diff --git a/README.md b/README.md
index 3346abe..ea800cb 100644
--- a/README.md
+++ b/README.md
@@ -73,6 +73,8 @@ elydora install \
   --kid agent-456-key-v1
 ```
 
+Codex performs a one-time trust review for user hooks. Run `/hooks` in Codex after installation and trust the Elydora `PreToolUse` and `PostToolUse` definitions.
+
 Kiro CLI installation covers both runtime contracts. Kiro CLI v2 uses the generated custom agent through `kiro-cli --agent elydora-audit`. Kiro CLI v3 loads the global standalone hooks when started with `kiro-cli --v3`.
 
 ### Commands
@@ -89,6 +91,7 @@ Kiro CLI installation covers both runtime contracts. Kiro CLI v2 uses the genera
 | Agent | Key |
 |-------|-----|
 | Claude Code | `claudecode` |
+| OpenAI Codex | `codex` |
 | Copilot CLI | `copilot` |
 | Cursor | `cursor` |
 | Gemini CLI | `gemini` |
diff --git a/elydora/cli.py b/elydora/cli.py
index 721bb99..899c12c 100644
--- a/elydora/cli.py
+++ b/elydora/cli.py
@@ -19,6 +19,7 @@ from .plugins.base import AgentPlugin, InstallConfig
 from .plugins.registry import SUPPORTED_AGENTS, get_agent_names
 from .plugins.hook_template import generate_guard_script
 from .plugins.claudecode import ClaudeCodePlugin
+from .plugins.codex import CodexPlugin
 from .plugins.copilot import CopilotPlugin
 from .plugins.cursor import CursorPlugin
 from .plugins.gemini import GeminiPlugin
@@ -30,6 +31,7 @@ from .plugins.opencode import OpenCodePlugin
 
 PLUGIN_MAP: Dict[str, Type[AgentPlugin]] = {
     "claudecode": ClaudeCodePlugin,
+    "codex": CodexPlugin,
     "copilot": CopilotPlugin,
     "cursor": CursorPlugin,
     "gemini": GeminiPlugin,
diff --git a/elydora/plugins/codex.py b/elydora/plugins/codex.py
new file mode 100644
index 0000000..0d1d1b9
--- /dev/null
+++ b/elydora/plugins/codex.py
@@ -0,0 +1,419 @@
+"""OpenAI Codex lifecycle-hook integration."""
+
+from __future__ import annotations
+
+import json
+import os
+import shlex
+import stat
+# subprocess provides argument quoting only; this module starts no process.
+import subprocess  # nosec B404
+import sys
+import tempfile
+from typing import Any, Dict, List, Optional
+
+from .base import AgentPlugin, InstallConfig, PluginStatus
+from .hook_template import generate_hook_script
+
+
+AGENT_KEY = "codex"
+OWNED_DESCRIPTION = "Elydora audit and freeze enforcement"
+GUARD_STATUS = "Checking Elydora agent state"
+AUDIT_STATUS = "Recording Elydora tool use"
+GUARD_SCRIPT = "guard.py"
+AUDIT_SCRIPT = "hook.py"
+ELYDORA_DIR = os.path.join(os.path.expanduser("~"), ".elydora")
+CONFIG_PATH = os.path.join(os.path.expanduser("~"), ".codex", "hooks.json")
+
+JsonObject = Dict[str, Any]
+
+
+def _read_json(path: str, label: str) -> Optional[JsonObject]:
+    try:
+        with open(path, "r", encoding="utf-8") as file:
+            raw = file.read()
+    except FileNotFoundError:
+        return None
+    except OSError as error:
+        raise OSError(f"Read {label} at {path}: {error}") from error
+
+    try:
+        value = json.loads(raw)
+    except json.JSONDecodeError as error:
+        raise ValueError(f"Failed to parse {label} at {path}: {error}") from error
+    if not isinstance(value, dict):
+        raise ValueError(f"{label} at {path} must contain a JSON object")
+    return value
+
+
+def _cleanup_failed_write(path: str, label: str, cause: Exception) -> None:
+    try:
+        os.remove(path)
+    except FileNotFoundError:
+        return
+    except OSError as cleanup_error:
+        raise OSError(
+            f"Write {label} failed: {cause}; cleanup of {path} failed: {cleanup_error}"
+        ) from cause
+
+
+def _write_text_atomic(path: str, content: str, mode: int, label: str) -> None:
+    directory = os.path.dirname(path)
+    try:
+        os.makedirs(directory, mode=0o700, exist_ok=True)
+    except OSError as error:
+        raise OSError(f"Create directory for {label} at {directory}: {error}") from error
+
