Pay-per-call API platform on Base 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 infrastructure utilities. Every endpoint is priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol. There are no API keys, no rate limits, and no signup — callers simply attach an X-PAYMENT header with a valid x402 payment proof to access any endpoint.
The specific endpoint at `/api/v1/payments/177` 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 categories including: metrics and reports APIs, data export and insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation utilities. However, documentation pages (docs, pricing, README) all returned only a "Connect wallet" prompt with no substantive content, so the actual behavior and response schemas of these endpoints are undocumented in the crawled material.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto prices, gas estimates, and exchange rates on a per-call basis
- —Running geocoding or data validation as a utility service with instant pay-per-use billing
- —Exporting data or generating analytics reports without subscription commitments
Fit
Best for
- —Agents and bots that need keyless, on-demand API access paid in USDC
- —Developers prototyping with low-cost, no-commitment API calls
- —Web3-native applications that already hold USDC on Base
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
- —Teams without crypto wallets or USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/177 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/payments/177",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-proof>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no documentation (all doc pages return only 'Connect wallet'), no example responses, and the actual functionality behind 'Premium API Access' at /api/v1/payments/177 is completely undescribed. The platform lists many endpoint categories but provides no detail on inputs, outputs, or behavior.
Warnings
- —All documentation pages (/docs, /pricing, /README, /api) returned only 'Connect wallet' with no substantive content
- —No OpenAPI or schema available — request/response formats are unknown
- —The specific endpoint /api/v1/payments/177 is labeled 'Premium API Access' but its actual functionality is undocumented
- —The broad catalog of advertised endpoints (AI, finance, utils) cannot be verified from crawled content
Citations
- —Endpoint returns 402 with x402 challenge requesting 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/177
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/177
- —Platform advertises $0.02/request pricing with no API keys, no rate limitshttps://lowpaymentfee.com
- —Categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com