# GetBaseCurrency

## Overview

GetBaseCurrency retrieves the currency designated as the organization's base currency. Returns the currency record if a base currency has been set, or null if no base currency exists.

This function supports financial reporting and default currency selection workflows.

## Business Rules

- Returns the single currency where `isBaseCurrency` is true
- At most one currency can be the base currency at any time
- Returns null if no base currency has been configured (e.g., before any currencies are created)
- Does not require any input parameters

## Process Flow

```mermaid
flowchart TD
    A[Receive request] --> B[Query Currency where isBaseCurrency = true]
    B --> C{Found?}
    C -->|Yes| D[Return base currency]
    C -->|No| E[Return null]
```

## External Dependencies

- None

## Error Scenarios

- None (returns null when no base currency is set instead of throwing)

## Test Cases

- returns base currency when set
- returns null when no base currency is set
