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 (account ID 107) behind an x402 paywall. It accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme. The maximum amount required per call is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals).
The broader lowpaymentfee.com platform advertises a suite of pay-per-request APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 data (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/107/balance` — is not among the publicly advertised APIs on the landing page, and its exact response schema is undocumented.
The endpoint is confirmed live: the probe received a proper HTTP 402 x402 challenge with version 1, indicating the paywall is active and ready to accept payments. Documentation pages (/docs, /pricing, /api, /README) all returned only a "Connect wallet" prompt with no substantive content, so details about request parameters and response format remain unknown.
Capabilities
Use cases
- —Querying account balance information for account 107 via a single paid API call
- —Demonstrating x402 payment protocol integration on Base with USDC
- —Building agent workflows that pay per request without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing pay-per-call access without pre-registration
- —Use cases requiring low-cost ($0.02) per-request billing on Base
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need bulk or subscription-based pricing
- —Anyone needing account balance lookups for arbitrary account IDs (this endpoint is hardcoded to account 107)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/107/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation for request parameters, response schema, or what 'account 107 balance' actually returns. The /docs, /pricing, and /README pages are all empty. This specific endpoint is not listed among the platform's advertised APIs, making it effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all return only a wallet-connect prompt with no content
- —This specific endpoint (/api/v1/accounts/107/balance) is not listed among the platform's publicly advertised APIs
- —Request body schema and response schema are completely unknown
- —The endpoint is hardcoded to account ID 107; unclear if other account IDs are supported
Citations
- —The x402 challenge requires 20,000 base units of USDC on Base network (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/accounts/107/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 advertises APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com