diff --git a/src/autoskillit/hook_registry.py b/src/autoskillit/hook_registry.py
index 2f9c0c813..6d56419e8 100644
--- a/src/autoskillit/hook_registry.py
+++ b/src/autoskillit/hook_registry.py
@@ -31,6 +31,7 @@ class HookDef:
         "works-as-is"
     )
     mechanism: Literal["deny", "additionalContext", "output-rewrite"] = "deny"
+    enforcement_strength: dict[str, str] = field(default_factory=dict)
 
     def __post_init__(self) -> None:
         if self.event_type != "SessionStart" and not self.matcher:
@@ -96,17 +97,20 @@ def __post_init__(self) -> None:
             "guards/pipeline_step_guard.py",
         ],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher="mcp__.*autoskillit.*__remove_clone",
         scripts=["guards/remove_clone_guard.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"mcp__.*autoskillit.*__open_kitchen.*",
         scripts=["guards/open_kitchen_guard.py"],
         timeout_seconds=5,
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher="AskUserQuestion",
@@ -115,21 +119,25 @@ def __post_init__(self) -> None:
         session_scope="headless_only",
         codex_status="not-applicable",
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "not-applicable"},
     ),
     HookDef(
         matcher=r"mcp__.*autoskillit.*__merge_worktree",
         scripts=["guards/branch_protection_guard.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"mcp__.*autoskillit.*__push_to_remote",
         scripts=["guards/branch_protection_guard.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__run_cmd",
         scripts=["guards/unsafe_install_guard.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__run_cmd",
@@ -149,23 +157,27 @@ def __post_init__(self) -> None:
         # stdlib-only boundary on hook scripts prevents a shared import.
         exempt_session_types=frozenset({"orchestrator"}),
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__run_cmd",
         scripts=["guards/compose_pr_body_guard.py"],
         session_scope="headless_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__run_cmd",
         scripts=["guards/planner_gh_discovery_guard.py"],
         session_scope="headless_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__run_cmd",
         scripts=["guards/artifact_download_guard.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__run_cmd",
@@ -175,6 +187,7 @@ def __post_init__(self) -> None:
         # stdlib-only boundary on hook scripts prevents a shared import.
         exempt_session_types=frozenset({"orchestrator"}),
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__run_cmd",
@@ -184,35 +197,41 @@ def __post_init__(self) -> None:
         # stdlib-only boundary on hook scripts prevents a shared import.
         exempt_skills=frozenset({"implement-experiment"}),
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Write|Edit",
         scripts=["guards/generated_file_write_guard.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Write|Edit|Bash|mcp__.*autoskillit.*__run_cmd",
         scripts=["guards/write_guard.py"],
         session_scope="headless_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Write|Edit",
         scripts=["guards/planner_result_naming_guard.py"],
         session_scope="headless_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Write|Edit",
         scripts=["guards/recipe_write_advisor.py"],
         session_scope="interactive_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Grep",
         scripts=["guards/grep_pattern_lint_guard.py"],
         codex_status="not-applicable",
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "not-applicable"},
     ),
     HookDef(
         matcher=r"Bash|Write|Edit|Read|Glob|Grep",
@@ -221,24 +240,28 @@ def __post_init__(self) -> None:
         session_scope="interactive_only",
         codex_status="degraded",
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "degraded"},
     ),
     HookDef(
         matcher=r"mcp__.*autoskillit.*__(run_skill|run_cmd|run_python).*",
         scripts=["guards/skill_orchestration_guard.py"],
         session_scope="headless_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|mcp__.*autoskillit.*__(run_cmd|run_python)",
         scripts=["guards/recipe_read_guard.py"],
         session_scope="headless_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"Bash|Agent",
