Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are settled on the Base network using USDC, with a uniform price of $0.02 per request. The x402 protocol eliminates the need for API keys, accounts, or rate limits — callers simply attach an X-PAYMENT header with a signed USDC payment to access any endpoint instantly.
The specific endpoint at `/api/v1/payments/291` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USDC, i.e., $0.02) on the Base network. The payment is made to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the USDC contract at `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`. The endpoint accepts POST requests and returns `application/json`.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation beyond the landing page is extremely sparse (docs, pricing, and API pages all render only a "Connect wallet" prompt), so the actual functionality, input schemas, and response formats for individual endpoints are not documented in any accessible way.
Capabilities
Use cases
- —Accessing premium API endpoints without creating accounts or managing API keys
- —Making one-off API calls with instant USDC micropayments on Base
- —Agent-driven workflows that need frictionless pay-per-use API access
Fit
Best for
- —Developers who want zero-signup API access via crypto micropayments
- —AI agents that need to programmatically purchase API calls on-chain
- —Users already operating on the Base L2 network with USDC
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —Developers who prefer traditional API key or OAuth authentication
- —Anyone without a Base-compatible wallet and USDC balance
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/291 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation is essentially nonexistent — docs, pricing, and API pages all show only 'Connect wallet' with no schema, examples, or descriptions of what the endpoint actually returns. The 'Premium API Access' label is generic and uninformative. Without input/output schemas or any documentation, this is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, API, and README pages all render only 'Connect wallet'
- —No input or output schema provided for this endpoint
- —The label 'Premium API Access' is generic; the actual functionality of /api/v1/payments/291 is unknown
- —This specific endpoint path (/api/v1/payments/291) does not appear in the site's listed API catalog, making its purpose unclear
Citations
- —Uniform pricing of $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0.02 USD) on Base networkhttps://lowpaymentfee.com/api/v1/payments/291
- —USDC asset contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/291
- —Platform offers endpoints across data analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com