x402-gated account balance endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" resource at the path `/api/v1/accounts/50/balance`. It is part of a broader platform that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services — all gated via the x402 payment protocol on the Base network.
The specific endpoint probed returns an x402 challenge requesting payment in USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` on Base) with a `maxAmountRequired` of 20,000 base units. Since USDC uses 6 decimals, this translates to $0.02 per request, consistent with the site's advertised flat pricing of $0.02/request across all endpoints. Payment is made via the `exact` scheme with a 300-second timeout. No API keys or rate limits are required; access is granted purely through the x402 payment header.
The platform's landing page lists additional endpoint categories including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, documentation pages (`/docs`, `/pricing`, `/api`, `/README`) returned only a "Connect wallet" prompt with no substantive content, so the actual behavior and response schemas of these endpoints remain undocumented.
Capabilities
Use cases
- —Querying account balance data via a single paid API call
- —Agent-driven workflows that need on-demand financial data without pre-registration
- —Demonstrating x402 payment protocol integration on Base
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —AI agents that can settle USDC payments on Base per-call
- —Use cases requiring keyless, registration-free API access
Not for
- —High-volume batch queries where $0.02/request adds up significantly
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/50/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no documentation, no OpenAPI schema, no example responses, and the docs/pricing/README pages are all empty stubs showing only 'Connect wallet'. The actual functionality behind '/api/v1/accounts/50/balance' is unclear beyond its title.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) contain no substantive content — only a 'Connect wallet' prompt
- —No OpenAPI or schema describing request parameters or response format for this endpoint
- —The specific resource '/api/v1/accounts/50/balance' has a hardcoded account ID (50); unclear if this is parameterizable
- —Platform lists many endpoint categories but none have documented schemas or example responses
Citations
- —The endpoint returns an x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/accounts/50/balance
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/accounts/50/balance
- —Platform advertises $0.02/request flat pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com