannot be verified for actual functionality
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/transactions/160 requires maxAmountRequired of 20000 base units of USDC (USD Coin) on Basehttps://lowpaymentfee.com/api/v1/transactions/160
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/160