Pay-per-call API platform on Base network via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, paid in USDC on the Base network. The platform uses the x402 payment protocol, meaning callers attach a payment header to each request rather than managing API keys or subscriptions.
The specific endpoint at `/api/v1/customers/71` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. The payment is settled to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the "exact" scheme. 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 essentially empty (all sub-pages just show "Connect wallet"), so the actual behavior, request schemas, and response formats for any of these endpoints are undocumented. Without request/response examples or OpenAPI specs, integrators will need to experiment to discover the expected input and output formats.
Capabilities
Use cases
- —Accessing premium data or analytics endpoints without managing API keys or subscriptions
- —Making one-off API calls with instant USDC micropayments on Base
- —Integrating pay-per-use API access into autonomous agent workflows
Fit
Best for
- —Developers who want keyless, pay-per-call API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-friction API access at $0.02 per request
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who want bulk pricing or subscription discounts
- —Developers without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/customers/71 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI spec, no documentation of request/response schemas, and all doc pages are empty stubs. The purpose of the /api/v1/customers/71 endpoint specifically is unclear beyond the generic label 'Premium API Access'. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all doc/pricing/README pages return only 'Connect wallet'
- —The specific purpose and expected input/output of /api/v1/customers/71 is undocumented
- —No request or response examples are available anywhere in the crawled material
- —The broader platform lists many endpoints but none have documented schemas
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limitshttps://lowpaymentfee.com
- —Payment is in USDC on Base network (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/customers/71
- —maxAmountRequired is 20000 base units of USDC (6 decimals = $0.02)https://lowpaymentfee.com/api/v1/customers/71
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com