Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request 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, payable in USDC on the Base network.
The specific endpoint at `/api/v1/transactions/118` is labeled "Premium API Access" and returns a live x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $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 requests and returns application/json.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the `/api/v1/transactions/118` endpoint actually returns. The platform's landing page lists many endpoints but provides no detail on request parameters or response formats for any of them.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API keys
- —Fetching real-time crypto prices, exchange rates, and gas estimates on a per-call basis
- —Running geocoding, validation, or data conversion tasks with micropayments
- —Exporting data or generating analytics reports with no subscription commitment
Fit
Best for
- —Agents or developers who want key-free, pay-as-you-go API access
- —Low-volume or sporadic API consumers who don't want subscriptions
- —x402-compatible agents settling payments in USDC on Base
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or rate-limited tiers
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/118 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no examples. The specific purpose of /api/v1/transactions/118 ('Premium API Access') is unclear beyond its label.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) contain no usable content — only a 'Connect wallet' prompt.
- —No OpenAPI or schema documentation available for any endpoint.
- —The purpose and expected input/output of /api/v1/transactions/118 is undocumented; 'Premium API Access' is vague.
- —The platform lists many endpoints on its landing page but provides no detail on request parameters or response formats for any of them.
Citations
- —The endpoint returns a live x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/118
- —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
- —Documentation pages render only a 'Connect wallet' prompt with no further contenthttps://lowpaymentfee.com/docs