from vizpy import ContraPromptOptimizer, Score
 
def metric(example, prediction):
    return Score(value=0.0-1.0, is_success=True/False, feedback="...")
 
optimizer = ContraPromptOptimizer(metric=metric)
optimized = optimizer.optimize(module, train_examples)

from vizpy import PromptGradOptimizer
 
optimizer = PromptGradOptimizer(metric=metric)
optimized = optimizer.optimize(module, train_examples)

Score(
    value=0.85,        # 0.0 to 1.0
    is_success=True,   # Pass/fail
    feedback="",       # Error explanation
    error_type="",     # Error category
)