Check USDT wallet balance via x402 micropayment on Base network for $0.02 per request.
What it does
This endpoint at lowpaymentfee.com provides a USDT wallet balance lookup accessible via the x402 payment protocol. It is part of a broader suite of pay-per-call APIs covering data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities, all priced at $0.02 per request settled in USDC on the Base network.
The specific endpoint `/api/v1/wallet/USDT/balance` accepts POST requests and returns JSON. Payment is handled inline via the x402 protocol: callers attach an `X-PAYMENT` header containing a signed payment facilitator token. The challenge advertises a max amount of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. No API keys or rate limits are imposed; access is gated solely by micropayment.
Documentation on the site is minimal — the docs, pricing, and API pages all resolve to a wallet-connect prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema beyond the x402 outputSchema stub, and no example payloads. The endpoint is confirmed live (returns a proper 402 challenge).
Capabilities
Use cases
- —Querying a USDT wallet balance programmatically without needing an API key
- —Integrating wallet balance checks into autonomous agent workflows that settle payments on-chain
- —Building dashboards that pull real-time USDT balances via micropayment-gated calls
Fit
Best for
- —Agents or bots that need on-demand USDT balance data without subscription overhead
- —Developers prototyping x402-based payment flows on Base
- —Low-volume, pay-as-you-go wallet balance lookups
Not for
- —High-frequency trading systems needing sub-second latency guarantees (no SLA documented)
- —Users who need detailed transaction history or multi-token portfolio views
- —Anyone without a Base-network USDC wallet to fund requests
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/wallet/USDT/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed_x402_token>" \
-d '{"address": "0xYourWalletAddress"}'Example
Request
{
"address": "0x1234567890abcdef1234567890abcdef12345678"
}Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI spec, no documented request/response schema, no examples, and the site's docs pages are empty wallet-connect stubs. The actual behavior of the balance endpoint is entirely inferred from its URL path.
Warnings
- —No OpenAPI or formal schema available — request and response formats are unknown
- —Documentation pages (/docs, /pricing, /api) contain no usable content
- —The example request JSON is inferred from the endpoint path; actual required fields are undocumented
- —No SLA, rate-limit, or uptime guarantees documented
Citations
- —Endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/wallet/USDT/balance
- —All APIs on the platform are priced at $0.02 per request with no API keys or rate limitshttps://lowpaymentfee.com
- —Payment asset is USDC at contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/wallet/USDT/balance