x402-gated account balance endpoint on Base, paying $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com exposes an account balance resource (`/api/v1/accounts/6/balance`) behind an x402 payment challenge. It is part of a broader platform that offers multiple API categories — data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all gated via the x402 protocol on the Base network. Each request costs $0.02 in USDC (USD Coin), settled on-chain with no API keys, no rate limits, and no commitments required.
The specific endpoint probed (`/api/v1/accounts/6/balance`) accepts POST requests and returns JSON. The x402 challenge confirms it is live, requesting a maximum of 20,000 base units of USDC (0.02 USD given 6 decimals) per call, paid to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the `exact` payment scheme. The timeout for payment settlement is 300 seconds.
Documentation on the site is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the balance endpoint actually returns. The platform lists many other endpoints across categories (sentiment analysis, text summarization, geocoding, price feeds, etc.), all at the same $0.02 price point, but none have documented schemas either. Prospective users should be aware that the actual functionality and response format of this endpoint is unverified beyond the x402 challenge metadata.
Capabilities
Use cases
- —Querying account balance data via a pay-per-request model without API key registration
- —Integrating on-chain micropayment-gated endpoints into agent workflows
- —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
- —Projects requiring on-chain USDC micropayment settlement for API calls
Not for
- —Production systems requiring well-documented API schemas and response contracts
- —Users who need free or subscription-based API access without crypto wallets
- —High-volume use cases where per-request on-chain settlement adds unacceptable latency
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/6/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is zero documentation on request parameters, response schema, or what 'account balance' actually returns. Docs pages are empty stubs. Without any schema or examples, this is effectively a stub listing.
Warnings
- —No OpenAPI spec or schema documentation available
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no content
- —The actual response format and data returned by this endpoint are completely undocumented
- —The endpoint path includes a hardcoded account ID (6); it is unclear whether other account IDs are supported or what they represent
- —Many endpoints listed on the site share the same $0.02 price but none have documented behavior
Citations
- —The endpoint returns a 402 challenge requesting 20,000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/accounts/6/balance
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/accounts/6/balance
- —All APIs are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com