+    descriptor = -1
+    temporary_path = ""
+    try:
+        descriptor, temporary_path = tempfile.mkstemp(
+            prefix=f".{os.path.basename(path)}.",
+            suffix=".tmp",
+            dir=directory,
+            text=True,
+        )
+        with os.fdopen(descriptor, "w", encoding="utf-8", newline="\n") as file:
+            descriptor = -1
+            file.write(content)
+            file.flush()
+            os.fsync(file.fileno())
+        os.chmod(temporary_path, mode)
+        os.replace(temporary_path, path)
+    except Exception as error:
+        if descriptor >= 0:
+            try:
+                os.close(descriptor)
+            except OSError as close_error:
+                _cleanup_failed_write(temporary_path, label, close_error)
+                raise OSError(
+                    f"Write {label} at {path} failed: {error}; "
+                    f"close failed: {close_error}"
+                ) from error
+        _cleanup_failed_write(temporary_path, label, error)
+        raise OSError(f"Write {label} at {path}: {error}") from error
+
+
+def _write_json_atomic(path: str, value: JsonObject, mode: int, label: str) -> None:
+    encoded = json.dumps(value, indent=2) + "\n"
+    _write_text_atomic(path, encoded, mode, label)
+
+
+def _remove_file(path: str, label: str) -> None:
+    try:
+        os.remove(path)
+    except FileNotFoundError:
+        return
+    except OSError as error:
+        raise OSError(f"Remove {label} at {path}: {error}") from error
+
+
+def _regular_file_exists(path: str, label: str) -> bool:
+    try:
+        metadata = os.stat(path)
+    except FileNotFoundError:
+        return False
+    except OSError as error:
+        raise OSError(f"Read {label} at {path}: {error}") from error
+    return stat.S_ISREG(metadata.st_mode)
+
+
+def _require_runtime(path: str, label: str) -> None:
+    if not path:
+        raise ValueError(f"{label} path is required")
+    if not _regular_file_exists(path, label):
+        raise FileNotFoundError(f"{label} is missing: {path}")
+
+
+def _build_handler(script_path: str, status_message: str) -> JsonObject:
+    return {
+        "type": "command",
+        "command": f"{shlex.quote(sys.executable)} {shlex.quote(script_path)}",
+        "commandWindows": subprocess.list2cmdline([sys.executable, script_path]),
+        "timeout": 10,
+        "statusMessage": status_message,
+    }
+
+
+def _hooks_object(settings: JsonObject) -> JsonObject:
+    if "hooks" not in settings:
+        return {}
+    hooks = settings["hooks"]
+    if not isinstance(hooks, dict):
+        raise ValueError('Codex hooks config field "hooks" must be an object')
+    return dict(hooks)
+
+
+def _event_groups(hooks: JsonObject, event: str) -> List[JsonObject]:
+    if event not in hooks:
+        return []
+    groups = hooks[event]
+    if not isinstance(groups, list) or not all(
+        isinstance(group, dict) for group in groups
+    ):
+        raise ValueError(
+            f'Codex hooks config field "hooks.{event}" must be an array of objects'
+        )
+    return groups
+
+
+def _is_managed_command(command: Any, script_name: str, agent_id: str = "") -> bool:
+    if not isinstance(command, str):
+        return False
+    normalized = os.path.normcase(command)
+    if ".elydora" not in normalized or script_name.lower() not in normalized.lower():
+        return False
+    if not agent_id:
+        return True
+    expected_path = os.path.normcase(
+        os.path.join(ELYDORA_DIR, agent_id, script_name)
+    )
+    return expected_path in normalized
+
+
+def _is_elydora_handler(handler: JsonObject, agent_id: str = "") -> bool:
+    status_message = handler.get("statusMessage")
+    if status_message == GUARD_STATUS:
+        script_name = GUARD_SCRIPT
+    elif status_message == AUDIT_STATUS:
+        script_name = AUDIT_SCRIPT
+    else:
+        return False
