diff --git a/scripts/despawn.sh b/scripts/despawn.sh
index 8f5fc4ed..31f3bf05 100755
--- a/scripts/despawn.sh
+++ b/scripts/despawn.sh
@@ -50,13 +50,36 @@ case "$TIMEOUT" in ''|*[!0-9]*) die "--timeout must be a whole number of seconds
 
 SPAWN_REC="$(agmsg_spawn_path "$TEAM" "$NAME")"
 
-# Kill the recorded tmux target. ids are self-describing: %N pane, @N window.
+# Kill the recorded placement. ids are self-describing: %N/@N for tmux,
+# herdr:<id> for herdr, and pid:<N> for an OS-terminal boot process.
+kill_pid_tree() {
+  local pid="$1" child children
+  case "$pid" in ''|*[!0-9]*) return 1 ;; esac
+  # pgrep -P is available on both macOS and Linux. Keep a ps fallback for
+  # minimal environments where procps is present without pgrep.
+  if command -v pgrep >/dev/null 2>&1; then
+    children="$(pgrep -P "$pid" 2>/dev/null || true)"
+  else
+    children="$(ps -o pid= --ppid "$pid" 2>/dev/null || true)"
+  fi
+  # Stop descendants before their boot-shell parent. This works for terminal
+  # templates that do not make the boot script a process-group leader.
+  while IFS= read -r child; do
+    child="${child//[[:space:]]/}"
+    [ -n "$child" ] && kill_pid_tree "$child"
+  done <<< "$children"
+  kill "$pid" 2>/dev/null || true
+}
+
 kill_recorded_placement() {
   [ -f "$SPAWN_REC" ] || return 1
   local id _proj _type
   IFS=$'\t' read -r id _proj _type < "$SPAWN_REC"
   [ -n "$id" ] || return 1
   case "$id" in
+    pid:*)
+      kill_pid_tree "${id#pid:}" || true
+      ;;
     herdr:*)
       command -v herdr >/dev/null 2>&1 && herdr pane close "${id#herdr:}" 2>/dev/null || true
       ;;
@@ -91,6 +114,23 @@ fi
 state="$(actas_lock_state "$TEAM" "$NAME" "" 2>/dev/null || echo free)"
 case "$state" in
   free)
+    if [ -f "$SPAWN_REC" ]; then
+      IFS=$'\t' read -r _id _proj _type < "$SPAWN_REC"
+      case "${_id:-}" in
+        pid:*)
+          # OS-terminal members (notably codex) may have no watcher/actas lock.
+          # The boot PID is still an owned placement, so graceful despawn can
+          # terminate it and consistently remove the pre-joined registration.
+          kill_recorded_placement >/dev/null
+          if [ -n "${_proj:-}" ] && [ -n "${_type:-}" ]; then
+            "$SCRIPT_DIR/reset.sh" "$_proj" "$_type" "$NAME" >/dev/null 2>&1 || true
+          fi
+          rm -f "$SPAWN_REC" 2>/dev/null || true
+          echo "status=ok name=$NAME team=$TEAM note=os-terminal"
+          exit 0
+          ;;
+      esac
+    fi
     echo "despawn: '$NAME' holds no live actas lock — nothing to confirm a teardown against (a codex member has no watcher; a tmux member may already be gone). If a window remains, use --force." >&2
     rm -f "$SPAWN_REC" 2>/dev/null || true
     echo "status=ok name=$NAME team=$TEAM note=no-live-lock"
@@ -113,5 +153,19 @@ while true; do
   waited=$((waited + 1))
 done
 
