Query API3 token wallet balance on Base via x402 micropayment at $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns the wallet balance for the API3 token. It is part of a broader platform offering pay-per-request APIs across data analytics, AI/ML, finance/Web3, and infrastructure categories, all settled via the x402 protocol on the Base network using USDC.
The specific endpoint `/api/v1/wallet/API3/balance` accepts POST requests and charges a maximum of $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is made inline via the X-PAYMENT header — no API keys, accounts, or rate limits are required. The x402 challenge was confirmed live, returning a proper 402 response with version 1 of the protocol.
The platform advertises a uniform $0.02/request pricing across all its endpoints. Documentation pages (docs, pricing, README) appear to require wallet connection and contain no additional readable content, so details about request/response schemas beyond what the x402 challenge provides are unavailable. The endpoint likely returns a JSON object with the API3 token balance for a specified wallet address, but the exact input parameters and response shape are not documented in the crawled material.
Capabilities
Use cases
- —Checking API3 token balance for a given wallet address on-chain
- —Integrating real-time API3 balance data into a portfolio tracker or dashboard
- —Automated agents querying token holdings as part of a DeFi workflow
Fit
Best for
- —Developers needing quick, keyless access to API3 token balances
- —AI agents that can settle x402 micropayments on Base
- —Applications requiring low-cost, per-request crypto balance lookups
Not for
- —Bulk historical balance queries across many tokens (single-token endpoint)
- —Users who cannot settle USDC payments on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/wallet/API3/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{"address": "0xYourWalletAddress"}'Example
Request
{
"address": "0x1234567890abcdef1234567890abcdef12345678"
}Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no documented request/response format, and all docs pages require wallet connection with no readable content. The request body and response shape are inferred, not confirmed.
Warnings
- —No API documentation available — docs, pricing, and README pages all require wallet connection and return no content.
- —Request and response schemas are entirely inferred; no OpenAPI or example payloads were found.
- —The endpoint path suggests API3 token balance but the existing title/description is generic 'Premium API Access' with no specifics.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/wallet/API3/balance
- —Platform-wide pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/wallet/API3/balance