+    return any(
+        _is_managed_command(handler.get(key), script_name, agent_id)
+        for key in ("command", "commandWindows")
+    )
+
+
+def _without_elydora(
+    groups: List[JsonObject],
+    agent_id: str = "",
+) -> List[JsonObject]:
+    filtered_groups: List[JsonObject] = []
+    for group in groups:
+        handlers = group.get("hooks")
+        if not isinstance(handlers, list) or not all(
+            isinstance(handler, dict) for handler in handlers
+        ):
+            raise ValueError("Codex hook matcher group must contain a hooks array")
+        filtered = [
+            handler
+            for handler in handlers
+            if not _is_elydora_handler(handler, agent_id)
+        ]
+        if filtered:
+            filtered_groups.append({**group, "hooks": filtered})
+    return filtered_groups
+
+
+def _find_handler(
+    groups: List[JsonObject],
+    status_message: str,
+) -> Optional[JsonObject]:
+    for group in groups:
+        handlers = group.get("hooks")
+        if not isinstance(handlers, list) or not all(
+            isinstance(handler, dict) for handler in handlers
+        ):
+            raise ValueError("Codex hook matcher group must contain a hooks array")
+        for handler in handlers:
+            if (
+                handler.get("statusMessage") == status_message
+                and _is_elydora_handler(handler)
+            ):
+                return handler
+    return None
+
+
+def _command_references(handler: JsonObject, script_path: str) -> bool:
+    return any(
+        isinstance(handler.get(key), str) and script_path in handler[key]
+        for key in ("command", "commandWindows")
+    )
+
+
+def _is_owned_settings(settings: JsonObject, hooks: JsonObject) -> bool:
+    settings_keys = {"description", "hooks"}
+    hook_keys = {"PreToolUse", "PostToolUse"}
+    return (
+        all(key in settings_keys for key in settings)
+        and settings.get("description") == OWNED_DESCRIPTION
+        and all(key in hook_keys for key in hooks)
+        and all(isinstance(value, list) and not value for value in hooks.values())
+    )
+
+
+def _runtime_scripts_exist(guard: JsonObject, audit: JsonObject) -> bool:
+    try:
+        with os.scandir(ELYDORA_DIR) as iterator:
+            entries = sorted(iterator, key=lambda entry: entry.name)
+    except FileNotFoundError:
+        return False
+    except OSError as error:
+        raise OSError(
+            f"Read Elydora runtime directory at {ELYDORA_DIR}: {error}"
+        ) from error
+
+    for entry in entries:
+        try:
+            is_directory = entry.is_dir(follow_symlinks=False)
+        except OSError as error:
+            raise OSError(
+                f"Read Elydora runtime entry at {entry.path}: {error}"
+            ) from error
+        if not is_directory:
+            continue
+
+        guard_path = os.path.join(entry.path, GUARD_SCRIPT)
+        hook_path = os.path.join(entry.path, AUDIT_SCRIPT)
+        if not (
+            _command_references(guard, guard_path)
+            and _command_references(audit, hook_path)
+        ):
+            continue
+
+        config_path = os.path.join(entry.path, "config.json")
+        config = _read_json(config_path, "Elydora runtime config")
+        if config is None:
+            continue
+        agent_name = config.get("agent_name")
+        if not isinstance(agent_name, str):
+            raise ValueError(
+                f'Elydora runtime config at {config_path} field "agent_name" '
+                "must be a string"
+            )
+        if agent_name != AGENT_KEY:
+            continue
+        return _regular_file_exists(
+            guard_path, "Elydora guard runtime"
+        ) and _regular_file_exists(hook_path, "Elydora audit runtime")
+    return False
+
+
+class CodexPlugin(AgentPlugin):
+    """Install Elydora into Codex user lifecycle hooks."""
