base-token-balance

Read a live ERC-20 token balance on Base and return raw units plus best-effort token decimals/symbol metadata without signup or an API key.

Price: $0.01 USDC equivalent
Endpoint: POST /v1/base-token-balance
Network: Base mainnet · eip155:8453
Asset: USDC
MCP tool: base-token-balance
External payability: PASS · 2026-10-08T19:55:01.298Z

When an agent should use it

check token balance on Base
live Base USDC balance API for an agent
read ERC20 balance without signup

Input schema

{
  "type": "object",
  "properties": {
    "token_address": {
      "type": "string",
      "pattern": "^0x[0-9a-fA-F]{40}$"
    },
    "owner": {
      "type": "string",
      "pattern": "^0x[0-9a-fA-F]{40}$"
    }
  },
  "required": [
    "token_address",
    "owner"
  ],
  "additionalProperties": false
}

Example request

{
  "token_address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "owner": "0x0000000000000000000000000000000000000001"
}

Example output

{
  "balance_atomic": "0",
  "decimals": 6,
  "symbol": "USDC",
  "block_number": 12345678
}

x402 flow

POST /v1/base-token-balance
→ HTTP 402 + PAYMENT-REQUIRED
→ buyer authorizes locally
→ retry same request with PAYMENT-SIGNATURE
→ one governed execution + machine-readable JSON

Discovery: OpenAPI · x402 · llms.txt

A valid 402/payability probe is operational evidence, not proof of independent demand, future settlement, or semantic correctness.