         scripts=["guards/background_exec_guard.py"],
         session_scope="headless_only",
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"(mcp__.*autoskillit.*__)?dispatch_food_truck",
@@ -249,12 +272,14 @@ def __post_init__(self) -> None:
             "guards/fleet_claim_guard.py",
         ],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         event_type="PostToolUse",
         matcher="mcp__.*autoskillit.*",
         scripts=["formatters/pretty_output_hook.py"],
         mechanism="output-rewrite",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         event_type="PostToolUse",
@@ -266,18 +291,21 @@ def __post_init__(self) -> None:
             "recipe_confirmed_post_hook.py",
         ],
         mechanism="output-rewrite",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         event_type="PostToolUse",
         matcher=r"mcp__.*autoskillit.*__(run_skill|run_python).*",
         scripts=["review_gate_post_hook.py"],
         mechanism="output-rewrite",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         event_type="PostToolUse",
         matcher=r"(mcp__.*autoskillit.*__)?dispatch_food_truck",
         scripts=["resume_gate_post_hook.py"],
         mechanism="output-rewrite",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         event_type="PostToolUse",
@@ -286,6 +314,7 @@ def __post_init__(self) -> None:
         session_scope="headless_only",
         codex_status="degraded",
         mechanism="output-rewrite",
+        enforcement_strength={"claude_code": "hard", "codex": "degraded"},
     ),
     HookDef(
         event_type="PostToolUse",
@@ -293,6 +322,7 @@ def __post_init__(self) -> None:
         scripts=["skill_load_post_hook.py"],
         codex_status="not-applicable",
         mechanism="additionalContext",
+        enforcement_strength={"claude_code": "hard", "codex": "not-applicable"},
     ),
     HookDef(
         matcher=r"Read|Write|Edit|Bash|Grep|Glob",
@@ -300,22 +330,26 @@ def __post_init__(self) -> None:
         session_scope="headless_only",
         codex_status="works-as-is",
         mechanism="deny",
+        enforcement_strength={"claude_code": "hard", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"mcp__.*autoskillit.*__(wait_for_ci|enqueue_pr)",
         scripts=["guards/review_loop_gate.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         matcher=r"(mcp__.*autoskillit.*__)?reset_dispatch",
         scripts=["guards/reset_resume_gate.py"],
         mechanism="deny",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
     HookDef(
         event_type="SessionStart",
         scripts=["session_start_hook.py"],
         session_scope="interactive_only",
         mechanism="additionalContext",
+        enforcement_strength={"claude_code": "soft", "codex": "works-as-is"},
     ),
 ]
 
@@ -418,6 +452,7 @@ def _canonical_registry_payload(
         [
             {
                 "codex_status": h.codex_status,
+                "enforcement_strength": dict(sorted(h.enforcement_strength.items())),
                 "event_type": h.event_type,
                 "exempt_session_types": sorted(h.exempt_session_types),
                 "exempt_skills": sorted(h.exempt_skills),
@@ -432,7 +467,7 @@ def _canonical_registry_payload(
         key=lambda row: (row["event_type"], row["matcher"], tuple(row["scripts"])),  # type: ignore[arg-type]
     )
     return json.dumps(
-        {"format_version": 2, "registry": registry_rows, "retired": sorted(retired)},
+        {"format_version": 3, "registry": registry_rows, "retired": sorted(retired)},
         sort_keys=True,
         separators=(",", ":"),
     )
diff --git a/src/autoskillit/hooks/registry.sha256 b/src/autoskillit/hooks/registry.sha256
index e6d2b113b..628f7f8dc 100644
--- a/src/autoskillit/hooks/registry.sha256
+++ b/src/autoskillit/hooks/registry.sha256
@@ -1 +1 @@
-e2026897c0e2c46ff1b6beb448cade141294f1c7b296dad2b4cf46e61d8c646e
+cf12c32c7990708aedb676d6fcf239fb2b7c1a90d61444d5cb367daf0cfa7795
diff --git a/tests/execution/backends/fixtures/codex_ndjson/hook_event_format_snapshot.json b/tests/execution/backends/fixtures/codex_ndjson/hook_event_format_snapshot.json
index b91e3dd4c..21a611e27 100644
--- a/tests/execution/backends/fixtures/codex_ndjson/hook_event_format_snapshot.json
+++ b/tests/execution/backends/fixtures/codex_ndjson/hook_event_format_snapshot.json
