x402-gated premium API endpoint on Base, pay-per-call with USDC at $0.02/request.
What it does
lowpaymentfee.com hosts a collection of x402-protocol pay-per-request API endpoints on the Base network, settled in USDC. The specific endpoint `/api/v1/benefits/12` is listed as "Premium API Access" and returns a 402 challenge requiring an exact-scheme USDC payment on Base. The max amount required is 20,000 base units of USDC (6 decimals), which equals $0.02 per request. No API keys or rate limits are advertised — callers simply attach an X-PAYMENT header with a valid x402 payment proof to access the resource.
The broader platform offers endpoints across several 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. The `/api/v1/benefits/12` endpoint does not have a clear public description of what data or functionality it returns beyond the generic "Premium API Access" label, so its exact output is unknown.
Payment is made to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC at contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` on Base. The endpoint accepts POST requests and returns `application/json`. The x402 challenge specifies a maximum timeout of 300 seconds for payment settlement.
Capabilities
Use cases
- —Accessing premium data or services without traditional API key registration
- —Making one-off API calls settled instantly via USDC on Base
- —Integrating pay-per-request endpoints into autonomous agent workflows
Fit
Best for
- —Developers who want instant API access without signup or API keys
- —Agents and bots that can settle x402 payments programmatically
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible USDC wallet or x402 client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/benefits/12 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no documentation on what this specific endpoint returns, no OpenAPI schema, no example requests or responses, and the crawled docs/pricing/README pages are all blank beyond a 'Connect wallet' prompt. The exact functionality behind 'Premium API Access' at /api/v1/benefits/12 is unknown.
Warnings
- —The exact functionality and response format of /api/v1/benefits/12 is undocumented — 'Premium API Access' is the only description available.
- —Documentation pages (/docs, /pricing, /README, /api) returned no meaningful content beyond 'Connect wallet'.
- —No OpenAPI spec or output schema describing the response body was found.
- —The endpoint path '/api/v1/benefits/12' does not match any of the publicly listed API categories on the homepage, suggesting it may be a test or unlisted resource.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/benefits/12
- —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
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/benefits/12
- —Payment recipient address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/benefits/12