Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that exposes a broad catalog 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/156` is listed as "Premium API Access." Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335… on Base), which equals $0.02 given USDC's 6 decimals. 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 requests and returns application/json.
Note that the crawled documentation is extremely thin — the `/api`, `/pricing`, and `/README` pages all returned only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available. The purpose of the `/api/v1/messages/156` path specifically is unclear from the available material; it does not appear in the homepage catalog, which lists different endpoint paths. The endpoint is live (returns a valid 402 challenge), but what it actually returns upon successful payment is unknown.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data like token quotes, exchange rates, and gas estimates on a per-call basis
- —Running data analytics queries and exporting insights with micropayments
- —Using utility services like geocoding, validation, and format conversion via pay-per-request
Fit
Best for
- —Agents or bots that need instant, keyless API access with crypto micropayments
- —Developers prototyping with low-cost, no-commitment API calls
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads needing guaranteed SLAs and detailed documentation
- —Users who cannot transact in USDC on the Base network
- —Applications requiring well-documented request/response schemas before integration
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/156 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no OpenAPI spec, no request/response schema, no examples, and no documentation beyond a homepage listing. The specific /api/v1/messages/156 path is not even listed on the homepage catalog, making its purpose unclear. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /api/v1/messages/156 path does not appear in the homepage's published API catalog — its specific function is unknown
- —All documentation pages (/api, /pricing, /README) returned only 'Connect wallet' with no useful content
- —No request body schema or response schema is documented anywhere
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/156 advertises maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/messages/156
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com