Pay-per-call API suite on Base (USDC) covering data, AI, finance, and utilities at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad collection of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/messages/39` is listed as "Premium API Access." Its x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts HTTP POST and returns `application/json`. Payment is sent to `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout.
The broader platform advertises additional endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, no OpenAPI schema, detailed documentation, or example request/response payloads were found during crawling; the docs, pricing, and README pages all returned only a "Connect wallet" prompt with no further content.
Capabilities
Use cases
- —Calling AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto quotes, gas estimates, and exchange rates on a per-call basis
- —Running geocoding or data validation tasks with instant pay-as-you-go pricing
- —Exporting data or generating analytics reports via lightweight HTTP calls
Fit
Best for
- —Agents and bots that need keyless, pay-per-call API access
- —Developers prototyping with multiple utility endpoints at low cost
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/39 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no documentation beyond a landing page listing, no example requests or responses, and the specific purpose of /api/v1/messages/39 is unclear. Most detail pages return only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The specific purpose and expected input/output of /api/v1/messages/39 is undocumented
- —Docs, pricing, and README pages returned no useful content beyond 'Connect wallet'
- —Broad claims about AI, finance, and utility endpoints cannot be independently verified
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/messages/39
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/messages/39