Decorators & Modifiers

Transform tool schemas and execution behavior with decorators

Composio provides powerful decorators to modify tool schemas and execution behavior.

Schema Modifiers

Transform tool schemas before they’re used:

from composio import Composio, schema_modifier

composio = Composio()

@schema_modifier(tools=["GITHUB_CREATE_ISSUE"])
def modify_schema(tool: str, toolkit: str, schema):
    # Customize the schema
    schema.description = f"Enhanced: {schema.description}"
    return schema

# Apply modifier when getting tools
tools = composio.tools.get(
    user_id="default",
    toolkits=["github"],
    modifiers=[modify_schema]
)

Before Execute

Modify tool parameters before execution:

from composio import before_execute

@before_execute(tools=["GITHUB_CREATE_ISSUE"])
def log_execution(tool: str, toolkit: str, params):
    print(f"Executing {tool} with {params['arguments']}")
    # Modify parameters
    params['arguments']['labels'] = ['automated']
    return params

# Apply when executing
result = composio.tools.execute(
    slug="GITHUB_CREATE_ISSUE",
    arguments={...},
    modifiers=[log_execution]
)

After Execute

Transform tool execution results:

from composio import after_execute

@after_execute(tools=["GITHUB_CREATE_ISSUE"])
def process_result(tool: str, toolkit: str, response):
    # Add metadata
    response['data']['processed_at'] = datetime.now().isoformat()
    return response

result = composio.tools.execute(
    slug="GITHUB_CREATE_ISSUE",
    arguments={...},
    modifiers=[process_result]
)

Apply to All Tools

# Apply to all tools in toolkit
@schema_modifier(toolkits=["github"])
def modify_all_github(tool: str, toolkit: str, schema):
    return schema

# Apply to all tools
@before_execute
def log_all(tool: str, toolkit: str, params):
    print(f"Executing {tool}")
    return params

Combining Modifiers

tools = composio.tools.get(
    user_id="default",
    toolkits=["github"],
    modifiers=[
        schema_modifier1,
        schema_modifier2,
        before_execute1
    ]
)

Complete Example

from composio import (
    Composio,
    schema_modifier,
    before_execute,
    after_execute
)
import logging

composio = Composio()
logger = logging.getLogger(__name__)

@schema_modifier(toolkits=["github"])
def enhance_github_tools(tool: str, toolkit: str, schema):
    """Add custom metadata to GitHub tools"""
    schema.description = f"[GitHub] {schema.description}"
    return schema

@before_execute(toolkits=["github"])
def log_execution(tool: str, toolkit: str, params):
    """Log all GitHub tool executions"""
    logger.info(f"Executing {tool}")
    logger.debug(f"Arguments: {params['arguments']}")
    return params

@after_execute(toolkits=["github"])
def add_metadata(tool: str, toolkit: str, response):
    """Add execution metadata"""
    if response['successful']:
        response['data']['_meta'] = {
            'tool': tool,
            'toolkit': toolkit
        }
    return response

# Use modifiers
tools = composio.tools.get(
    user_id="default",
    toolkits=["github"],
    modifiers=[enhance_github_tools]
)

result = composio.tools.execute(
    slug="GITHUB_CREATE_ISSUE",
    arguments={...},
    modifiers=[log_execution, add_metadata]
)