Tools / Crypto & Base
Balance Check $0.001 / call
ETH and USDC/ERC-20 balance on Base.
GET /v1/balanceReturns the ETH balance and USDC (or any ERC-20) balance for an address on Base. Pre-flight funding checks before a payment.
Parameters
address required | EVM address to check |
token | 'usdc' (default) or a contract address |
Example
macOS / Linuxcurl -s "https://quartermaster.surewhynot.app/v1/balance?address=0xc2a36e22ecbf353086cf83e7beea78bc28a64083"curl.exe -s "https://quartermaster.surewhynot.app/v1/balance?address=0xc2a36e22ecbf353086cf83e7beea78bc28a64083"Unpaid, these return 402 Payment Required with the payment details in the header (add -i to see them). curl.exe ships with Windows 10+ and works in cmd and both PowerShell versions. To actually pay, use an x402 client (see Connect) or call it as the MCP tool. Cost: $0.001 per call.
FAQ
Which token by default?
USDC on Base. Pass any ERC-20 contract address to check a different token.
How do I pay for this endpoint?
Call it with no payment and you receive HTTP 402 with machine-readable payment requirements. Attach a USDC payment on Base with any x402 client (for example @x402/fetch) and retry — the whole loop is two requests. This call costs $0.001 in USDC.
Do I need an account or API key?
No. There are no accounts, logins, or API keys anywhere in Quartermaster. Payment is per call over the x402 protocol; your wallet is your identity.
Can I call this as an MCP tool instead?
Yes. Quartermaster is also an MCP server at /mcp, so any MCP client (Claude Code, Claude.ai, Cursor) can mount this tool. See /connect for setup.