diff --git a/Resources/shell-integration/cmux-zsh-integration.zsh b/Resources/shell-integration/cmux-zsh-integration.zsh
index a9f1137a..988be2f1 100644
--- a/Resources/shell-integration/cmux-zsh-integration.zsh
+++ b/Resources/shell-integration/cmux-zsh-integration.zsh
@@ -46,6 +46,7 @@ typeset -g _CMUX_GIT_FORCE=0
 typeset -g _CMUX_GIT_HEAD_LAST_PWD=""
 typeset -g _CMUX_GIT_HEAD_PATH=""
 typeset -g _CMUX_GIT_HEAD_MTIME=0
+typeset -g _CMUX_GIT_HEAD_WATCH_PID=""
 typeset -g _CMUX_HAVE_ZSTAT=0
 typeset -g _CMUX_PR_LAST_PWD=""
 typeset -g _CMUX_PR_LAST_RUN=0
@@ -148,6 +149,65 @@ _cmux_ports_kick() {
     } >/dev/null 2>&1 &!
 }
 
+_cmux_report_git_branch_for_path() {
+    local repo_path="$1"
+    [[ -n "$repo_path" ]] || return 0
+    [[ -S "$CMUX_SOCKET_PATH" ]] || return 0
+    [[ -n "$CMUX_TAB_ID" ]] || return 0
+    [[ -n "$CMUX_PANEL_ID" ]] || return 0
+
+    local branch dirty_opt="" first
+    branch="$(git -C "$repo_path" branch --show-current 2>/dev/null)"
+    if [[ -n "$branch" ]]; then
+        first="$(git -C "$repo_path" status --porcelain -uno 2>/dev/null | head -1)"
+        [[ -n "$first" ]] && dirty_opt="--status=dirty"
+        _cmux_send "report_git_branch $branch $dirty_opt --tab=$CMUX_TAB_ID --panel=$CMUX_PANEL_ID"
+    else
+        _cmux_send "clear_git_branch --tab=$CMUX_TAB_ID --panel=$CMUX_PANEL_ID"
+    fi
+}
+
+_cmux_stop_git_head_watch() {
+    if [[ -n "$_CMUX_GIT_HEAD_WATCH_PID" ]]; then
+        kill "$_CMUX_GIT_HEAD_WATCH_PID" >/dev/null 2>&1 || true
+        _CMUX_GIT_HEAD_WATCH_PID=""
+    fi
+}
+
+_cmux_start_git_head_watch() {
+    [[ -S "$CMUX_SOCKET_PATH" ]] || return 0
+    [[ -n "$CMUX_TAB_ID" ]] || return 0
+    [[ -n "$CMUX_PANEL_ID" ]] || return 0
+
+    local watch_pwd="$PWD"
+    local watch_head_path
+    watch_head_path="$(_cmux_git_resolve_head_path 2>/dev/null || true)"
+    [[ -n "$watch_head_path" ]] || return 0
+
+    local watch_head_mtime
+    watch_head_mtime="$(_cmux_git_head_mtime "$watch_head_path" 2>/dev/null || echo 0)"
+
+    _CMUX_GIT_HEAD_LAST_PWD="$watch_pwd"
+    _CMUX_GIT_HEAD_PATH="$watch_head_path"
+    _CMUX_GIT_HEAD_MTIME="$watch_head_mtime"
+
+    _cmux_stop_git_head_watch
+    {
+        local last_mtime="$watch_head_mtime"
+        while true; do
+            sleep 1
+
+            local mtime
+            mtime="$(_cmux_git_head_mtime "$watch_head_path" 2>/dev/null || echo 0)"
+            if [[ -n "$mtime" && "$mtime" != 0 && "$mtime" != "$last_mtime" ]]; then
+                last_mtime="$mtime"
+                _cmux_report_git_branch_for_path "$watch_pwd"
+            fi
+        done
+    } >/dev/null 2>&1 &!
+    _CMUX_GIT_HEAD_WATCH_PID=$!
+}
+
 _cmux_preexec() {
     if [[ -z "$_CMUX_TTY_NAME" ]]; then
         local t
@@ -169,9 +229,12 @@ _cmux_preexec() {
     # Register TTY + kick batched port scan for foreground commands (servers).
     _cmux_report_tty_once
     _cmux_ports_kick
+    _cmux_start_git_head_watch
 }
 
