feat(qw2): LoopDetector composite (screen_static + action_repeat + retry)

Module isolé, 3 signaux indépendants :
- screen_static : CLIP similarity > 0.99 sur N captures consécutives
- action_repeat : N actions identiques (type+coords)
- retry_threshold : retried_actions >= seuil

Premier signal positif → LoopVerdict.detected=True (caller responsable de
la bascule en paused_need_help).

Configurable env vars : RPA_LOOP_DETECTOR_ENABLED (kill-switch),
RPA_LOOP_SCREEN_STATIC_N/THRESHOLD, RPA_LOOP_ACTION_REPEAT_N,
RPA_LOOP_RETRY_THRESHOLD.

Tests : 8 cas (chaque signal isolé, kill-switch, embedder absent, exception).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Dom
2026-05-05 23:09:43 +02:00
parent 2d71e2a249
commit 2a51a844b9
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# agent_v0/server_v1/loop_detector.py
"""LoopDetector composite — détection de stagnation de Léa pendant un replay (QW2).
Trois signaux indépendants :
- screen_static : N captures consécutives avec CLIP similarity > seuil
- action_repeat : N actions consécutives identiques (type + coords)
- retry_threshold : nombre de retries cumulés >= seuil
Un seul signal positif → verdict.detected=True. Le serveur bascule alors le
replay en paused_need_help avec pause_reason explicite.
Désactivable via env var RPA_LOOP_DETECTOR_ENABLED=0.
"""
import logging
import os
from dataclasses import dataclass, field
from typing import Any, Dict, List, Optional
logger = logging.getLogger(__name__)
@dataclass
class LoopVerdict:
detected: bool = False
reason: str = ""
signal: str = "" # "screen_static" | "action_repeat" | "retry_threshold" | ""
evidence: Dict[str, Any] = field(default_factory=dict)
def _env_int(name: str, default: int) -> int:
try:
return int(os.environ.get(name, default))
except (TypeError, ValueError):
return default
def _env_float(name: str, default: float) -> float:
try:
return float(os.environ.get(name, default))
except (TypeError, ValueError):
return default
def _env_bool_enabled(name: str) -> bool:
val = os.environ.get(name, "1").strip().lower()
return val not in ("0", "false", "no", "off", "")
def _cosine_similarity(a, b) -> float:
"""Similarité cosine entre deux vecteurs (listes ou np.array). Robuste vecteur nul."""
import numpy as np
av = np.asarray(a, dtype=np.float32).flatten()
bv = np.asarray(b, dtype=np.float32).flatten()
na, nb = float(np.linalg.norm(av)), float(np.linalg.norm(bv))
if na < 1e-8 or nb < 1e-8:
return 0.0
return float(np.dot(av, bv) / (na * nb))
class LoopDetector:
def __init__(self, clip_embedder=None):
self.clip_embedder = clip_embedder
def evaluate(
self,
state: Dict[str, Any],
screenshots: List[Any],
actions: List[Dict[str, Any]],
) -> LoopVerdict:
"""Évalue les 3 signaux. Retourne le premier déclenché.
Args:
state: replay_state (utilisé pour retried_actions)
screenshots: anneau d'embeddings CLIP (les N derniers)
actions: anneau des N dernières actions exécutées
"""
if not _env_bool_enabled("RPA_LOOP_DETECTOR_ENABLED"):
return LoopVerdict(detected=False)
# Signal A : screen_static
verdict = self._check_screen_static(screenshots)
if verdict.detected:
return verdict
# Signal B : action_repeat
verdict = self._check_action_repeat(actions)
if verdict.detected:
return verdict
# Signal C : retry_threshold
verdict = self._check_retry_threshold(state)
if verdict.detected:
return verdict
return LoopVerdict(detected=False)
def _check_screen_static(self, screenshots: List[Any]) -> LoopVerdict:
n_required = _env_int("RPA_LOOP_SCREEN_STATIC_N", 4)
threshold = _env_float("RPA_LOOP_SCREEN_STATIC_THRESHOLD", 0.99)
if self.clip_embedder is None or len(screenshots) < n_required:
return LoopVerdict()
try:
recent = screenshots[-n_required:]
# Embed chaque capture via le CLIP embedder (peut lever)
embeddings = [self.clip_embedder.embed_image(img) for img in recent]
sims = [_cosine_similarity(embeddings[i], embeddings[i + 1])
for i in range(len(embeddings) - 1)]
min_sim = min(sims)
if min_sim > threshold:
return LoopVerdict(
detected=True,
reason="loop_detected",
signal="screen_static",
evidence={"min_similarity": round(min_sim, 4),
"n_captures": n_required,
"threshold": threshold},
)
except Exception as e:
logger.warning("LoopDetector signal_A erreur (%s) — signal inerte ce tick", e)
return LoopVerdict()
def _check_action_repeat(self, actions: List[Dict[str, Any]]) -> LoopVerdict:
n_required = _env_int("RPA_LOOP_ACTION_REPEAT_N", 3)
if len(actions) < n_required:
return LoopVerdict()
recent = actions[-n_required:]
def _signature(a: Dict[str, Any]) -> tuple:
return (a.get("type"), a.get("x_pct"), a.get("y_pct"))
sigs = [_signature(a) for a in recent]
if all(s == sigs[0] for s in sigs):
return LoopVerdict(
detected=True,
reason="loop_detected",
signal="action_repeat",
evidence={"signature": sigs[0], "count": n_required},
)
return LoopVerdict()
def _check_retry_threshold(self, state: Dict[str, Any]) -> LoopVerdict:
threshold = _env_int("RPA_LOOP_RETRY_THRESHOLD", 3)
retried = int(state.get("retried_actions", 0))
if retried >= threshold:
return LoopVerdict(
detected=True,
reason="loop_detected",
signal="retry_threshold",
evidence={"retried_actions": retried, "threshold": threshold},
)
return LoopVerdict()

