fix(hook): keep composite hooks backward compatible

Avoid AttributeError regressions when hooks define their own __init__ or when a CompositeHook wraps another composite.

Made-with: Cursor

nanobot/agent/hook.py

@@ -65,6 +65,7 @@ class CompositeHook(AgentHook):
     __slots__ = ("_hooks",)
 
     def __init__(self, hooks: list[AgentHook]) -> None:
+        super().__init__()
         self._hooks = list(hooks)
 
     def wants_streaming(self) -> bool:
@@ -72,7 +73,7 @@ class CompositeHook(AgentHook):
 
     async def _for_each_hook_safe(self, method_name: str, *args: Any, **kwargs: Any) -> None:
         for h in self._hooks:
-            if h._reraise:
+            if getattr(h, "_reraise", False):
                 await getattr(h, method_name)(*args, **kwargs)
                 continue
 

nanobot/agent/subagent.py

@@ -27,6 +27,7 @@ class _SubagentHook(AgentHook):
     """Logging-only hook for subagent execution."""
 
     def __init__(self, task_id: str) -> None:
+        super().__init__()
         self._task_id = task_id
 
     async def before_execute_tools(self, context: AgentHookContext) -> None:

tests/agent/test_hook_composite.py

@@ -232,6 +232,35 @@ async def test_composite_empty_hooks_no_ops():
     assert hook.finalize_content(ctx, "test") == "test"
 
 
+@pytest.mark.asyncio
+async def test_composite_supports_legacy_hook_init_without_super():
+    calls: list[str] = []
+
+    class LegacyHook(AgentHook):
+        def __init__(self, label: str) -> None:
+            self.label = label
+
+        async def before_iteration(self, context: AgentHookContext) -> None:
+            calls.append(self.label)
+
+    hook = CompositeHook([LegacyHook("legacy")])
+    await hook.before_iteration(_ctx())
+    assert calls == ["legacy"]
+
+
+@pytest.mark.asyncio
+async def test_composite_can_wrap_another_composite():
+    calls: list[str] = []
+
+    class Inner(AgentHook):
+        async def before_iteration(self, context: AgentHookContext) -> None:
+            calls.append("inner")
+
+    hook = CompositeHook([CompositeHook([Inner()])])
+    await hook.before_iteration(_ctx())
+    assert calls == ["inner"]
+
+
 # ---------------------------------------------------------------------------
 # Integration: AgentLoop with extra hooks
 # ---------------------------------------------------------------------------