+
+    def install(self, config: InstallConfig) -> None:
+        agent_id = config.get("agent_id", "")
+        if not agent_id:
+            raise ValueError("agent_id is required")
+
+        existing_settings = _read_json(CONFIG_PATH, "Codex hooks config")
+        settings = (
+            existing_settings
+            if existing_settings is not None
+            else {"description": OWNED_DESCRIPTION}
+        )
+        hooks = _hooks_object(settings)
+        pre_tool_use = _without_elydora(_event_groups(hooks, "PreToolUse"))
+        post_tool_use = _without_elydora(_event_groups(hooks, "PostToolUse"))
+
+        guard_path = config.get("guard_script_path", "")
+        _require_runtime(guard_path, "Elydora guard runtime")
+        agent_dir = os.path.join(ELYDORA_DIR, agent_id)
+        hook_path = os.path.join(agent_dir, AUDIT_SCRIPT)
+        hooks["PreToolUse"] = [
+            *pre_tool_use,
+            {
+                "matcher": "*",
+                "hooks": [_build_handler(guard_path, GUARD_STATUS)],
+            },
+        ]
+        hooks["PostToolUse"] = [
+            *post_tool_use,
+            {
+                "matcher": "*",
+                "hooks": [_build_handler(hook_path, AUDIT_STATUS)],
+            },
+        ]
+
+        runtime_config: JsonObject = {
+            "org_id": config.get("org_id", ""),
+            "agent_id": agent_id,
+            "kid": config.get("kid", ""),
+            "base_url": config.get("base_url", "https://api.elydora.com"),
+            "token": config.get("token", ""),
+            "agent_name": config.get("agent_name", AGENT_KEY) or AGENT_KEY,
+        }
+        hook_script = generate_hook_script(
+            org_id=config.get("org_id", ""),
+            agent_id=agent_id,
+            private_key=config.get("private_key", ""),
+            kid=config.get("kid", ""),
+            base_url=config.get("base_url", "https://api.elydora.com"),
+        )
+        _write_json_atomic(
+            os.path.join(agent_dir, "config.json"),
+            runtime_config,
+            0o600,
+            "Elydora runtime config",
+        )
+        _write_text_atomic(
+            os.path.join(agent_dir, "private.key"),
+            config.get("private_key", ""),
+            0o600,
+            "Elydora private key",
+        )
+        _write_text_atomic(
+            hook_path,
+            hook_script,
+            0o700,
+            "Elydora audit runtime",
+        )
+        _write_json_atomic(
+            CONFIG_PATH,
+            {**settings, "hooks": hooks},
+            0o600,
+            "Codex hooks config",
+        )
+        print("Codex: run /hooks to review and trust the Elydora hooks.")
