# L6b: Cost Optimization

**Module**: M6 Economics  
**Files**: starter.py, solution.py

## Objective

Profile a session, find savings, implement cascade routing.

## Concepts

Refer to the corresponding module for full concept explanations.

## Starter

```bash
cd course/labs/l6-cost-optimization/
# Open starter file and fill in the TODOs
```

## Checkpoints

1. Define model cost profiles (input/output $/M tokens)
2. Calculate all-Opus session cost
3. Implement cascade routing map (Flash/Sonnet/Opus by task)
4. Calculate savings percentage

## Solution

Compare against the solution file after attempting the starter.