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Swarms provides a comprehensive tool system that allows agents to execute custom functions, interact with APIs, and perform specialized tasks. The framework supports multiple tool integration patterns with automatic schema generation and validation.

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Overview

The Swarms tool system provides:
  • Automatic Schema Generation: Convert Python functions to OpenAI-compatible tool schemas
  • Type Safety: Full type hint support with validation
  • Tool Registry: Centralized management of available tools
  • Pydantic Integration: Use Pydantic models for structured tool inputs
  • Batch Execution: Execute multiple tools concurrently
  • Error Handling: Comprehensive error handling and validation

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Quick Start

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Basic Tool Usage

Add a simple function as a tool: 
from swarms import Agent

def get_weather(location: str, units: str = "celsius") -> str:
    """
    Get the weather for a location.
    
    Args:
        location: The city or location to get weather for
        units: Temperature units (celsius or fahrenheit)
    
    Returns:
        Weather information as a string
    """
    # Your weather API logic here
    return f"The weather in {location} is 72°{units[0].upper()}"

# Create agent with the tool
agent = Agent(
    agent_name="Weather-Agent",
    model_name="gpt-4o",
    tools=[get_weather],
    max_loops=1,
)

result = agent.run("What's the weather in San Francisco?")
Tools must have:
  1. Type hints for all parameters
  2. A docstring describing the function
  3. Return type annotation

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BaseTool Class

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Core Tool Management

The BaseTool class provides comprehensive tool management: 
from swarms.tools import BaseTool

def calculate_roi(investment: float, return_amount: float) -> float:
    """
    Calculate return on investment percentage.
    
    Args:
        investment: Initial investment amount
        return_amount: Final return amount
        
    Returns:
        ROI as a percentage
    """
    return ((return_amount - investment) / investment) * 100

# Create tool manager
tool_manager = BaseTool(
    tools=[calculate_roi],
    verbose=True,
    autocheck=True,
)

# Convert function to OpenAI schema
schema = tool_manager.func_to_dict(calculate_roi)
print(schema)

​
Multiple Tools

Manage multiple tools with validation: 
from swarms.tools import BaseTool
from typing import List

def search_database(query: str, limit: int = 10) -> List[dict]:
    """
    Search the database for records.
    
    Args:
        query: Search query string
        limit: Maximum number of results
        
    Returns:
        List of matching records
    """
    return [{"id": 1, "title": "Result 1"}]

def send_email(to: str, subject: str, body: str) -> bool:
    """
    Send an email.
    
    Args:
        to: Recipient email address
        subject: Email subject
        body: Email body content
        
    Returns:
        True if sent successfully
    """
    return True

def analyze_sentiment(text: str) -> dict:
    """
    Analyze sentiment of text.
    
    Args:
        text: Text to analyze
        
    Returns:
        Sentiment analysis results
    """
    return {"sentiment": "positive", "score": 0.95}

# Create tool manager with multiple tools
tool_manager = BaseTool(
    tools=[search_database, send_email, analyze_sentiment],
    verbose=True,
)

# Convert all tools to OpenAI schema
tool_manager.convert_funcs_into_tools()

# Access the function map
print(tool_manager.function_map.keys())
# Output: dict_keys(['search_database', 'send_email', 'analyze_sentiment'])

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Pydantic Model Tools

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Structured Tool Inputs

Use Pydantic models for complex tool schemas: 
from swarms.tools import BaseTool
from pydantic import BaseModel, Field
from typing import List

class UserProfile(BaseModel):
    """User profile information."""
    name: str = Field(..., description="User's full name")
    email: str = Field(..., description="User's email address")
    age: int = Field(..., ge=0, le=150, description="User's age")
    interests: List[str] = Field(
        default_factory=list,
        description="List of user interests"
    )

class SearchQuery(BaseModel):
    """Database search parameters."""
    query: str = Field(..., description="Search query string")
    filters: dict = Field(
        default_factory=dict,
        description="Optional filters"
    )
    limit: int = Field(10, ge=1, le=100, description="Result limit")

# Create tool manager with Pydantic models
tool_manager = BaseTool(
    base_models=[UserProfile, SearchQuery],
    verbose=True,
)

