Verify Execution Logs

Use logs when the way an action was performed matters, such as pressing buttons in order or registering a particular attribute. Environment goals answer whether the world is correct; logs preserve execution evidence.

A tool verifier can return ToolResult(ok=True, logs=Log(content=button_name)). The runtime attaches the tool function name and stage ID. Despite its plural name, ToolResult.logs accepts one optional Log, not a list.

Inside a stage that stores self.button:

from magma_core.simulation.data_structures import Log

# Method inside the stage:
def verif_log_completion(self, stage_log: list[Log], full_log: list[Log]) -> int:
    if not stage_log:
        return 0
    return 1 if stage_log[-1].content == self.button else -1

This policy fails immediately on a different last log; use a different policy if your stage permits intermediate detection or retries. stage_log is local to the checkpoint; full_log includes earlier execution history.

The default combined result fails if either environment or log verification fails, succeeds if both succeed, and otherwise remains ongoing. A log-only stage can have no goals, but must override the log verifier. A text-only stage cannot combine a verification prompt with custom log verification.

For attribute changes, use Log.action and an additive stage. See attribute edits.