Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API marketplace that exposes a broad set of 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 utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request, settled in USDC on the Base network via the x402 protocol.
The specific endpoint `/api/v1/messages/172` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals = $0.02). Payment is made via the x402 exact scheme with no API keys, no rate limits, and no upfront commitments required. The endpoint accepts HTTP POST and returns application/json.
Documentation beyond the landing page is sparse — the /api, /pricing, and /README pages all resolve to a wallet-connect prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material. The purpose of the `/api/v1/messages/172` endpoint specifically is unclear; it may be a generic message retrieval or content endpoint, but this cannot be confirmed from available sources.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data and crypto gas estimates on a per-call basis
- —Running geocoding or data validation tasks with instant pay-as-you-go pricing
- —Exporting analytics data or generating reports without subscription commitments
Fit
Best for
- —Agents or developers who want zero-signup, pay-per-use API access
- —Projects needing lightweight AI inference at very low per-call cost
- —Crypto-native applications already operating on Base with USDC
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads that would benefit from bulk pricing or rate guarantees
- —Developers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/172 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/messages/172",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-token>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and the specific purpose of /api/v1/messages/172 is unclear. The /api, /pricing, and /README pages are all gated behind a wallet-connect wall with no content.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The specific purpose of /api/v1/messages/172 ('Premium API Access') is not documented
- —All documentation pages (/api, /pricing, /README) resolve to a wallet-connect prompt with no content
- —No example request or response payloads are available
- —Cannot verify that the advertised AI, finance, and utility endpoints are actually functional
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/messages/172 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/messages/172
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com