+
+    def uninstall(self, agent_id: str = "") -> None:
+        settings = _read_json(CONFIG_PATH, "Codex hooks config")
+        if settings is None:
+            return
+        hooks = _hooks_object(settings)
+        hooks["PreToolUse"] = _without_elydora(
+            _event_groups(hooks, "PreToolUse"),
+            agent_id,
+        )
+        hooks["PostToolUse"] = _without_elydora(
+            _event_groups(hooks, "PostToolUse"),
+            agent_id,
+        )
+        if _is_owned_settings(settings, hooks):
+            _remove_file(CONFIG_PATH, "Codex hooks config")
+        else:
+            _write_json_atomic(
+                CONFIG_PATH,
+                {**settings, "hooks": hooks},
+                0o600,
+                "Codex hooks config",
+            )
+
+    def status(self) -> PluginStatus:
+        settings = _read_json(CONFIG_PATH, "Codex hooks config")
+        guard: Optional[JsonObject] = None
+        audit: Optional[JsonObject] = None
+        if settings is not None:
+            hooks = _hooks_object(settings)
+            guard = _find_handler(_event_groups(hooks, "PreToolUse"), GUARD_STATUS)
+            audit = _find_handler(_event_groups(hooks, "PostToolUse"), AUDIT_STATUS)
+
+        if guard is None or audit is None:
+            return PluginStatus(
+                installed=False,
+                agent=AGENT_KEY,
+                details="Not installed",
+            )
+        installed = _runtime_scripts_exist(guard, audit)
+        details = (
+            f"Config: {CONFIG_PATH}"
+            if installed
+            else f"Configured at {CONFIG_PATH}; runtime scripts missing"
+        )
+        return PluginStatus(
+            installed=installed,
+            agent=AGENT_KEY,
+            details=details,
+        )
diff --git a/elydora/plugins/registry.py b/elydora/plugins/registry.py
index 7982674..3b05e85 100644
--- a/elydora/plugins/registry.py
+++ b/elydora/plugins/registry.py
@@ -11,6 +11,11 @@ SUPPORTED_AGENTS: Dict[str, Dict[str, str]] = {
         "hook_event": "PostToolUse",
         "config_path": "~/.claude/settings.json",
     },
+    "codex": {
+        "name": "OpenAI Codex",
+        "hook_event": "PreToolUse/PostToolUse",
+        "config_path": "~/.codex/hooks.json",
+    },
     "copilot": {
         "name": "Copilot CLI",
         "hook_event": "PostToolUse",
diff --git a/tests/test_codex_plugin.py b/tests/test_codex_plugin.py
new file mode 100644
index 0000000..71c3493
--- /dev/null
+++ b/tests/test_codex_plugin.py
@@ -0,0 +1,411 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+import json
+import os
+from pathlib import Path
+import subprocess
+from typing import Any
+
+import pytest
+
+from elydora.plugins import codex
+from elydora.plugins.base import InstallConfig
+from elydora.plugins.registry import SUPPORTED_AGENTS
+
+
+AGENT_ID = "agent-1"
+MISSING = object()
+GUARD_STATUS = "Checking Elydora agent state"
+AUDIT_STATUS = "Recording Elydora tool use"
+
+
+@dataclass(frozen=True)
+class CodexFixture:
+    plugin: codex.CodexPlugin
+    config: InstallConfig
+    home_dir: Path
+    agent_dir: Path
+    config_path: Path
+    guard_path: Path
+    hook_path: Path
+    runtime_config_path: Path
+    private_key_path: Path
+
+
+def write_json_or_text(path: Path, value: Any) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    content = value if isinstance(value, str) else json.dumps(value, indent=2)
+    path.write_text(content, encoding="utf-8")
+
+
+def prepare_fixture(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+    *,
+    existing_settings: Any = MISSING,
+    create_guard: bool = True,
+) -> CodexFixture:
+    home_dir = tmp_path / "home with spaces"
+    elydora_dir = home_dir / ".elydora"
+    agent_dir = elydora_dir / AGENT_ID
+    config_path = home_dir / ".codex" / "hooks.json"
+    agent_dir.mkdir(parents=True)
+
+    guard_path = agent_dir / "guard.py"