+# A graceful OS-terminal watcher can release its role but cannot portably close
+# the containing terminal. Once the lock is gone, use the boot PID placement to
+# finish teardown and make registration cleanup idempotent from the leader side.
+if [ -f "$SPAWN_REC" ]; then
+  IFS=$'\t' read -r _id _proj _type < "$SPAWN_REC"
+  case "${_id:-}" in
+    pid:*)
+      kill_recorded_placement >/dev/null
+      if [ -n "${_proj:-}" ] && [ -n "${_type:-}" ]; then
+        "$SCRIPT_DIR/reset.sh" "$_proj" "$_type" "$NAME" >/dev/null 2>&1 || true
+      fi
+      ;;
+  esac
+fi
 rm -f "$SPAWN_REC" 2>/dev/null || true
 echo "status=ok name=$NAME team=$TEAM after=${waited}s"
diff --git a/scripts/spawn.sh b/scripts/spawn.sh
index 976edbd9..8f6af611 100755
--- a/scripts/spawn.sh
+++ b/scripts/spawn.sh
@@ -426,6 +426,16 @@ BOOT="$(mktemp "$BOOT_DIR/boot-XXXXXX")"
 case "$(uname -s)" in
   Darwin) mv "$BOOT" "$BOOT.command"; BOOT="$BOOT.command" ;;
 esac
+
+# Tmux/herdr have stable native placement identifiers that their launchers
+# record below. An OS terminal has no portable window handle, so let the boot
+# script record its own PID instead; despawn can then terminate that process
+# tree and still has the project/type metadata needed to drop registration.
+RECORD_BOOT_PID=1
+if [ -n "${TMUX:-}" ] \
+  || { [ "${HERDR_ENV:-}" = "1" ] && [ -n "${HERDR_PANE_ID:-}" ] && command -v herdr >/dev/null 2>&1; }; then
+  RECORD_BOOT_PID=0
+fi
 {
   echo '#!/usr/bin/env bash'
   printf 'cd %q || exit 1\n' "$PROJECT"
@@ -433,6 +443,12 @@ esac
   # actas flow knows the session is already named <team>-<agent> (name_arg) and
   # suppresses the "rename this session" tip meant for hand-started sessions.
   echo 'export AGMSG_SPAWNED=1'
+  if [ "$RECORD_BOOT_PID" = "1" ]; then
+    _spawn_rec="$(agmsg_spawn_path "$TEAM" "$NAME")"
+    printf 'mkdir -p %q\n' "$(dirname "$_spawn_rec")"
+    printf 'printf %q "pid:$$" %q %q > %q\n' \
+      '%s\t%s\t%s\n' "$PROJECT" "$AGENT_TYPE" "$_spawn_rec"
+  fi
   # Drop inherited same-type session-identity vars before exec'ing the CLI (#294).
   if [ -n "$SPAWN_UNSET_VARS" ]; then
     printf 'unset %s\n' "$SPAWN_UNSET_VARS"
diff --git a/tests/test_despawn.bats b/tests/test_despawn.bats
index 5048cb23..88938d35 100644
--- a/tests/test_despawn.bats
+++ b/tests/test_despawn.bats
@@ -65,6 +65,32 @@ _read_at_for_body() {
       "SELECT read_at FROM messages WHERE body='$1' ORDER BY id DESC LIMIT 1;" )
 }
 
+@test "despawn: graceful OS-terminal member is terminated after releasing its live lock" {
+  bash "$SCRIPTS/join.sh" team alice claude-code "$PROJ" >/dev/null
+  bash "$SCRIPTS/join.sh" team leader claude-code "$PROJ" >/dev/null
+  setup_live_owner "$RUN" sess-m
+  printf 'sess-m\n' > "$RUN/actas.team__alice.session"
+  printf 'pid:999999\t%s\tclaude-code\n' "$PROJ" > "$RUN/spawn.team__alice"
+
+  export KILL_LOG="$TEST_SKILL_DIR/kill.log"
+  kill() { printf '%s\n' "$*" >> "$KILL_LOG"; }
+  export -f kill
+  export LOCK_TO_RELEASE="$RUN/actas.team__alice.session"
+  local stub_bin="$TEST_SKILL_DIR/stub-bin-graceful"
+  mkdir -p "$stub_bin"
+  cat > "$stub_bin/sleep" <<'STUB'
+#!/usr/bin/env bash
+rm -f "$LOCK_TO_RELEASE"
+STUB
+  chmod +x "$stub_bin/sleep"
+
+  run env PATH="$stub_bin:$PATH" bash "$SCRIPTS/despawn.sh" team leader alice --timeout 2
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"status=ok"* ]]
+  grep -q -- '999999' "$KILL_LOG"
+  [ ! -f "$RUN/spawn.team__alice" ]
+}
+
 @test "despawn: graceful — ctrl:despawn control row is marked read (does not linger as unread)" {
   bash "$SCRIPTS/join.sh" team alice claude-code "$PROJ" >/dev/null
   bash "$SCRIPTS/join.sh" team leader claude-code "$PROJ" >/dev/null
@@ -103,6 +129,46 @@ _read_at_for_body() {
   [[ "$output" != *alice* ]]                        # registration dropped
 }
 
