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/189/balance` is gated behind a per-request USDC payment 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 a specified wallet address. The endpoint accepts POST requests and returns JSON.
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 instant access via the Base network.
However, the specific endpoint being listed here — `/api/v1/accounts/189/balance` — is not among the publicly documented APIs on the landing page. Its purpose ("Premium API Access") and response format are not documented beyond the x402 challenge metadata. There is no OpenAPI spec, no usage examples, and the docs/pricing/README pages returned only a wallet-connect prompt with no substantive content. Treat this as a minimally documented endpoint with verified liveness.
Capabilities
Use cases
- —Querying account balance information via a pay-per-request model
- —Agent-initiated balance lookups without API key provisioning
- —Programmatic access to account data settled in USDC on Base
Fit
Best for
- —Agents needing keyless, pay-per-call account balance queries
- —Developers testing x402 payment flows on Base
- —Scenarios requiring no-signup instant API access
Not for
- —High-volume balance polling where per-request fees add up
- —Users who need detailed API documentation or response schema guarantees
- —Production systems requiring SLA or uptime guarantees
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/189/balance \
-H "X-PAYMENT: <x402_payment_token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge verified) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no documented request/response schema, no usage examples, and the docs pages are empty. The specific endpoint path (/api/v1/accounts/189/balance) is not listed among the provider's public API catalog, making its purpose unclear.
Warnings
- —No OpenAPI or schema documentation available
- —Docs, pricing, and README pages return only a wallet-connect prompt with no content
- —This specific endpoint (/api/v1/accounts/189/balance) is not listed in the provider's public API catalog
- —Response format and fields are completely undocumented
- —The hardcoded account ID '189' in the path suggests this may be a single-account resource, not a general-purpose API
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (USD Coin, 6 decimals = $0.02) on the Base networkhttps://lowpaymentfee.com/api/v1/accounts/189/balance
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com