+    if create_guard:
+        guard_path.write_text(
+            "import sys\nsys.stderr.write('Agent is frozen by Elydora.')\n"
+            "raise SystemExit(2)\n",
+            encoding="utf-8",
+        )
+    if existing_settings is not MISSING:
+        write_json_or_text(config_path, existing_settings)
+
+    monkeypatch.setattr(codex, "ELYDORA_DIR", str(elydora_dir))
+    monkeypatch.setattr(codex, "CONFIG_PATH", str(config_path))
+    config: InstallConfig = {
+        "agent_id": AGENT_ID,
+        "agent_name": "codex",
+        "org_id": "org-1",
+        "private_key": "test-key",
+        "kid": "kid-1",
+        "base_url": "https://api.elydora.test",
+        "guard_script_path": str(guard_path),
+    }
+    return CodexFixture(
+        plugin=codex.CodexPlugin(),
+        config=config,
+        home_dir=home_dir,
+        agent_dir=agent_dir,
+        config_path=config_path,
+        guard_path=guard_path,
+        hook_path=agent_dir / "hook.py",
+        runtime_config_path=agent_dir / "config.json",
+        private_key_path=agent_dir / "private.key",
+    )
+
+
+def find_handler(
+    settings: dict[str, Any],
+    event: str,
+    status_message: str,
+) -> dict[str, Any]:
+    for group in settings["hooks"][event]:
+        for handler in group["hooks"]:
+            if handler.get("statusMessage") == status_message:
+                return handler
+    raise AssertionError(f"handler {status_message!r} not found")
+
+
+def run_command(
+    command: str,
+    home_dir: Path,
+    payload: dict[str, Any],
+) -> subprocess.CompletedProcess[str]:
+    env = {
+        **os.environ,
+        "HOME": str(home_dir),
+        "USERPROFILE": str(home_dir),
+    }
+    return subprocess.run(
+        command,
+        shell=True,
+        capture_output=True,
+        check=False,
+        env=env,
+        input=json.dumps(payload),
+        text=True,
+    )
+
+
+def test_codex_registry_points_at_global_hooks_contract() -> None:
+    assert SUPPORTED_AGENTS["codex"] == {
+        "name": "OpenAI Codex",
+        "hook_event": "PreToolUse/PostToolUse",
+        "config_path": "~/.codex/hooks.json",
+    }
+
+
+def test_install_preserves_existing_hooks_and_is_idempotent(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    fixture = prepare_fixture(
+        monkeypatch,
+        tmp_path,
+        existing_settings={
+            "description": "Workspace hooks",
+            "hooks": {
+                "SessionStart": [{
+                    "hooks": [{"type": "command", "command": "existing-command"}],
+                }],
+            },
+        },
+    )
+
+    fixture.plugin.install(fixture.config)
+    fixture.plugin.install(fixture.config)
+
+    assert "run /hooks to review and trust" in capsys.readouterr().out
+    settings = json.loads(fixture.config_path.read_text(encoding="utf-8"))
+    assert settings["description"] == "Workspace hooks"
+    assert settings["hooks"]["SessionStart"][0]["hooks"][0]["command"] == "existing-command"
+    assert len(settings["hooks"]["PreToolUse"]) == 1
+    assert len(settings["hooks"]["PostToolUse"]) == 1
+    assert settings["hooks"]["PreToolUse"][0]["matcher"] == "*"
+    guard = find_handler(settings, "PreToolUse", GUARD_STATUS)
+    assert guard["type"] == "command"
+    assert guard["timeout"] == 10
+    assert isinstance(guard["command"], str)
+    assert isinstance(guard["commandWindows"], str)
+
+
+def test_commands_block_frozen_agents_and_forward_official_payload(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.plugin.install(fixture.config)
+    capture_path = tmp_path / "captured-event.json"
+    fixture.hook_path.write_text(
+        "import pathlib, sys\n"
+        f"pathlib.Path({str(capture_path)!r}).write_text(sys.stdin.read(), encoding='utf-8')\n",
+        encoding="utf-8",
+    )
+    settings = json.loads(fixture.config_path.read_text(encoding="utf-8"))
