diff --git a/core/cognition/__init__.py b/core/cognition/__init__.py
index e69de29bb..c4300b58a 100644
--- a/core/cognition/__init__.py
+++ b/core/cognition/__init__.py
@@ -0,0 +1,10 @@
+from .trace import Trace
+from .scene_expected import SceneExpected
+from .precondition import Precondition, PreconditionRecovery
+
+__all__ = [
+    "Trace",
+    "SceneExpected",
+    "Precondition",
+    "PreconditionRecovery",
+]
diff --git a/core/cognition/precondition.py b/core/cognition/precondition.py
new file mode 100644
index 000000000..b82af36a2
--- /dev/null
+++ b/core/cognition/precondition.py
@@ -0,0 +1,124 @@
+"""Précondition vérifiable + recovery — workpack B mandat/objectif.
+
+Cf. docs/coordination/inbox_codex/2026-05-25_0610_claude-to-codex_workpack-B-mandat-objectif-preconditions.md
+
+Précondition = l'état attendu vérifiable AVANT de tenter une action.
+Recovery = mini-séquence opt-in pour rattraper l'état si non atteint.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field, asdict
+from typing import Any, Dict, List, Optional, Tuple
+
+
+_VALID_KINDS = {"window_title", "scene_visible", "critic_question", "noop"}
+_VALID_FAIL_ACTIONS = {"pause", "abort", "continue_with_warning"}
+
+
+@dataclass(frozen=True)
+class Precondition:
+    """État attendu à vérifier AVANT l'action.
+
+    Attributs
+        kind                            : 'window_title' | 'scene_visible' | 'critic_question' | 'noop'
+        window_title_must_contain       : substrings dont au moins une doit être présente
+        window_title_must_not_contain   : substrings interdites (anti-intention)
+        critic_question                 : question fermée pour le Critic Ollama
+        verify_timeout_ms               : timeout de vérif
+    """
+
+    kind: str = "noop"
+    window_title_must_contain: Tuple[str, ...] = field(default_factory=tuple)
+    window_title_must_not_contain: Tuple[str, ...] = field(default_factory=tuple)
+    critic_question: str = ""
+    verify_timeout_ms: int = 2000
+
+    def __post_init__(self):
+        if self.kind not in _VALID_KINDS:
+            raise ValueError(f"Precondition.kind invalide: {self.kind!r} (attendu {_VALID_KINDS})")
+
+    def to_dict(self) -> Dict[str, Any]:
+        d = asdict(self)
+        d["window_title_must_contain"] = list(self.window_title_must_contain)
+        d["window_title_must_not_contain"] = list(self.window_title_must_not_contain)
+        return d
+
+    @classmethod
+    def from_dict(cls, data: Optional[Dict[str, Any]]) -> "Precondition":
+        if not data:
+            return cls()
+        return cls(
+            kind=str(data.get("kind", "noop") or "noop"),
+            window_title_must_contain=tuple(
+                str(x) for x in (data.get("window_title_must_contain") or [])
+            ),
+            window_title_must_not_contain=tuple(
+                str(x) for x in (data.get("window_title_must_not_contain") or [])
+            ),
+            critic_question=str(data.get("critic_question", "") or ""),
+            verify_timeout_ms=int(data.get("verify_timeout_ms", 2000) or 2000),
+        )
+
+    def is_noop(self) -> bool:
+        return self.kind == "noop"
+
+    def check_title(self, observed_title: str) -> bool:
+        """Vrai si le titre observé satisfait les contraintes (must/anti)."""
+        if self.kind != "window_title":
+            return True
+        if not observed_title:
+            return False
+        norm = observed_title.lower()
+        for anti in self.window_title_must_not_contain:
+            if anti and anti.lower() in norm:
+                return False
+        if not self.window_title_must_contain:
+            return True
+        return any(p and p.lower() in norm for p in self.window_title_must_contain)
+
+
+@dataclass(frozen=True)
+class PreconditionRecovery:
+    """Mini-séquence opt-in de rattrapage si la précondition n'est pas atteinte.
