Per-Step Critic Features + Rule-Based Step Scorer

Scoring an agent’s step needs the evidence in one place — what the action was, what changed, whether it landed on target, whether the declared postcondition held. trajectory_eval scores a finished whole trajectory against a static rubric and has no per-step evidence; agent_trace emits OTel spans (tokens / latency), not decision quality; agent_replay persists {obs, action, result} but does no scoring. critic_features is the missing per-step layer: it composes action_effect (did it do anything, where), observation_delta (how much changed) and postcondition (did the expected outcome hold) into one compact record, and ships a deterministic rule-based scorer so the feature works fully headless — leaving the optional LLM-as-judge to the integrator.

Pure-stdlib; composes existing pure modules; deterministic and unit-testable with no device. Imports no PySide6.

Headless API

from je_auto_control import (build_critic_record, score_step_rule_based,
                             to_judge_prompt)

record = build_critic_record({"type": "click", "x": 480, "y": 260},
                             before_elements, after_elements,
                             postcondition={"appears": {"role": "dialog"}})
score = score_step_rule_based(record)
# {"outcome": True, "process_score": 1.0, "reasons": [...]}

prompt = to_judge_prompt(record)   # compact text for an LLM-as-judge

build_critic_record returns {action, effect, delta_counts} plus a postcondition report when a spec is given. score_step_rule_based returns {outcome, process_score, reasons} — outcome is a binary success (the action did something and any postcondition held), process_score is a 0..1 quality from the effect class (halved if the postcondition failed). to_judge_prompt renders the record for an external judge.

Executor commands

AC_build_critic_record (action / before / after / postcondition / radius → the record) and AC_score_step (record → {outcome, process_score, reasons}). They are exposed as the MCP tools ac_build_critic_record / ac_score_step (read-only) and as the Script Builder commands Build Critic Record / Score Step (rule-based) under Native UI.