# Convert to OpenAI schema
user_schema = tool_manager.base_model_to_dict(UserProfile)
search_schema = tool_manager.base_model_to_dict(SearchQuery)

print(user_schema)
print(search_schema)

​
Multiple Pydantic Models

from swarms.tools import BaseTool
from pydantic import BaseModel

class Model1(BaseModel):
    """First model."""
    field1: str
    field2: int

class Model2(BaseModel):
    """Second model."""
    field_a: str
    field_b: bool

tool_manager = BaseTool(
    base_models=[Model1, Model2],
)

# Convert all models to schemas
schemas = tool_manager.multi_base_models_to_dict(
    base_models=[Model1, Model2],
    output_str=False,
)

print(f"Generated {len(schemas)} schemas")

​
Tool Registry

​
Centralized Tool Management

Use the ToolStorage registry for managing tools: 
from swarms.tools import ToolStorage, tool_registry

# Create tool storage
storage = ToolStorage(
    name="My Tool Registry",
    description="A registry for my custom tools",
    verbose=True,
)

# Register tools using decorator
@tool_registry(storage)
def calculate_tax(amount: float, rate: float) -> float:
    """
    Calculate tax amount.
    
    Args:
        amount: Base amount
        rate: Tax rate as decimal (e.g., 0.08 for 8%)
        
    Returns:
        Tax amount
    """
    return amount * rate

@tool_registry(storage)
def format_currency(amount: float, currency: str = "USD") -> str:
    """
    Format amount as currency.
    
    Args:
        amount: Monetary amount
        currency: Currency code (USD, EUR, etc.)
        
    Returns:
        Formatted currency string
    """
    return f"{currency} {amount:.2f}"

# List all registered tools
print(storage.list_tools())

# Get a specific tool
tax_tool = storage.get_tool("calculate_tax")
result = tax_tool(100.0, 0.08)
print(f"Tax: ${result}")

​
Batch Tool Registration

from swarms.tools import ToolStorage

storage = ToolStorage(
    name="Batch Registry",
    description="Registry with batch-loaded tools",
)

def tool1(x: int) -> int:
    """Tool 1."""
    return x * 2

def tool2(x: int) -> int:
    """Tool 2."""
    return x + 10

def tool3(x: int) -> int:
    """Tool 3."""
    return x ** 2

# Add multiple tools at once
storage.add_many_tools([tool1, tool2, tool3])

print(storage.list_tools())

​
Tool Execution

​
Execute Tools Dynamically

from swarms.tools import BaseTool
import json

def process_data(data: str, format: str = "json") -> dict:
    """
    Process data in various formats.
    
    Args:
        data: Input data string
        format: Output format (json, xml, etc.)
        
    Returns:
        Processed data
    """
    return {"processed": data, "format": format}

tool_manager = BaseTool(
    tools=[process_data],
    verbose=True,
)

tool_manager.convert_funcs_into_tools()

# Execute tool with JSON response
tool_call = json.dumps({
    "name": "process_data",
    "parameters": {
        "data": "sample data",
        "format": "json"
    }
})

result = tool_manager.execute_tool_from_text(tool_call)
print(result)

​
Execute by Name

from swarms.tools import BaseTool

tool_manager = BaseTool(
    tools=[process_data],
)

tool_manager.convert_funcs_into_tools()

# Execute specific tool by name
result = tool_manager.execute_tool_by_name(
    tool_name="process_data",
    response='{"data": "test", "format": "json"}',
)

​
Advanced Patterns

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Tool Validation

Validate tools before execution: 
from swarms.tools import BaseTool

def my_tool(x: int, y: int) -> int:
    """
    A properly documented tool.
    
    Args:
        x: First number
        y: Second number
        
    Returns:
        Sum of x and y
    """
    return x + y

tool_manager = BaseTool(verbose=True)

# Check documentation
has_docs = tool_manager.check_func_if_have_docs(my_tool)
print(f"Has documentation: {has_docs}")

# Check type hints
has_hints = tool_manager.check_func_if_have_type_hints(my_tool)
print(f"Has type hints: {has_hints}")

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Dynamic Tool Generation

from swarms.tools import BaseTool

class DynamicToolManager:
    def __init__(self):
        self.tool_manager = BaseTool(verbose=True)
        
    def create_tool_from_api(self, api_name: str) -> callable:
        """Generate a tool from API specification."""
        def api_tool(endpoint: str, params: dict) -> dict:
            f"""
            Call {api_name} API.
            