+@test "despawn --force: kills recorded OS-terminal PID and drops registration" {
+  bash "$SCRIPTS/join.sh" team alice claude-code "$PROJ" >/dev/null
+  printf 'pid:999999\t%s\tclaude-code\n' "$PROJ" > "$RUN/spawn.team__alice"
+  export KILL_LOG="$TEST_SKILL_DIR/kill.log"
+  kill() { printf '%s\n' "$*" >> "$KILL_LOG"; }
+  export -f kill
+
+  run bash "$SCRIPTS/despawn.sh" team leader alice --force
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"status=forced"* ]]
+  grep -q -- '999999' "$KILL_LOG"
+  [ ! -f "$RUN/spawn.team__alice" ]
+  run bash "$SCRIPTS/identities.sh" "$PROJ" claude-code
+  [[ "$output" != *alice* ]]
+}
+
+@test "despawn --force: terminates OS-terminal descendants before the boot PID" {
+  bash "$SCRIPTS/join.sh" team alice claude-code "$PROJ" >/dev/null
+  printf 'pid:999999\t%s\tclaude-code\n' "$PROJ" > "$RUN/spawn.team__alice"
+  export KILL_LOG="$TEST_SKILL_DIR/kill.log"
+  kill() { printf '%s\n' "$*" >> "$KILL_LOG"; }
+  export -f kill
+  local stub_bin="$TEST_SKILL_DIR/stub-bin-pgrep"
+  mkdir -p "$stub_bin"
+  cat > "$stub_bin/pgrep" <<'STUB'
+#!/usr/bin/env bash
+[ "${2:-}" = "999999" ] && printf '999998\n'
+STUB
+  chmod +x "$stub_bin/pgrep"
+
+  run env PATH="$stub_bin:$PATH" bash "$SCRIPTS/despawn.sh" team leader alice --force
+  [ "$status" -eq 0 ]
+  local calls=() call
+  while IFS= read -r call; do
+    calls+=("$call")
+  done < "$KILL_LOG"
+  [ "${calls[0]}" = "999998" ]
+  [ "${calls[1]}" = "999999" ]
+}
+
 @test "despawn --force: errors when there is no placement record" {
   bash "$SCRIPTS/join.sh" team alice claude-code "$PROJ" >/dev/null
   run bash "$SCRIPTS/despawn.sh" team leader alice --force
@@ -148,6 +214,21 @@ _read_at_for_body() {
   kill "$wpid" 2>/dev/null || true; wait "$wpid" 2>/dev/null || true
 }
 
+@test "despawn: graceful OS-terminal member without a live lock is terminated and de-registered" {
+  bash "$SCRIPTS/join.sh" team alice codex "$PROJ" >/dev/null
+  printf 'pid:999999\t%s\tcodex\n' "$PROJ" > "$RUN/spawn.team__alice"
+  export KILL_LOG="$TEST_SKILL_DIR/kill.log"
+  kill() { printf '%s\n' "$*" >> "$KILL_LOG"; }
+  export -f kill
+
+  run bash "$SCRIPTS/despawn.sh" team leader alice
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"status=ok"* ]]
+  grep -q -- '999999' "$KILL_LOG"
+  run bash "$SCRIPTS/identities.sh" "$PROJ" codex
+  [[ "$output" != *alice* ]]
+}
+
 @test "despawn: graceful no-op when the member holds no live lock (e.g. codex)" {
   bash "$SCRIPTS/join.sh" team alice codex "$PROJ" >/dev/null
   run bash "$SCRIPTS/despawn.sh" team leader alice
diff --git a/tests/test_spawn.bats b/tests/test_spawn.bats
index 48565edb..beb3be67 100644
--- a/tests/test_spawn.bats
+++ b/tests/test_spawn.bats
@@ -139,6 +139,25 @@ teardown() {
 
 # --- happy path / launch command ---
 
+@test "spawn: OS-terminal boot records its PID for despawn" {
+  cat > "$STUB_BIN/run-boot.sh" <<'STUB'
+#!/usr/bin/env bash
+printf 'exit\n' | "$1"
+STUB
+  chmod +x "$STUB_BIN/run-boot.sh"
+  export AGMSG_TERMINAL="$STUB_BIN/run-boot.sh {cmd}"
+
+  bash "$SCRIPTS/join.sh" myteam existing claude-code "$PROJ"
+  run bash "$SCRIPTS/spawn.sh" claude-code alice --project "$PROJ" --no-wait
+  [ "$status" -eq 0 ]
+
+  local record="$TEST_SKILL_DIR/run/spawn.myteam__alice"
+  [ -f "$record" ]
+  run cat "$record"
+  [ "$status" -eq 0 ]
+  [[ "$output" =~ ^pid:[0-9]+$'\t'"$PROJ"$'\t'claude-code$ ]]
+}
+
 @test "spawn: pre-joins the name and launches the CLI with the actas prompt" {
   bash "$SCRIPTS/join.sh" myteam existing claude-code "$PROJ"
   run bash "$SCRIPTS/spawn.sh" claude-code alice --project "$PROJ" --no-wait
@@ -867,6 +886,8 @@ EOF
   [[ "$output" == *"actas"* ]]
   [[ "$output" == *"alice"* ]]
   # No task appended → no newline-join → boot prompt unchanged.
+  run grep 'actas' "$boot"
+  [ "$status" -eq 0 ]
   [[ "$output" != *'\n'* ]]
 }