diff --git a/.agents/plugins/marketplace.json b/.agents/plugins/marketplace.json
index e05e08b..c68248b 100644
--- a/.agents/plugins/marketplace.json
+++ b/.agents/plugins/marketplace.json
@@ -14,7 +14,7 @@
         "installation": "AVAILABLE",
         "authentication": "ON_INSTALL"
       },
-      "version": "0.4.0",
+      "version": "0.4.1",
       "category": "productivity",
       "tags": ["notifications", "terminal", "warp"]
     },
@@ -26,7 +26,7 @@
         "installation": "AVAILABLE",
         "authentication": "ON_INSTALL"
       },
-      "version": "0.4.0",
+      "version": "0.4.1",
       "category": "productivity",
       "tags": ["terminal", "warp", "oz"]
     }
diff --git a/README.md b/README.md
index 000240a..c4b1c9a 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,8 @@ tests/test-hooks.sh                       Shell tests
 ## Plugins
 - `warp`: `SessionStart`, `Stop`, `PermissionRequest`, `UserPromptSubmit`, `PostToolUse` notifications for Warp.
 - `orchestration`: `SessionStart`, `UserPromptSubmit`, `PostToolUse`, `Stop`, `SessionEnd` parent-message delivery for Codex child runs, plus Oz skills.
-Hook commands use `${PLUGIN_ROOT}/scripts/...`.
+Hook commands use `${CLAUDE_PLUGIN_ROOT}/scripts/...`, the plugin root provided by
+Codex.
 ## Local install
 ```sh
 codex plugin marketplace add .
@@ -33,7 +34,7 @@ This uses a fake `oz` CLI and a temp `CODEX_HOME`.
 It validates parent-message staging/drain/blocking and plugin manifests.
 ## Versioning
 `plugins/warp/scripts/on-session-start.sh` emits `PLUGIN_VERSION`.
-Current plugin version: `0.4.0`.
+Current plugin version: `0.4.1`.
 Keep it in sync with Warp's Codex plugin manager minimum version.
 ## Skills
 
diff --git a/plugins/orchestration/.codex-plugin/plugin.json b/plugins/orchestration/.codex-plugin/plugin.json
index d97c805..0f09daf 100644
--- a/plugins/orchestration/.codex-plugin/plugin.json
+++ b/plugins/orchestration/.codex-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "orchestration",
   "description": "Warp integration for Codex in Oz cloud agent environments, including parent-message delivery hooks and skills",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "author": {
     "name": "Warp",
     "url": "https://warp.dev"
diff --git a/plugins/orchestration/hooks/hooks.json b/plugins/orchestration/hooks/hooks.json
index 165b7cf..a7e6014 100644
--- a/plugins/orchestration/hooks/hooks.json
+++ b/plugins/orchestration/hooks/hooks.json
@@ -5,7 +5,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-session-start.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-session-start.sh\""
           }
         ]
       }
@@ -15,7 +15,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/drain-mailbox.sh UserPromptSubmit"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/drain-mailbox.sh\" UserPromptSubmit"
           }
         ]
       }
@@ -26,7 +26,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/drain-mailbox.sh PostToolUse"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/drain-mailbox.sh\" PostToolUse"
           }
         ]
       }
@@ -36,7 +36,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-stop.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-stop.sh\""
           }
         ]
       }
@@ -46,7 +46,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-session-end.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-session-end.sh\""
           }
         ]
       }
diff --git a/plugins/warp/.codex-plugin/plugin.json b/plugins/warp/.codex-plugin/plugin.json
index ebe510d..4020360 100644
--- a/plugins/warp/.codex-plugin/plugin.json
+++ b/plugins/warp/.codex-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "warp",
   "description": "Warp terminal integration for Codex - native notifications, and more to come",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "author": {
     "name": "Warp",
     "url": "https://warp.dev"
diff --git a/plugins/warp/hooks/hooks.json b/plugins/warp/hooks/hooks.json
index ce26297..ebcd3aa 100644
--- a/plugins/warp/hooks/hooks.json
+++ b/plugins/warp/hooks/hooks.json
@@ -5,7 +5,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-session-start.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-session-start.sh\""
           }
         ]
       }
@@ -15,7 +15,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-stop.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-stop.sh\""
           }
         ]
       }
@@ -25,7 +25,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-permission-request.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-permission-request.sh\""
           }
         ]
       }
@@ -35,7 +35,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-prompt-submit.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-prompt-submit.sh\""
           }
         ]
       }
@@ -45,7 +45,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "${PLUGIN_ROOT}/scripts/on-post-tool-use.sh"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/on-post-tool-use.sh\""
           }
         ]
       }
diff --git a/plugins/warp/scripts/on-session-start.sh b/plugins/warp/scripts/on-session-start.sh
index af5fb59..cf72380 100755
--- a/plugins/warp/scripts/on-session-start.sh
+++ b/plugins/warp/scripts/on-session-start.sh
@@ -5,7 +5,7 @@
 set -euo pipefail
 
