diff --git a/install.sh b/install.sh
index df239f8e..d2c16ec7 100755
--- a/install.sh
+++ b/install.sh
@@ -230,6 +230,7 @@ mkdir -p "$HOME/.claude/hooks"
 link_item "_markers" "$REPO_DIR/engine/hooks/_markers" "$HOME/.claude/hooks/_markers"
 link_item "_runner" "$REPO_DIR/engine/hooks/_runner" "$HOME/.claude/hooks/_runner"
 link_item "_flags" "$REPO_DIR/engine/hooks/_flags" "$HOME/.claude/hooks/_flags"
+link_item "_sdk" "$REPO_DIR/engine/hooks/_sdk" "$HOME/.claude/hooks/_sdk"
 link_item "diu-stop" "$REPO_DIR/engine/hooks/diu-stop" "$HOME/.claude/hooks/diu-stop"
 link_item "bug-complaint-leak" "$REPO_DIR/engine/hooks/bug-complaint-leak" "$HOME/.claude/hooks/bug-complaint-leak"
 link_item "demo-freeze" "$REPO_DIR/engine/hooks/demo-freeze" "$HOME/.claude/hooks/demo-freeze"
@@ -285,6 +286,8 @@ echo "--- cursor hooks dir (\$HOME/.cursor/hooks) ---"
 mkdir -p "$HOME/.cursor/hooks"
 link_item "_runner" "$REPO_DIR/engine/hooks/_runner" "$HOME/.cursor/hooks/_runner"
 link_item "_flags" "$REPO_DIR/engine/hooks/_flags" "$HOME/.cursor/hooks/_flags"
+link_item "_sdk" "$REPO_DIR/engine/hooks/_sdk" "$HOME/.cursor/hooks/_sdk"
+link_item "_markers" "$REPO_DIR/engine/hooks/_markers" "$HOME/.cursor/hooks/_markers"
 link_item "bug-complaint-leak" "$REPO_DIR/engine/hooks/bug-complaint-leak" "$HOME/.cursor/hooks/bug-complaint-leak"
 link_item "reflect-on-thrash" "$REPO_DIR/engine/hooks/reflect-on-thrash" "$HOME/.cursor/hooks/reflect-on-thrash"
 link_item "scope-lock" "$REPO_DIR/engine/hooks/scope-lock" "$HOME/.cursor/hooks/scope-lock"
@@ -304,6 +307,8 @@ echo "--- codex hooks (\$HOME/.codex/hooks) ---"
 mkdir -p "$HOME/.codex/hooks"
 link_item "_runner" "$REPO_DIR/engine/hooks/_runner" "$HOME/.codex/hooks/_runner"
 link_item "_flags" "$REPO_DIR/engine/hooks/_flags" "$HOME/.codex/hooks/_flags"
+link_item "_sdk" "$REPO_DIR/engine/hooks/_sdk" "$HOME/.codex/hooks/_sdk"
+link_item "_markers" "$REPO_DIR/engine/hooks/_markers" "$HOME/.codex/hooks/_markers"
 link_item "diu-stop" "$REPO_DIR/engine/hooks/diu-stop" "$HOME/.codex/hooks/diu-stop"
 link_item "scope-lock" "$REPO_DIR/engine/hooks/scope-lock" "$HOME/.codex/hooks/scope-lock"
 link_item "auto-pr" "$REPO_DIR/engine/hooks/auto-pr" "$HOME/.codex/hooks/auto-pr"
diff --git a/tests/test_install.py b/tests/test_install.py
index bbb974db..ba9368c8 100644
--- a/tests/test_install.py
+++ b/tests/test_install.py
@@ -17,6 +17,7 @@
 $REPO_DIR/engine/hooks -- correct, since that's the real content under test -- and
 nothing anywhere writes back into $REPO_DIR.
 """
+import glob
 import json
 import os
 import re
@@ -1473,3 +1474,45 @@ def test_each_installer_survives_dangling_link(self):
                 self.assertFalse(os.path.islink(hooks_path))
                 with open(hooks_path) as handle:
                     json.load(handle)
+
+
+class TestInstalledHookScriptsImport(unittest.TestCase):
+    SKIP_PREFIXES = ("install_", "test_")
+    SKIP_NAMES = ("detect.py", "state.py")
+
+    def test_every_installed_hook_script_finds_its_shared_modules(self):
+        with tempfile.TemporaryDirectory() as fake_home, tempfile.TemporaryDirectory() as cwd:
+            proc = run_install(fake_home)
+            self.assertEqual(proc.returncode, 0, proc.stderr)
+            failures = []
+            still_running = []
+            checked = 0
+            for harness in (".claude", ".cursor", ".codex"):
+                for path in sorted(glob.glob(os.path.join(fake_home, harness, "hooks", "*", "*.py"))):
+                    hook = os.path.basename(os.path.dirname(path))
+                    name = os.path.basename(path)
+                    if hook.startswith("_") or name.startswith(self.SKIP_PREFIXES) or name in self.SKIP_NAMES:
+                        continue
+                    checked += 1
+                    try:
+                        result = subprocess.run(
+                            [sys.executable, path],
+                            input="{}",
+                            env={**os.environ, "HOME": fake_home},
+                            cwd=cwd,
+                            capture_output=True,
+                            text=True,
+                            timeout=5,
+                        )
+                    except subprocess.TimeoutExpired as exc:
+                        stderr = exc.stderr.decode() if isinstance(exc.stderr, bytes) else (exc.stderr or "")
+                        if "ModuleNotFoundError" in stderr or "ImportError" in stderr:
+                            failures.append(f"{harness}/hooks/{hook}/{name}: import error, then hung")
+                        else:
+                            still_running.append(f"{harness}/hooks/{hook}/{name}")
+                        continue
+                    if "ModuleNotFoundError" in result.stderr or "ImportError" in result.stderr:
+                        failures.append(f"{harness}/hooks/{hook}/{name}: {result.stderr.strip().splitlines()[-1]}")
+            self.assertGreater(checked, 0)
+            self.assertLess(len(still_running), checked, still_running)
+            self.assertEqual(failures, [], "\n".join(failures))