+
+    Attributs
+        max_attempts        : nombre max d'essais de recovery (par défaut 1)
+        on_recovery_fail    : 'pause' | 'abort' | 'continue_with_warning'
+        actions             : liste d'actions (même schéma que les actions du replay)
+    """
+
+    max_attempts: int = 1
+    on_recovery_fail: str = "pause"
+    actions: Tuple[Dict[str, Any], ...] = field(default_factory=tuple)
+
+    def __post_init__(self):
+        if self.on_recovery_fail not in _VALID_FAIL_ACTIONS:
+            raise ValueError(
+                f"PreconditionRecovery.on_recovery_fail invalide: {self.on_recovery_fail!r} "
+                f"(attendu {_VALID_FAIL_ACTIONS})"
+            )
+        if self.max_attempts < 0:
+            raise ValueError(f"max_attempts doit être >= 0, got {self.max_attempts}")
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "max_attempts": self.max_attempts,
+            "on_recovery_fail": self.on_recovery_fail,
+            "actions": [dict(a) for a in self.actions],
+        }
+
+    @classmethod
+    def from_dict(cls, data: Optional[Dict[str, Any]]) -> "PreconditionRecovery":
+        if not data:
+            return cls()
+        raw_actions = data.get("actions") or []
+        actions = tuple(dict(a) for a in raw_actions if isinstance(a, dict))
+        return cls(
+            max_attempts=int(data.get("max_attempts", 1) or 0),
+            on_recovery_fail=str(data.get("on_recovery_fail", "pause") or "pause"),
+            actions=actions,
+        )
+
+    def is_empty(self) -> bool:
+        return not self.actions
diff --git a/core/cognition/scene_expected.py b/core/cognition/scene_expected.py
new file mode 100644
index 000000000..e0e75e289
--- /dev/null
+++ b/core/cognition/scene_expected.py
@@ -0,0 +1,100 @@
+"""Scène d'intention attendue — workpack A attention scope multi-écrans.
+
+Cf. docs/coordination/inbox_codex/2026-05-25_0610_claude-to-codex_workpack-A-attention-scope-multi-ecrans.md
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field, asdict
+from typing import Any, Dict, List, Optional, Tuple
+
+
+@dataclass(frozen=True)
+class SceneExpected:
+    """Description du périmètre visuel attendu pour servir l'intention.
+
+    Construit au build serveur, transporté additif jusqu'au client, consommé
+    par une garde `_assert_scene_active()` avant tout geste — surtout les
+    raccourcis clavier qui partent sinon dans la fenêtre active globale.
+
+    Attributs
+        scene_id            : ID stable de la scène
+        app_name            : nom de l'application attendue (ex 'Notepad')
+        title_patterns      : patterns de titre acceptables (substrings)
+        title_anti          : patterns de titre interdits (anti-intention)
+        monitor_index       : index du moniteur (1-based mss). None = quelconque
+        monitor_geometry    : (left, top, width, height) en pixels. Optionnel.
+        window_rect_hint    : (left, top, right, bottom) zone attendue. Optionnel.
+        scene_role          : 'editor' | 'dialog' | 'menu' | 'browser_tab' | ...