+    command_key = "commandWindows" if os.name == "nt" else "command"
+    payload = {
+        "hook_event_name": "PreToolUse",
+        "session_id": "session-1",
+        "turn_id": "turn-1",
+        "transcript_path": None,
+        "cwd": str(fixture.home_dir),
+        "model": "gpt-5",
+        "permission_mode": "default",
+        "tool_name": "Bash",
+        "tool_use_id": "call-1",
+        "tool_input": {"command": "echo test"},
+    }
+
+    guard = find_handler(settings, "PreToolUse", GUARD_STATUS)
+    guard_result = run_command(guard[command_key], fixture.home_dir, payload)
+    assert guard_result.returncode == 2
+    assert "Agent is frozen by Elydora" in guard_result.stderr
+
+    payload["hook_event_name"] = "PostToolUse"
+    payload["tool_response"] = {"output": "test"}
+    audit = find_handler(settings, "PostToolUse", AUDIT_STATUS)
+    audit_result = run_command(audit[command_key], fixture.home_dir, payload)
+    assert audit_result.returncode == 0
+    assert json.loads(capture_path.read_text(encoding="utf-8")) == payload
+
+
+def test_status_requires_both_runtimes_and_uninstall_preserves_other_hooks(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    existing_handler = {"type": "command", "command": "existing-command"}
+    fixture = prepare_fixture(
+        monkeypatch,
+        tmp_path,
+        existing_settings={
+            "hooks": {"PreToolUse": [{"hooks": [existing_handler]}]},
+        },
+    )
+    fixture.plugin.install(fixture.config)
+    assert fixture.plugin.status() == {
+        "installed": True,
+        "agent": "codex",
+        "details": f"Config: {fixture.config_path}",
+    }
+
+    fixture.guard_path.unlink()
+    assert fixture.plugin.status() == {
+        "installed": False,
+        "agent": "codex",
+        "details": f"Configured at {fixture.config_path}; runtime scripts missing",
+    }
+
+    fixture.plugin.uninstall(AGENT_ID)
+    settings = json.loads(fixture.config_path.read_text(encoding="utf-8"))
+    assert settings["hooks"]["PreToolUse"] == [{"hooks": [existing_handler]}]
+    assert settings["hooks"]["PostToolUse"] == []
+
+
+def test_install_preserves_user_handlers_with_matching_status_text(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    user_guard = {
+        "type": "command",
+        "command": "user-guard",
+        "statusMessage": GUARD_STATUS,
+    }
+    user_audit = {
+        "type": "command",
+        "command": "user-audit",
+        "statusMessage": AUDIT_STATUS,
+    }
+    fixture = prepare_fixture(
+        monkeypatch,
+        tmp_path,
+        existing_settings={
+            "hooks": {
+                "PreToolUse": [{"matcher": "Bash", "hooks": [user_guard]}],
+                "PostToolUse": [{"matcher": "Bash", "hooks": [user_audit]}],
+            },
+        },
+    )
+
+    fixture.plugin.install(fixture.config)
+
+    settings = json.loads(fixture.config_path.read_text(encoding="utf-8"))
+    assert settings["hooks"]["PreToolUse"][0]["hooks"][0] == user_guard
+    assert settings["hooks"]["PostToolUse"][0]["hooks"][0] == user_audit
+    assert len(settings["hooks"]["PreToolUse"]) == 2
+    assert len(settings["hooks"]["PostToolUse"]) == 2
+
+
+def test_install_rejects_missing_guard_before_runtime_or_config_writes(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path, create_guard=False)
+
+    with pytest.raises(FileNotFoundError, match="guard runtime is missing"):
+        fixture.plugin.install(fixture.config)
+
+    assert fixture.config_path.exists() is False
+    assert fixture.hook_path.exists() is False
+    assert fixture.runtime_config_path.exists() is False
+    assert fixture.private_key_path.exists() is False
+
+
+def test_status_surfaces_malformed_referenced_runtime_metadata(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.plugin.install(fixture.config)
+    fixture.runtime_config_path.write_text("{ malformed", encoding="utf-8")
