Pay-per-call API suite on Base (USDC) covering AI, analytics, 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/ML inference, finance/Web3 data, and general-purpose 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 upfront commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/messages/50` is listed as "Premium API Access" and accepts POST requests. 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 payment is sent to address 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 data 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 /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no further content.
Capabilities
Use cases
- —Agent-driven AI inference (sentiment, summarization, classification) without API key management
- —On-demand financial data retrieval (token quotes, exchange rates, gas estimates) paid per call
- —Lightweight data analytics and reporting with no subscription overhead
- —Geocoding and utility operations for bots or automation pipelines
- —Embedding generation for RAG or search workflows
Fit
Best for
- —AI agents that need keyless, pay-as-you-go access to diverse API capabilities
- —Developers prototyping with multiple API categories without committing to subscriptions
- —Web3-native applications already holding USDC on Base
Not for
- —High-volume production workloads where per-call pricing becomes expensive compared to bulk plans
- —Users who need detailed SLAs, documentation, or guaranteed uptime commitments
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/50 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{"message": "Hello"}'Example
Request
{
"message": "Hello"
}Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no documentation beyond a landing page listing, no example request/response payloads, and the /api, /pricing, and /README pages are empty. The purpose of the specific /messages/50 endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /api, /pricing, and /README pages returned no useful content (only 'Connect wallet')
- —The specific purpose of /api/v1/messages/50 is undocumented — 'Premium API Access' is vague
- —No example responses are available; request format is inferred
- —No information on uptime, SLAs, or rate limits beyond the claim of 'no rate limits'
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/messages/50
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://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/50