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/53/balance` is gated behind a per-request USDC micropayment on the Base network. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0.02 USD per request), settled to an on-chain address. The endpoint accepts POST requests and returns JSON.
The broader lowpaymentfee.com platform advertises a suite of pay-per-call APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto 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 commitments required — payment is handled entirely via the x402 protocol on Base.
However, the specific endpoint being listed here (`/api/v1/accounts/53/balance`) is not documented on the site's landing page among the advertised APIs. Its purpose appears to be retrieving the balance for account ID 53, but no further documentation, request/response schemas, or examples are available. The docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional content.
Capabilities
Use cases
- —Querying account balance for account 53 via a single micropayment
- —Demonstrating x402 protocol integration for agent-to-API payments
- —Building pay-as-you-go workflows that settle in USDC on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need to make authenticated-by-payment API calls
- —Use cases requiring no API key or subscription management
Not for
- —Production workloads requiring documented request/response schemas
- —Bulk or batch account balance queries across many accounts
- —Users who need fiat-only payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/53/balance \
-H "X-PAYMENT: <x402_payment_token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but this specific endpoint is not documented among the site's advertised APIs. No request/response schema, no examples, and all doc pages render only 'Connect wallet'. The endpoint's actual functionality is unclear beyond the path-implied 'account balance' purpose.
Warnings
- —This specific endpoint (/api/v1/accounts/53/balance) is not listed among the site's advertised APIs — its purpose and output are unverified.
- —All documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no usable content.
- —No request body schema or response schema is available; example_request_json and example_response_json are null.
- —The endpoint appears to be hardcoded to account ID 53; it is unclear if other account IDs are supported or what 'accounts' refers to in this context.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (USD Coin) on Base networkhttps://lowpaymentfee.com/api/v1/accounts/53/balance
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/accounts/53/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 site advertises APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com