+        required            : True si le geste DOIT être bloqué si scène absente
+        stability_ms        : durée min de stabilité avant le geste
+        accepted_transitions: scènes vers lesquelles transition est attendue
+    """
+
+    scene_id: str = ""
+    app_name: str = ""
+    title_patterns: Tuple[str, ...] = field(default_factory=tuple)
+    title_anti: Tuple[str, ...] = field(default_factory=tuple)
+    monitor_index: Optional[int] = None
+    monitor_geometry: Optional[Tuple[int, int, int, int]] = None
+    window_rect_hint: Optional[Tuple[int, int, int, int]] = None
+    scene_role: str = ""
+    required: bool = True
+    stability_ms: int = 0
+    accepted_transitions: Tuple[str, ...] = field(default_factory=tuple)
+
+    def to_dict(self) -> Dict[str, Any]:
+        d = asdict(self)
+        d["title_patterns"] = list(self.title_patterns)
+        d["title_anti"] = list(self.title_anti)
+        d["accepted_transitions"] = list(self.accepted_transitions)
+        if self.monitor_geometry is not None:
+            d["monitor_geometry"] = list(self.monitor_geometry)
+        if self.window_rect_hint is not None:
+            d["window_rect_hint"] = list(self.window_rect_hint)
+        return d
+
+    @classmethod
+    def from_dict(cls, data: Optional[Dict[str, Any]]) -> "SceneExpected":
+        if not data:
+            return cls()
+
+        def _tuple_of_4(v):
+            if v is None:
+                return None
+            try:
+                lst = list(v)
+                if len(lst) != 4:
+                    return None
+                return tuple(int(x) for x in lst)
+            except (TypeError, ValueError):
+                return None
+
+        return cls(
+            scene_id=str(data.get("scene_id", "") or ""),
+            app_name=str(data.get("app_name", "") or ""),
+            title_patterns=tuple(str(x) for x in (data.get("title_patterns") or [])),
+            title_anti=tuple(str(x) for x in (data.get("title_anti") or [])),
+            monitor_index=(int(data["monitor_index"]) if data.get("monitor_index") is not None else None),
+            monitor_geometry=_tuple_of_4(data.get("monitor_geometry")),
+            window_rect_hint=_tuple_of_4(data.get("window_rect_hint")),
+            scene_role=str(data.get("scene_role", "") or ""),
+            required=bool(data.get("required", True)),
+            stability_ms=int(data.get("stability_ms", 0) or 0),
+            accepted_transitions=tuple(str(x) for x in (data.get("accepted_transitions") or [])),
+        )
+
+    def matches_title(self, observed_title: str) -> bool:
+        """Vrai si le titre observé est cohérent avec la scène (patterns + anti)."""
+        if not observed_title:
+            return False
+        norm = observed_title.lower()
+        for anti in self.title_anti:
+            if anti and anti.lower() in norm:
+                return False
+        if not self.title_patterns:
+            return True
+        return any(p and p.lower() in norm for p in self.title_patterns)
+
+    def is_empty(self) -> bool:
+        return not (self.scene_id or self.app_name or self.title_patterns)
diff --git a/core/cognition/trace.py b/core/cognition/trace.py
new file mode 100644
index 000000000..287f69b7d
--- /dev/null
+++ b/core/cognition/trace.py
@@ -0,0 +1,59 @@
+"""Trace causale d'une action — modèle Mandat/Protocoles/Scènes v0.3.
+
+Cf. docs/architecture/MODELE_MANDAT_PROTOCOLS_LEA_2026-05-25_v0.3_ARBITRAGES_DOM.md
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field, asdict
+from typing import Any, Dict, Optional
+
+
+@dataclass(frozen=True)
+class Trace:
+    """Contrat unificateur transporté du build au runtime à la preuve.
+
+    Tous les champs sont optionnels (str vide / None) pour permettre une
+    introduction progressive sans casser les actions existantes qui n'en
+    portent pas. Fallback : comportement actuel si trace absente.
+
+    Attributs
+        mandate_id          : ID du mandat humain de niveau supérieur
+        intention_id        : ID du sous-but courant servant le mandat
+        scene_id            : ID de la scène d'intention pertinente
+        affordance_signature: signature stable de l'affordance ciblée
+        expected_retour     : description courte du retour attendu
+        level_of_delegation : N0..N4 (cf v0.3 arbitrage 3)
+    """
+
+    mandate_id: str = ""
+    intention_id: str = ""
+    scene_id: str = ""
+    affordance_signature: str = ""
+    expected_retour: str = ""
+    level_of_delegation: int = 0
+
+    def to_dict(self) -> Dict[str, Any]:
+        return asdict(self)
+
+    @classmethod
+    def from_dict(cls, data: Optional[Dict[str, Any]]) -> "Trace":
+        if not data:
+            return cls()
+        return cls(
+            mandate_id=str(data.get("mandate_id", "") or ""),
+            intention_id=str(data.get("intention_id", "") or ""),
+            scene_id=str(data.get("scene_id", "") or ""),
+            affordance_signature=str(data.get("affordance_signature", "") or ""),
+            expected_retour=str(data.get("expected_retour", "") or ""),
+            level_of_delegation=int(data.get("level_of_delegation", 0) or 0),
+        )
+
+    def is_empty(self) -> bool:
+        return not (
+            self.mandate_id
+            or self.intention_id
+            or self.scene_id
+            or self.affordance_signature
+            or self.expected_retour
+        )
diff --git a/tests/unit/test_cognition_dataclasses.py b/tests/unit/test_cognition_dataclasses.py
new file mode 100644
index 000000000..3281a0c5b
--- /dev/null
+++ b/tests/unit/test_cognition_dataclasses.py
@@ -0,0 +1,225 @@
+"""Tests offline des dataclasses cognition (Phase 2.1 + workpacks A/B).
