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/111/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.
The broader lowpaymentfee.com platform advertises a suite of pay-per-call 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, settled in USDC on Base via the x402 protocol. The platform advertises no API keys, no rate limits, and instant access.
However, documentation is essentially nonexistent — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed description of what the account balance endpoint actually returns or what inputs it expects beyond a POST request. The endpoint is confirmed live (returns a proper 402 challenge), but the lack of documentation makes it difficult to assess the actual utility or data quality of the response.
Capabilities
Use cases
- —Querying account balance information via a pay-per-call model without API key registration
- —Integrating x402-compatible agents with low-cost financial data endpoints
- —Testing x402 protocol payment flows on Base network
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —Agents that need keyless, pay-per-call API access on Base
- —Low-cost per-request financial data lookups
Not for
- —Production use cases requiring documented request/response schemas
- —High-volume analytics where per-call pricing adds up quickly
- —Users who need detailed API documentation before integration
Quick start
# The endpoint requires an x402 X-PAYMENT header with USDC on Base.
# Using curl to see the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/accounts/111/balance
# Returns 402 with x402 payment challenge.
# Use an x402-compatible client to attach payment automatically.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but documentation is effectively absent — all doc pages show only 'Connect wallet'. No OpenAPI schema, no request/response examples, and no description of what the balance endpoint actually returns. The listing is essentially a stub with confirmed liveness.
Warnings
- —Documentation pages (docs, API, pricing, README) all render only 'Connect wallet' with no actual content
- —No OpenAPI or schema available — request format and response structure are unknown
- —The specific endpoint path '/api/v1/accounts/111/balance' with a hardcoded account ID '111' is unusual and may be a demo or placeholder
- —No information on what data source backs the account balance response
Citations
- —The endpoint returns a 402 challenge requiring USDC payment on Base network with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/accounts/111/balance
- —All endpoints listed at $0.02 per request with no API keys, no rate limits, instant accesshttps://lowpaymentfee.com
- —Platform offers APIs across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/accounts/111/balance