@@ -1,6 +1,5 @@
 {
-  "_registry_hash": "e2026897c0e2c46ff1b6beb448cade141294f1c7b296dad2b4cf46e61d8c646e",
-  "_staleness_note": "Regenerate in the same commit as P5-A6 (B4-hookdef-extension) when mechanism/enforcement_strength fields are added to HookDef.",
+  "_registry_hash": "cf12c32c7990708aedb676d6fcf239fb2b7c1a90d61444d5cb367daf0cfa7795",
   "hooks": {
     "PostToolUse": [
       {
diff --git a/tests/hooks/test_hook_registry_codex_status.py b/tests/hooks/test_hook_registry_codex_status.py
index e04730a8e..4c2e23e8c 100644
--- a/tests/hooks/test_hook_registry_codex_status.py
+++ b/tests/hooks/test_hook_registry_codex_status.py
@@ -7,7 +7,13 @@
 import pytest
 
 from autoskillit.execution.backends._codex_hooks import generate_codex_hooks_config
-from autoskillit.hook_registry import HookDef
+from autoskillit.hook_registry import (
+    HOOK_REGISTRY_HASH,
+    RETIRED_SCRIPT_BASENAMES,
+    HookDef,
+    _canonical_registry_payload,
+    compute_registry_hash,
+)
 from autoskillit.hooks import HOOK_REGISTRY
 
 pytestmark = [pytest.mark.layer("hooks"), pytest.mark.medium]
@@ -81,3 +87,67 @@ def test_posttooluse_pretty_output_is_output_rewrite(self):
                     f"Hook {hook_def.scripts} has mechanism={hook_def.mechanism!r}, "
                     "expected 'output-rewrite' for pretty_output_hook"
                 )
+
+    def test_hookdef_has_enforcement_strength_field(self):
+        field_names = {f.name for f in dataclasses.fields(HookDef)}
+        assert "enforcement_strength" in field_names
+
+    def test_enforcement_strength_default_is_empty_dict(self):
+        hd = HookDef(matcher="test", scripts=["s.py"])
+        assert hd.enforcement_strength == {}
+
+    def test_all_registry_entries_have_enforcement_strength_keys(self):
+        for hd in HOOK_REGISTRY:
+            assert "claude_code" in hd.enforcement_strength, (
+                f"Hook {hd.scripts} missing 'claude_code' key"
+            )
+            assert "codex" in hd.enforcement_strength, f"Hook {hd.scripts} missing 'codex' key"
+
+    def test_enforcement_strength_claude_code_values_are_valid(self):
+        for hd in HOOK_REGISTRY:
+            assert hd.enforcement_strength["claude_code"] in ("hard", "soft"), (
+                f"Hook {hd.scripts} has invalid claude_code: "
+                f"{hd.enforcement_strength['claude_code']!r}"
+            )
+
+    def test_enforcement_strength_codex_matches_codex_status(self):
+        for hd in HOOK_REGISTRY:
+            assert hd.enforcement_strength["codex"] == hd.codex_status, (
+                f"Hook {hd.scripts}: enforcement_strength codex="
+                f"{hd.enforcement_strength['codex']!r} != "
+                f"codex_status={hd.codex_status!r}"
+            )
+
+    def test_compute_registry_hash_changes_on_enforcement_strength(self):
+        original = HOOK_REGISTRY[0]
+        mutated_entry = dataclasses.replace(
+            original,
+            enforcement_strength={"claude_code": "hard", "codex": "test-sentinel"},
+        )
+        mutated_registry = [mutated_entry, *HOOK_REGISTRY[1:]]
+        new_hash = compute_registry_hash(mutated_registry, RETIRED_SCRIPT_BASENAMES)
+        assert new_hash != HOOK_REGISTRY_HASH
+
+    def test_format_version_is_3(self):
+        import json
+
+        payload = json.loads(_canonical_registry_payload(HOOK_REGISTRY, RETIRED_SCRIPT_BASENAMES))
+        assert payload["format_version"] == 3
+
+    def test_enforcement_strength_round_trip(self):
+        es = {"claude_code": "hard", "codex": "works-as-is"}
+        hd = HookDef(matcher="test", scripts=["s.py"], enforcement_strength=es)
+        assert hd.enforcement_strength == es
+        assert hd.enforcement_strength["claude_code"] == "hard"
+        assert hd.enforcement_strength["codex"] == "works-as-is"
+
+    def test_canonical_registry_payload_includes_enforcement_strength(self):
+        import json
+
+        payload_str = _canonical_registry_payload(HOOK_REGISTRY, RETIRED_SCRIPT_BASENAMES)
+        payload = json.loads(payload_str)
+        for row in payload["registry"]:
+            assert "enforcement_strength" in row, (
+                f"Registry row for matcher={row.get('matcher')!r} is missing"
+                " 'enforcement_strength'. Add it to _canonical_registry_payload."
+            )