+
+Pas de runtime, pas de réseau. Sérialisation JSON + invariants.
+"""
+
+from __future__ import annotations
+
+import json
+
+import pytest
+
+from core.cognition import (
+    Precondition,
+    PreconditionRecovery,
+    SceneExpected,
+    Trace,
+)
+
+
+# =============================================================================
+# Trace
+# =============================================================================
+
+
+def test_trace_empty_default():
+    t = Trace()
+    assert t.is_empty()
+    assert t.mandate_id == ""
+    assert t.intention_id == ""
+    assert t.level_of_delegation == 0
+
+
+def test_trace_roundtrip_json():
+    t = Trace(
+        mandate_id="m1",
+        intention_id="ouvrir_notepad",
+        scene_id="bloc_notes_vierge",
+        affordance_signature="btn:Enregistrer@SaveAs",
+        expected_retour="dialog Enregistrer sous apparaît",
+        level_of_delegation=2,
+    )
+    payload = json.dumps(t.to_dict())
+    loaded = Trace.from_dict(json.loads(payload))
+    assert loaded == t
+    assert not loaded.is_empty()
+
+
+def test_trace_from_dict_none_returns_empty():
+    assert Trace.from_dict(None) == Trace()
+
+
+def test_trace_from_dict_partial_tolerated():
+    loaded = Trace.from_dict({"mandate_id": "m1"})
+    assert loaded.mandate_id == "m1"
+    assert loaded.intention_id == ""
+    assert loaded.level_of_delegation == 0
+
+
+def test_trace_from_dict_level_must_be_int_parseable():
+    # Contrat documenté : from_dict tolère absent/None/0, pas une string non-int.
+    # Le caller serveur est responsable de produire un int valide.
+    with pytest.raises(ValueError):
+        Trace.from_dict({"level_of_delegation": "not_a_number"})
+
+
+# =============================================================================
+# SceneExpected
+# =============================================================================
+
+
+def test_scene_expected_empty_default():
+    s = SceneExpected()
+    assert s.is_empty()
+    assert s.monitor_index is None
+
+
+def test_scene_expected_roundtrip_json():
+    s = SceneExpected(
+        scene_id="bloc_notes_editor",
+        app_name="Notepad",
+        title_patterns=("Sans titre", "Untitled"),
+        title_anti=(".txt", ".md"),
+        monitor_index=1,
+        monitor_geometry=(0, 0, 1920, 1080),
+        window_rect_hint=(100, 100, 1000, 800),
+        scene_role="editor",
+        required=True,
+        stability_ms=200,
+        accepted_transitions=("save_as_dialog", "confirm_save"),
+    )
+    payload = json.dumps(s.to_dict())
+    loaded = SceneExpected.from_dict(json.loads(payload))
+    assert loaded == s
+
+
+def test_scene_expected_matches_title_anti_blocks():
+    s = SceneExpected(
+        app_name="Notepad",
+        title_patterns=("Sans titre",),
+        title_anti=(".txt",),
+    )
+    assert s.matches_title("Sans titre – Bloc-notes") is True
+    assert s.matches_title("monfichier.txt – Bloc-notes") is False
+    assert s.matches_title("Sans titre.txt") is False  # anti l'emporte
+
+
+def test_scene_expected_matches_title_no_patterns_accepts_all_except_anti():
+    s = SceneExpected(app_name="Notepad", title_anti=("Chrome",))
+    assert s.matches_title("Bloc-notes") is True
+    assert s.matches_title("Google Chrome") is False
+
+
+def test_scene_expected_matches_title_empty_observed_false():
+    s = SceneExpected(title_patterns=("Notepad",))
+    assert s.matches_title("") is False
