curl --request GET \
  --url https://api.machines.cash/partner/v1/balances \
  --header 'Authorization: Bearer <token>'

{
  "ok": true,
  "data": {
    "balances": {
      "creditLimit": 123,
      "pendingCharges": 123,
      "postedCharges": 123,
      "balanceDue": 123,
      "spendingPower": 123
    }
  },
  "summary": "<string>",
  "errors": [
    {
      "code": "invalid_request",
      "message": "missing required field",
      "field": "<string>"
    }
  ],
  "next": {
    "pollAfterMs": 1,
    "suggestedTool": "<string>",
    "suggestedArgs": {}
  }
}