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, 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 at `/api/v1/messages/28` is labeled "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. Payment is made via the x402 exact scheme with no API keys or rate limits required. The endpoint accepts HTTP POST requests and returns `application/json` responses. The payment address is `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` and the timeout is 300 seconds.
Documentation beyond the landing page is sparse — the /api, /pricing, and /README routes all resolve to a wallet-connect prompt with no additional content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the `/messages/28` endpoint actually returns. The site advertises many endpoints but the specific functionality of this particular route (messages/28) is unclear from available materials.
Capabilities
Use cases
- —Accessing premium API data without subscription or API key management
- —Agent-driven pay-per-call workflows settled in USDC on Base
- —Programmatic access to data, AI, finance, or utility endpoints with micropayments
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost per-request pricing without rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/28 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI spec, no request/response schema, no documentation for the /messages/28 endpoint specifically, and the crawled pages beyond the landing page are empty wallet-connect prompts. The actual functionality of this specific endpoint is unknown.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The specific purpose of /api/v1/messages/28 ('Premium API Access') is not documented — unclear what it returns
- —All secondary pages (/api, /pricing, /README) resolve to a wallet-connect prompt with no useful content
- —No request body schema or response examples are available
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/28 requires up to 20,000 base units of USDC (USD Coin) on Base with a 300-second timeouthttps://lowpaymentfee.com/api/v1/messages/28
- —The site offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com