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 platform that offers 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 at `/api/v1/transactions/77` is listed as "Premium API Access" and returns a valid 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with a 300-second timeout. No API keys or rate limits are advertised — access is purely pay-per-call.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all resolve to a minimal "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The landing page lists endpoint paths and prices but does not describe input parameters or response formats for any endpoint, including the probed `/api/v1/transactions/77` path. The purpose of the "transactions/77" endpoint specifically is unclear — it may be a demo or placeholder resource.
Capabilities
Use cases
- —Accessing real-time financial data (prices, exchange rates, gas estimates) with per-call USDC payments
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) without API key signup
- —Geocoding and data validation via utility endpoints with instant crypto-settled access
- —Exporting data or generating analytics reports on demand
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access settled in USDC on Base
- —Agents or bots that need programmatic access to diverse utility endpoints via x402
- —Users who prefer crypto micropayments over traditional API key subscriptions
Not for
- —Production workloads requiring documented request/response schemas and SLAs
- —Users without USDC on Base network or unfamiliar with x402 payment protocol
- —High-volume use cases where per-call pricing at $0.02 would be cost-prohibitive compared to subscription plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/77 \
-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 network. However, documentation is essentially nonexistent — all doc/pricing/readme pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, no examples, and the specific purpose of '/api/v1/transactions/77' is unclear. The listing is effectively a stub with confirmed liveness.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) are all empty beyond a 'Connect wallet' prompt
- —No OpenAPI or schema documentation available for any endpoint
- —The specific endpoint /api/v1/transactions/77 is not listed on the landing page among the advertised APIs — its purpose is unclear
- —No request parameters or response format documented anywhere in the crawl
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/77
- —Categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com