Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
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, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 protocol handles payment inline: callers attach an X-PAYMENT header with a signed USDC payment to each request.
The specific endpoint at `/api/v1/charges/314` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. 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 request/response schemas for individual endpoints are unknown.
Capabilities
Use cases
- —Agents that need on-demand API access without pre-registration or API keys
- —Programmatic access to analytics, AI inference, or financial data with per-call USDC payments
- —Testing x402 payment flows on Base network
Fit
Best for
- —Developers or agents wanting zero-signup, pay-as-you-go API access
- —x402-compatible wallets and agent frameworks on Base
- —Low-volume or sporadic API consumers who prefer per-call pricing
Not for
- —High-volume consumers needing bulk pricing or subscription discounts
- —Users without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/314 \
-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, confirming pricing and payment details. However, documentation is essentially absent — the docs, pricing, and API pages all show only 'Connect wallet' with no schema, example payloads, or response formats. The specific purpose of '/api/v1/charges/314' beyond 'Premium API Access' is unclear, and no input/output schemas are available.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) are all empty beyond a 'Connect wallet' prompt — no usable API documentation exists.
- —The specific functionality of /api/v1/charges/314 ('Premium API Access') is not described anywhere; it may be a generic or placeholder endpoint.
- —No OpenAPI spec, no request/response schemas, and no example payloads are available.
- —The platform lists many endpoints on its landing page but none have documented schemas or behavior.
Citations
- —All endpoints priced at $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 (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/charges/314
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com