Overview
This example demonstrates using Monty to analyze team expense data across multiple users. Instead of making 50+ sequential tool calls, the LLM writes a loop that processes each team member’s expenses in code.
Why This Example Matters
With traditional tool calling, analyzing expenses for a team would require:
- Call
get_team_members() → returns 5 members
- For each member:
- Call
get_expenses(user_id, quarter, category) → returns 10-15 expense items
- Call
get_custom_budget(user_id) → returns budget or null
- Process results in the LLM
This floods the context window with hundreds of expense items. With Monty:
- The loop runs in the sandbox
- Only the final summary returns to the host
- Token usage drops dramatically
The Task
Analyze Q3 travel expenses for the Engineering team and identify who exceeded their budget (standard $5,000 or custom).
Code Structure
Type Definitions
type_definitions = '''
from typing import Any
async def get_team_members(department: str) -> dict[str, Any]:
"""Get list of team members for a department.
Args:
department: The department name (e.g., "Engineering").
Returns:
Dictionary with list of team members.
"""
...
async def get_expenses(user_id: int, quarter: str, category: str) -> dict[str, Any]:
"""Get expense line items for a user.
Args:
user_id: The user's ID.
quarter: The quarter (e.g., "Q3").
category: The expense category (e.g., "travel").
Returns:
Dictionary with expense items.
"""
...
async def get_custom_budget(user_id: int) -> dict[str, Any] | None:
"""Get custom budget for a user if they have one.
Args:
user_id: The user's ID.
Returns:
Custom budget info or None if no custom budget.
"""
...
'''
The Sandbox Code
code = """
# Get Engineering team members
team_data = await get_team_members(department="Engineering")
team_members = team_data.get("members", [])
# Standard budget
STANDARD_BUDGET = 5000
# Process each team member
total_members = len(team_members)
over_budget_list = []
for member in team_members:
user_id = member.get("id")
name = member.get("name")
# Get Q3 travel expenses for this user
expenses_data = await get_expenses(user_id=user_id, quarter="Q3", category="travel")
expense_items = expenses_data.get("expenses", [])
# Sum up total expenses
total_spent = sum(item.get("amount", 0) for item in expense_items)
# Check if they exceeded standard budget
if total_spent > STANDARD_BUDGET:
# Check for custom budget
custom_budget_data = await get_custom_budget(user_id=user_id)
if custom_budget_data is not None:
budget = custom_budget_data.get("budget", STANDARD_BUDGET)
else:
budget = STANDARD_BUDGET
# Check if they exceeded their actual budget (standard or custom)
if total_spent > budget:
amount_over = total_spent - budget
over_budget_list.append({
"name": name,
"total_spent": total_spent,
"budget": budget,
"amount_over": amount_over
})
# Return the analysis
{
"total_team_members_analyzed": total_members,
"count_exceeded_budget": len(over_budget_list),
"over_budget_details": over_budget_list
}
"""
Execution
import pydantic_monty
m = pydantic_monty.Monty(
code,
inputs=['prompt'],
script_name='expense.py',
type_check=True,
type_check_stubs=type_definitions,
)
async def main():
output = await pydantic_monty.run_monty_async(
m,
inputs={'prompt': 'testing'},
external_functions={
'get_team_members': data.get_team_members,
'get_expenses': data.get_expenses,
'get_custom_budget': data.get_custom_budget,
},
)
print(output)
Example Data
Team Members
team_members = [
{'id': 1, 'name': 'Alice Chen'},
{'id': 2, 'name': 'Bob Smith'},
{'id': 3, 'name': 'Carol Jones'},
{'id': 4, 'name': 'David Kim'},
{'id': 5, 'name': 'Eve Wilson'},
]
Expense Data
Each user has 8-15 expense line items with details like:
{
'date': '2024-07-15',
'amount': 450.00,
'description': 'Flight to NYC'
}
Custom Budgets
custom_budgets = {
2: {'amount': 7000.00, 'reason': 'International travel required'},
}
Expected Output
{
"total_team_members_analyzed": 5,
"count_exceeded_budget": 2,
"over_budget_details": [
{
"name": "Carol Jones",
"total_spent": 6740.0,
"budget": 5000,
"amount_over": 1740.0
},
{
"name": "Eve Wilson",
"total_spent": 5680.0,
"budget": 5000,
"amount_over": 680.0
}
]
}
Bob Smith spent over the standard budget but has a custom budget of $7,000, so he’s not flagged as over budget.
Key Benefits
Loops in Code
The for member in team_members loop is natural in Python, but would require complex orchestration with tool calls.
Conditional Logic
The code checks if expenses exceed the standard budget, then conditionally fetches custom budgets. This would require multiple LLM round-trips with tool calling.
In-Sandbox Computation
Summing expense amounts happens in the sandbox. The LLM doesn’t need to do mental math or see every expense item.
Reduced Token Usage
Only the final summary leaves the sandbox. With tool calling, every expense item (50+ items) would flood the context.
Running the Example
uv run python examples/expense_analysis/main.py
Async Patterns
All external functions are async, and Monty handles them seamlessly:
# Multiple async calls in sequence
team_data = await get_team_members(department="Engineering")
expenses_data = await get_expenses(user_id=user_id, quarter="Q3", category="travel")
# Conditional async calls
if total_spent > STANDARD_BUDGET:
custom_budget_data = await get_custom_budget(user_id=user_id)
For parallel execution, use asyncio.gather() to fire multiple calls at once instead of awaiting each one sequentially.
Next Steps
- Explore the full source in
examples/expense_analysis/
- Try Web Scraper for browser automation
- See SQL Playground for file mounting and SQL queries
