x402-gated account balance endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides an account balance lookup via the x402 payment protocol. The specific resource `/api/v1/accounts/199/balance` is gated behind an x402 challenge requiring payment in USDC on the Base network. The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 per request. Payment is made via the "exact" scheme to a specified wallet address, with a timeout of 300 seconds.
The broader lowpaymentfee.com platform advertises a suite of x402-gated APIs spanning 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 listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments.
However, the specific endpoint being listed here — `/api/v1/accounts/199/balance` — is not among the publicly documented APIs on the landing page. Its purpose appears to be retrieving the balance of account ID 199, but no schema, example request, or example response is available. Documentation pages (/docs, /api, /pricing, /README) returned only a "Connect wallet" prompt with no substantive content. The endpoint is confirmed live via a valid 402 challenge.
Capabilities
Use cases
- —Querying account balance for a specific account ID via micropayment
- —Integrating pay-per-call balance lookups into agent workflows
- —Demonstrating x402 payment protocol usage on Base
Fit
Best for
- —Agents needing on-demand account balance data without API key management
- —Developers experimenting with x402 payment-gated endpoints
- —Low-volume, pay-as-you-go balance queries
Not for
- —High-volume balance monitoring requiring bulk or subscription pricing
- —Users who need detailed documentation or response schema guarantees
- —Production systems requiring SLA or uptime commitments
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/199/balance \
-H "X-PAYMENT: <x402_payment_token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (valid 402 challenge captured) and pricing is clear ($0.02/request in USDC on Base). However, this specific endpoint is not documented on the site, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty stubs showing only 'Connect wallet'. The endpoint's actual functionality is inferred solely from its URL path.
Warnings
- —This specific endpoint (/api/v1/accounts/199/balance) is not listed among the provider's publicly documented APIs
- —All documentation pages (/docs, /api, /pricing, /README) returned no substantive content
- —No request or response schema is available; actual output format is unknown
- —The platform appears to be a demonstration or early-stage project with minimal documentation
Citations
- —The x402 challenge requires maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/accounts/199/balance
- —All listed APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com