            Args:
                endpoint: API endpoint
                params: Request parameters
                
            Returns:
                API response
            """
            # API call logic here
            return {"api": api_name, "endpoint": endpoint}
        
        return api_tool
    
    def register_api_tools(self, apis: list[str]):
        """Register tools for multiple APIs."""
        tools = [self.create_tool_from_api(api) for api in apis]
        self.tool_manager.tools = tools
        self.tool_manager.convert_funcs_into_tools()
        
manager = DynamicToolManager()
manager.register_api_tools(["stripe", "sendgrid", "twilio"])

​
Tool Composition

Combine multiple tools into workflows: 
from swarms import Agent
from typing import Dict, List

def fetch_data(source: str) -> Dict:
    """Fetch data from source."""
    return {"data": f"Data from {source}"}

def transform_data(data: Dict, format: str) -> Dict:
    """Transform data format."""
    return {"transformed": data, "format": format}

def save_data(data: Dict, destination: str) -> bool:
    """Save data to destination."""
    return True

# Create agent with pipeline tools
pipeline_agent = Agent(
    agent_name="Pipeline-Agent",
    model_name="gpt-4o",
    tools=[fetch_data, transform_data, save_data],
    system_prompt="Execute data pipeline: fetch, transform, and save.",
    max_loops=3,
)

result = pipeline_agent.run(
    "Fetch data from API, transform to JSON, and save to database"
)

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Best Practices

Documentation

Always include comprehensive docstrings with parameter descriptions

Type Hints

Use type hints for all function parameters and return values

Error Handling

Implement robust error handling in your tools

Validation

Validate inputs using Pydantic models for complex schemas

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Common Patterns

​
API Integration Tool

import httpx
from typing import Dict, Optional

def call_api(
    url: str,
    method: str = "GET",
    headers: Optional[Dict] = None,
    params: Optional[Dict] = None,
) -> Dict:
    """
    Make HTTP API calls.
    
    Args:
        url: API endpoint URL
        method: HTTP method (GET, POST, etc.)
        headers: Optional HTTP headers
        params: Optional query parameters or body
        
    Returns:
        API response as dictionary
    """
    with httpx.Client() as client:
        response = client.request(
            method=method,
            url=url,
            headers=headers or {},
            params=params or {},
        )
        return response.json()

​
Database Tool

from typing import List, Dict, Optional

def query_database(
    query: str,
    parameters: Optional[Dict] = None,
    limit: int = 100,
) -> List[Dict]:
    """
    Execute database query.
    
    Args:
        query: SQL query string
        parameters: Query parameters
        limit: Maximum results to return
        
    Returns:
        Query results as list of dictionaries
    """
    # Database logic here
    return [{"id": 1, "name": "Example"}]

​
File Processing Tool

from pathlib import Path
from typing import Union

def process_file(
    file_path: str,
    operation: str,
    output_path: Optional[str] = None,
) -> str:
    """
    Process files with various operations.
    
    Args:
        file_path: Path to input file
        operation: Operation to perform (read, write, convert, etc.)
        output_path: Optional output file path
        
    Returns:
        Operation result message
    """
    path = Path(file_path)
    
    if operation == "read":
        return path.read_text()
    elif operation == "convert":
        # Conversion logic
        return f"Converted {file_path} to {output_path}"
    
    return "Operation completed"

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Troubleshooting

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Common Issues

Missing Type Hints 
# ❌ Wrong - no type hints
def bad_tool(x, y):
    return x + y

# ✅ Correct - with type hints
def good_tool(x: int, y: int) -> int:
    """Add two numbers."""
    return x + y
Missing Documentation 
# ❌ Wrong - no docstring
def bad_tool(x: int) -> int:
    return x * 2

# ✅ Correct - with docstring
def good_tool(x: int) -> int:
    """
    Double the input value.
    
    Args:
        x: Input value
        
    Returns:
        Doubled value
    """
    return x * 2

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