+
+
+def test_scene_expected_from_dict_bad_geometry_falls_back_none():
+    s = SceneExpected.from_dict({"monitor_geometry": [1, 2, 3]})  # pas 4 valeurs
+    assert s.monitor_geometry is None
+
+
+# =============================================================================
+# Precondition
+# =============================================================================
+
+
+def test_precondition_noop_default():
+    p = Precondition()
+    assert p.is_noop()
+    assert p.kind == "noop"
+
+
+def test_precondition_invalid_kind_raises():
+    with pytest.raises(ValueError):
+        Precondition(kind="unknown_kind")
+
+
+def test_precondition_window_title_check_must_contain():
+    p = Precondition(
+        kind="window_title",
+        window_title_must_contain=("Sans titre", "Untitled"),
+    )
+    assert p.check_title("Sans titre – Bloc-notes") is True
+    assert p.check_title("Untitled - Notepad") is True
+    assert p.check_title("monfichier.txt – Bloc-notes") is False
+
+
+def test_precondition_window_title_anti_blocks_even_if_must_present():
+    p = Precondition(
+        kind="window_title",
+        window_title_must_contain=("Bloc-notes",),
+        window_title_must_not_contain=(".txt",),
+    )
+    assert p.check_title("Sans titre – Bloc-notes") is True
+    assert p.check_title("rapport.txt – Bloc-notes") is False
+
+
+def test_precondition_check_title_noop_returns_true():
+    """Précondition noop ne bloque jamais — comportement par défaut."""
+    p = Precondition(kind="noop")
+    assert p.check_title("n'importe quoi") is True
+
+
+def test_precondition_roundtrip_json():
+    p = Precondition(
+        kind="window_title",
+        window_title_must_contain=("Sans titre",),
+        window_title_must_not_contain=(".txt",),
+        critic_question="Le document est-il vide et non nommé ?",
+        verify_timeout_ms=3000,
+    )
+    payload = json.dumps(p.to_dict())
+    loaded = Precondition.from_dict(json.loads(payload))
+    assert loaded == p
+
+
+# =============================================================================
+# PreconditionRecovery
+# =============================================================================
+
+
+def test_recovery_default_empty():
+    r = PreconditionRecovery()
+    assert r.is_empty()
+    assert r.max_attempts == 1
+    assert r.on_recovery_fail == "pause"
+
+
+def test_recovery_invalid_fail_action_raises():
+    with pytest.raises(ValueError):
+        PreconditionRecovery(on_recovery_fail="continue_aveuglement")
+
+
+def test_recovery_negative_attempts_raises():
+    with pytest.raises(ValueError):
+        PreconditionRecovery(max_attempts=-1)
+
+
+def test_recovery_with_actions_serializable():
+    r = PreconditionRecovery(
+        max_attempts=1,
+        on_recovery_fail="pause",
+        actions=(
+            {"type": "key_combo", "keys": ["ctrl", "n"]},
+            {"type": "wait", "duration_ms": 500},
+        ),
+    )
+    payload = json.dumps(r.to_dict())
+    loaded = PreconditionRecovery.from_dict(json.loads(payload))
+    assert loaded == r
+    assert not loaded.is_empty()
+
+
+def test_recovery_from_dict_filters_non_dict_actions():
+    r = PreconditionRecovery.from_dict({
+        "actions": [
+            {"type": "key_combo"},
+            "ignored_string",
+            None,
+            42,
+            {"type": "wait"},
+        ],
+    })
+    assert len(r.actions) == 2