Check wallet balance by WIF key via x402 micropayment on Base network for $0.02/request.
What it does
This endpoint at lowpaymentfee.com accepts a POST request with a WIF (Wallet Import Format) private key and returns the associated wallet balance. It is part of a broader suite of pay-per-call APIs offered by lowpaymentfee.com, all settled via the x402 protocol on the Base network using USDC.
The x402 challenge confirms the endpoint is live and charges a maximum of 20,000 base units of USDC (0.02 USD per request, since USDC uses 6 decimals). Payment is made via the x402 "exact" scheme to the specified payTo address. There are no API keys, no rate limits, and no subscription commitments — each call is individually paid for at the time of request.
The provider's landing page lists many other endpoints across data/analytics, AI/ML, finance/Web3, and infrastructure categories, all at the same $0.02 price point. However, the specific endpoint cataloged here is `/api/v1/wallet/WIF/balance`, which falls under crypto/wallet utility. Documentation beyond the landing page is essentially empty (all doc pages just show "Connect wallet"), so the exact request body schema and response format are unknown.
Capabilities
Use cases
- —Checking the balance of a wallet given its WIF private key
- —Programmatic balance verification before initiating transactions
- —Agent-driven portfolio monitoring across wallets
Fit
Best for
- —Developers needing quick, keyless wallet balance lookups
- —AI agents that need to verify crypto wallet balances on-the-fly
- —Pay-per-use access without subscription overhead
Not for
- —Bulk or high-frequency balance polling (no documented batch endpoint)
- —Users who need detailed transaction history rather than just a balance
- —Anyone uncomfortable submitting a WIF private key to a third-party API
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/wallet/WIF/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>" \
-d '{"wif": "<your_WIF_key>"}'Example
Request
{
"wif": "5HueCGU8rMjxEXxiPuD5BDku4MkFqeZyd4dZ1jvhTVqvbTLvyTJ"
}Endpoint
Quality
The x402 challenge is live and confirms pricing and network, but there is zero documentation on request/response schemas. All doc/pricing/API pages return only 'Connect wallet' with no useful content. The exact behavior and response format of this endpoint must be inferred entirely from the URL path.
Warnings
- —Submitting a WIF private key to a third-party API is a significant security risk — the server could extract funds from the wallet.
- —No documentation exists beyond the landing page; all linked doc pages are empty stubs showing only 'Connect wallet'.
- —Request body schema and response format are completely undocumented; the example request is inferred from the URL path.
- —The provider lists many endpoints but none appear to have detailed documentation.
Citations
- —The endpoint returns HTTP 402 with x402 version 1 challenge, confirming it is live.https://lowpaymentfee.com/api/v1/wallet/WIF/balance
- —Price is 20,000 base units of USDC (USD Coin, 6 decimals) = $0.02 per request on Base network.https://lowpaymentfee.com/api/v1/wallet/WIF/balance
- —The provider advertises $0.02/request, no API keys, no rate limits, instant access, Base network.https://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) all render only 'Connect wallet' with no substantive content.https://lowpaymentfee.com/docs