 _cmux_precmd() {
+    _cmux_stop_git_head_watch
+
     # Skip if socket doesn't exist yet
     [[ -S "$CMUX_SOCKET_PATH" ]] || return 0
     [[ -n "$CMUX_TAB_ID" ]] || return 0
@@ -227,6 +290,8 @@ _cmux_precmd() {
     fi
 
     # Git branch/dirty: update immediately on directory change, otherwise every ~3s.
+    # While a foreground command is running, _cmux_start_git_head_watch probes HEAD
+    # once per second so agent-initiated git checkouts still surface quickly.
     local should_git=0
 
     # Git branch can change without a `git ...`-prefixed command (aliases like `gco`,
@@ -280,16 +345,7 @@ _cmux_precmd() {
             _CMUX_GIT_LAST_PWD="$pwd"
             _CMUX_GIT_LAST_RUN=$now
             {
-                local branch dirty_opt=""
-                branch=$(git branch --show-current 2>/dev/null)
-                if [[ -n "$branch" ]]; then
-                    local first
-                    first=$(git status --porcelain -uno 2>/dev/null | head -1)
-                    [[ -n "$first" ]] && dirty_opt="--status=dirty"
-                    _cmux_send "report_git_branch $branch $dirty_opt --tab=$CMUX_TAB_ID --panel=$CMUX_PANEL_ID"
-                else
-                    _cmux_send "clear_git_branch --tab=$CMUX_TAB_ID --panel=$CMUX_PANEL_ID"
-                fi
+                _cmux_report_git_branch_for_path "$pwd"
             } >/dev/null 2>&1 &!
             _CMUX_GIT_JOB_PID=$!
             _CMUX_GIT_JOB_STARTED_AT=$now
@@ -387,7 +443,12 @@ _cmux_fix_path() {
     add-zsh-hook -d precmd _cmux_fix_path
 }
 
+_cmux_zshexit() {
+    _cmux_stop_git_head_watch
+}
+
 autoload -Uz add-zsh-hook
 add-zsh-hook preexec _cmux_preexec
 add-zsh-hook precmd _cmux_precmd
 add-zsh-hook precmd _cmux_fix_path
+add-zsh-hook zshexit _cmux_zshexit
diff --git a/tests/test_sidebar_cwd_git.py b/tests/test_sidebar_cwd_git.py
index e6168a1f..520a0831 100644
--- a/tests/test_sidebar_cwd_git.py
+++ b/tests/test_sidebar_cwd_git.py
@@ -72,6 +72,7 @@ def _wait_for_git_branch(
     expected: str,
     timeout: float = 12.0,
     interval: float = 0.15,
+    allow_force_fallback: bool = True,
 ) -> dict[str, str]:
     def pred():
         state = _parse_sidebar_state(client.sidebar_state())
@@ -82,6 +83,8 @@ def _wait_for_git_branch(
     try:
         return _wait_for(pred, timeout=timeout, interval=interval, label=f"git_branch={expected!r}")
     except AssertionError as original_error:
+        if not allow_force_fallback:
+            raise original_error
         # VM shells can occasionally skip a prompt hook; force a one-shot report so
         # the remainder of the flow can still validate transition behavior.
         try:
@@ -180,6 +183,18 @@ def main() -> int:
             _send_cd_and_wait(client, repo)
             _wait_for_git_branch(client, "main")
 
+            # Branch changes during a long-running foreground command should still
+            # propagate before the prompt returns (agent-style workflows).
+            client.send("bash -lc 'git checkout -b feature/agent-live >/dev/null 2>&1; sleep 6'\n")
+            _wait_for_git_branch(
+                client,
+                "feature/agent-live",
+                timeout=3.5,
+                interval=0.1,
+                allow_force_fallback=False,
+            )
+            time.sleep(6.3)
+
             # Branch change should update.
             # Cover alias/non-`git ...` command paths too (regression: branch could
             # stick for ~3s when switching via alias/tools like `gh pr checkout`).