 # Bump on every release; keep in sync with Warp's Codex plugin manager.
-PLUGIN_VERSION="0.4.0"
+PLUGIN_VERSION="0.4.1"
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 source "$SCRIPT_DIR/should-use-structured.sh"
diff --git a/tests/test-hooks.sh b/tests/test-hooks.sh
index e54738c..8805cb3 100755
--- a/tests/test-hooks.sh
+++ b/tests/test-hooks.sh
@@ -228,11 +228,51 @@ assert_file_exists "github workflow exists" "$REPO_ROOT/.github/workflows/test.y
 assert_json_field "marketplace name" "$(cat "$REPO_ROOT/.agents/plugins/marketplace.json")" ".name" "codex-warp"
 assert_json_field "warp plugin name" "$(cat "$REPO_ROOT/plugins/warp/.codex-plugin/plugin.json")" ".name" "warp"
 assert_json_field "oz plugin name" "$(cat "$REPO_ROOT/plugins/orchestration/.codex-plugin/plugin.json")" ".name" "orchestration"
-assert_contains "warp hooks use PLUGIN_ROOT" "$(cat "$REPO_ROOT/plugins/warp/hooks/hooks.json")" '${PLUGIN_ROOT}/scripts/on-session-start.sh'
-assert_contains "warp hooks include prompt submit" "$(cat "$REPO_ROOT/plugins/warp/hooks/hooks.json")" '${PLUGIN_ROOT}/scripts/on-prompt-submit.sh'
-assert_contains "warp hooks include post tool use" "$(cat "$REPO_ROOT/plugins/warp/hooks/hooks.json")" '${PLUGIN_ROOT}/scripts/on-post-tool-use.sh'
-assert_contains "oz hooks use PLUGIN_ROOT" "$(cat "$REPO_ROOT/plugins/orchestration/hooks/hooks.json")" '${PLUGIN_ROOT}/scripts/drain-mailbox.sh UserPromptSubmit'
-assert_contains "oz hooks include session end" "$(cat "$REPO_ROOT/plugins/orchestration/hooks/hooks.json")" '${PLUGIN_ROOT}/scripts/on-session-end.sh'
+assert_contains "warp hooks use CLAUDE_PLUGIN_ROOT" "$(cat "$REPO_ROOT/plugins/warp/hooks/hooks.json")" '${CLAUDE_PLUGIN_ROOT}/scripts/on-session-start.sh'
+assert_contains "warp hooks include prompt submit" "$(cat "$REPO_ROOT/plugins/warp/hooks/hooks.json")" '${CLAUDE_PLUGIN_ROOT}/scripts/on-prompt-submit.sh'
+assert_contains "warp hooks include post tool use" "$(cat "$REPO_ROOT/plugins/warp/hooks/hooks.json")" '${CLAUDE_PLUGIN_ROOT}/scripts/on-post-tool-use.sh'
+assert_contains "oz hooks use CLAUDE_PLUGIN_ROOT" "$(cat "$REPO_ROOT/plugins/orchestration/hooks/hooks.json")" '${CLAUDE_PLUGIN_ROOT}/scripts/drain-mailbox.sh'