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# tests/unit/test_loop_detector.py
"""Tests unitaires pour LoopDetector composite (QW2)."""
import os
import pytest
from unittest.mock import MagicMock
from agent_v0.server_v1.loop_detector import LoopDetector, LoopVerdict
@pytest.fixture
def detector():
"""LoopDetector avec embedder mocké (signal A toujours dispo)."""
embedder = MagicMock()
# Par défaut : 4 embeddings tous identiques → similarity 1.0
embedder.embed_image.return_value = [1.0, 0.0, 0.0]
return LoopDetector(clip_embedder=embedder)
def _state(retried=0, n_screenshots=0, n_actions=0):
return {
"retried_actions": retried,
"_screenshot_history": [[1.0, 0.0, 0.0]] * n_screenshots,
"_action_history": [{"type": "click", "x_pct": 0.5, "y_pct": 0.5}] * n_actions,
}
def test_screen_static_triggers_when_n_identical_embeddings(detector):
"""Signal A : 4 captures identiques (similarity > 0.99) → detected."""
state = _state(n_screenshots=4)
verdict = detector.evaluate(state, screenshots=state["_screenshot_history"], actions=[])
assert verdict.detected is True
assert verdict.signal == "screen_static"
def test_screen_static_skipped_when_history_too_short(detector):
"""Signal A : moins de N captures → pas de détection."""
state = _state(n_screenshots=2)
verdict = detector.evaluate(state, screenshots=state["_screenshot_history"], actions=[])
# Si seul A pourrait déclencher mais skip, et B/C pas remplis : detected=False
assert verdict.detected is False
def test_action_repeat_triggers_when_n_identical_actions(detector):
"""Signal B : 3 actions consécutives identiques → detected."""
state = _state(n_actions=3)
verdict = detector.evaluate(state, screenshots=[], actions=state["_action_history"])
assert verdict.detected is True
assert verdict.signal == "action_repeat"
def test_action_repeat_skipped_when_actions_differ(detector):
"""Signal B : actions différentes → pas de détection."""
actions = [
{"type": "click", "x_pct": 0.1, "y_pct": 0.1},
{"type": "click", "x_pct": 0.2, "y_pct": 0.2},
{"type": "click", "x_pct": 0.3, "y_pct": 0.3},
]
verdict = detector.evaluate(_state(), screenshots=[], actions=actions)
assert verdict.detected is False
def test_retry_threshold_triggers_at_3(detector):
"""Signal C : retried_actions >= 3 → detected."""
state = _state(retried=3)
verdict = detector.evaluate(state, screenshots=[], actions=[])
assert verdict.detected is True
assert verdict.signal == "retry_threshold"
def test_kill_switch_disables_all_signals(monkeypatch, detector):
"""Si RPA_LOOP_DETECTOR_ENABLED=0 → toujours detected=False."""
monkeypatch.setenv("RPA_LOOP_DETECTOR_ENABLED", "0")
state = _state(retried=10, n_screenshots=10, n_actions=10)
verdict = detector.evaluate(state, screenshots=state["_screenshot_history"],
actions=state["_action_history"])
assert verdict.detected is False
def test_embedder_unavailable_skips_signal_A_continues_others():
"""Si CLIP embedder None → signal A skip, B et C continuent."""
detector = LoopDetector(clip_embedder=None)
# Trigger signal C
state = _state(retried=3)
verdict = detector.evaluate(state, screenshots=[], actions=[])
assert verdict.detected is True
assert verdict.signal == "retry_threshold"
def test_embedder_exception_does_not_crash(detector):
"""Si embed_image lève une exception → log + verdict detected=False."""
detector.clip_embedder.embed_image.side_effect = RuntimeError("CUDA OOM")
state = _state(n_screenshots=4)
# Ne doit PAS lever : signal A devient inerte
verdict = detector.evaluate(state, screenshots=state["_screenshot_history"], actions=[])
# Signal A inerte, B/C pas remplis → detected False
assert verdict.detected is False