> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upsonic.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Sequential & Parallel Run

> Control whether a tool can be executed in parallel with others

## Overview

Control whether a tool can be executed in parallel with others.

## Usage

```python theme={null}
from upsonic.tools import tool

@tool(sequential=True)
def database_transaction(operation: str, data: str) -> str:
    """
    Execute a database transaction that must run sequentially.

    Args:
        operation: Transaction type
        data: Transaction data

    Returns:
        Transaction result
    """
    return f"Transaction {operation} completed with data: {data}"
```

## Parameters

* `sequential` (bool): If True, tool must execute sequentially (no parallelization)