+assert_contains "oz hooks include session end" "$(cat "$REPO_ROOT/plugins/orchestration/hooks/hooks.json")" '${CLAUDE_PLUGIN_ROOT}/scripts/on-session-end.sh'
+
+echo ""
+echo "=== Codex plugin root contract ==="
+unset OZ_PARENT_RUN_ID
+WARP_PLUGIN_ROOT="$TEST_TMP/warp plugin with spaces"
+ORCHESTRATION_PLUGIN_ROOT="$TEST_TMP/orchestration plugin with spaces"
+ln -s "$REPO_ROOT/plugins/warp" "$WARP_PLUGIN_ROOT"
+ln -s "$REPO_ROOT/plugins/orchestration" "$ORCHESTRATION_PLUGIN_ROOT"
+WARP_HOOKS="$WARP_PLUGIN_ROOT/hooks/hooks.json"
+ORCHESTRATION_HOOKS="$ORCHESTRATION_PLUGIN_ROOT/hooks/hooks.json"
+SESSION_START_COMMAND=$(jq -r '.hooks.SessionStart[0].hooks[0].command' "$WARP_HOOKS")
+STOP_COMMAND=$(jq -r '.hooks.Stop[0].hooks[0].command' "$WARP_HOOKS")
+ORCHESTRATION_START_COMMAND=$(jq -r '.hooks.SessionStart[0].hooks[0].command' "$ORCHESTRATION_HOOKS")
+ORCHESTRATION_STOP_COMMAND=$(jq -r '.hooks.Stop[0].hooks[0].command' "$ORCHESTRATION_HOOKS")
+
+OUTPUT=$(printf '%s' "$HOOK_INPUT" | env -u PLUGIN_ROOT \
+    -u WARP_CLI_AGENT_PROTOCOL_VERSION -u WARP_CLIENT_VERSION \
+    CLAUDE_PLUGIN_ROOT="$WARP_PLUGIN_ROOT" sh -c "$SESSION_START_COMMAND")
+STATUS=$?
+assert_eq "session start resolves CLAUDE_PLUGIN_ROOT" "0" "$STATUS"
+assert_eq "session start stays silent outside Warp" "" "$OUTPUT"
+
+OUTPUT=$(printf '%s' "$HOOK_INPUT" | env -u PLUGIN_ROOT \
+    -u WARP_CLI_AGENT_PROTOCOL_VERSION -u WARP_CLIENT_VERSION \
+    CLAUDE_PLUGIN_ROOT="$WARP_PLUGIN_ROOT" sh -c "$STOP_COMMAND")
+STATUS=$?
+assert_eq "stop resolves CLAUDE_PLUGIN_ROOT" "0" "$STATUS"
+assert_eq "stop stays silent outside Warp" "" "$OUTPUT"
+
+OUTPUT=$(printf '%s' "$HOOK_INPUT" | env -u PLUGIN_ROOT -u OZ_PARENT_RUN_ID \
+    CLAUDE_PLUGIN_ROOT="$ORCHESTRATION_PLUGIN_ROOT" sh -c "$ORCHESTRATION_START_COMMAND")
+STATUS=$?
+assert_eq "orchestration start resolves CLAUDE_PLUGIN_ROOT" "0" "$STATUS"
+assert_eq "orchestration start stays silent outside Oz" "" "$OUTPUT"
+
+OUTPUT=$(printf '%s' "$HOOK_INPUT" | env -u PLUGIN_ROOT -u OZ_PARENT_RUN_ID \
+    CLAUDE_PLUGIN_ROOT="$ORCHESTRATION_PLUGIN_ROOT" sh -c "$ORCHESTRATION_STOP_COMMAND")
+STATUS=$?
+assert_eq "orchestration stop resolves CLAUDE_PLUGIN_ROOT" "0" "$STATUS"
+assert_eq "orchestration stop stays silent outside Oz" "" "$OUTPUT"
 
 
 echo ""