+
+    with pytest.raises(ValueError, match="parse Elydora runtime config"):
+        fixture.plugin.status()
+
+
+def test_status_surfaces_malformed_matcher_groups(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.plugin.install(fixture.config)
+    settings = json.loads(fixture.config_path.read_text(encoding="utf-8"))
+    settings["hooks"]["PreToolUse"][0]["hooks"] = None
+    fixture.config_path.write_text(json.dumps(settings), encoding="utf-8")
+
+    with pytest.raises(ValueError, match="matcher group must contain a hooks array"):
+        fixture.plugin.status()
+
+
+def test_uninstall_removes_config_owned_entirely_by_elydora(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.plugin.install(fixture.config)
+
+    fixture.plugin.uninstall(AGENT_ID)
+
+    assert fixture.config_path.exists() is False
+
+
+def test_uninstall_matches_the_exact_agent_runtime_directory(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(monkeypatch, tmp_path)
+    fixture.plugin.install(fixture.config)
+    settings = json.loads(fixture.config_path.read_text(encoding="utf-8"))
+    other_agent_dir = fixture.agent_dir.parent / "agent-10"
+
+    for event, status in (
+        ("PreToolUse", GUARD_STATUS),
+        ("PostToolUse", AUDIT_STATUS),
+    ):
+        handler = find_handler(settings, event, status)
+        other_handler = {
+            **handler,
+            "command": handler["command"].replace(
+                str(fixture.agent_dir), str(other_agent_dir)
+            ),
+            "commandWindows": handler["commandWindows"].replace(
+                str(fixture.agent_dir), str(other_agent_dir)
+            ),
+        }
+        settings["hooks"][event].append(
+            {"matcher": "*", "hooks": [other_handler]}
+        )
+    fixture.config_path.write_text(json.dumps(settings), encoding="utf-8")
+
+    fixture.plugin.uninstall(AGENT_ID)
+
+    remaining = json.loads(fixture.config_path.read_text(encoding="utf-8"))
+    assert len(remaining["hooks"]["PreToolUse"]) == 1
+    assert len(remaining["hooks"]["PostToolUse"]) == 1
+    assert str(other_agent_dir) in find_handler(
+        remaining, "PreToolUse", GUARD_STATUS
+    )["command"]
+
+
+@pytest.mark.parametrize(
+    ("existing_settings", "error_pattern"),
+    [
+        ({"hooks": None}, 'field "hooks" must be an object'),
+        ({"hooks": {"PreToolUse": None}}, 'field "hooks.PreToolUse" must be an array'),
+        (
+            {"hooks": {"PreToolUse": [{"hooks": None}]}},
+            "matcher group must contain a hooks array",
+        ),
+    ],
+)
+def test_install_preserves_invalid_shapes_before_runtime_writes(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+    existing_settings: dict[str, Any],
+    error_pattern: str,
+) -> None:
+    fixture = prepare_fixture(
+        monkeypatch,
+        tmp_path,
+        existing_settings=existing_settings,
+    )
+    original = fixture.config_path.read_text(encoding="utf-8")
+
+    with pytest.raises(ValueError, match=error_pattern):
+        fixture.plugin.install(fixture.config)
+
+    assert fixture.config_path.read_text(encoding="utf-8") == original
+    assert fixture.hook_path.exists() is False
+    assert fixture.runtime_config_path.exists() is False
+    assert fixture.private_key_path.exists() is False
+
+
+def test_install_preserves_malformed_config_before_runtime_writes(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    fixture = prepare_fixture(
+        monkeypatch,
+        tmp_path,
+        existing_settings="{ malformed",
+    )
+
+    with pytest.raises(ValueError, match="parse Codex hooks config"):
+        fixture.plugin.install(fixture.config)
+
+    assert fixture.config_path.read_text(encoding="utf-8") == "{ malformed"
+    assert fixture.hook_path.exists() is False
+    assert fixture.runtime_config_path.exists() is False
+    assert fixture.private_key_path.exists() is False