diff --git a/scripts/common/adaptive_heartbeat.sh b/scripts/common/adaptive_heartbeat.sh
new file mode 100755
index 0000000..b5366be
--- /dev/null
+++ b/scripts/common/adaptive_heartbeat.sh
@@ -0,0 +1,104 @@
+#!/usr/bin/env bash
+# Lightweight heartbeat monitor for a long-running adaptive benchmark.
+set -uo pipefail
+
+if (( $# < 2 )); then
+  echo "Usage: $0 RUN_ROOT MAIN_TMUX [ENGINE_PORT] [SERVICE_NAME_PATTERN]" >&2
+  exit 2
+fi
+
+RUN_ROOT="$1"
+MAIN_TMUX="$2"
+ENGINE_PORT="${3:-}"
+SERVICE_NAME_PATTERN="${4:-}"
+INTERVAL_S="${HEARTBEAT_INTERVAL_S:-60}"
+LOG_FILE="${HEARTBEAT_LOG_FILE:-${RUN_ROOT}/heartbeat.log}"
+
+if ! [[ "$INTERVAL_S" =~ ^[1-9][0-9]*$ ]]; then
+  echo "HEARTBEAT_INTERVAL_S must be a positive integer" >&2
+  exit 2
+fi
+
+mkdir -p "$(dirname "$LOG_FILE")"
+
+line_count() {
+  local path="$1"
+  if [[ -f "$path" ]]; then
+    wc -l < "$path" | tr -d ' '
+  else
+    printf '0'
+  fi
+}
+
+gpu_summary() {
+  nvidia-smi \
+    --query-gpu=index,memory.used,utilization.gpu \
+    --format=csv,noheader,nounits 2>/dev/null | \
+    awk -F',' '
+      {
+        for (i = 1; i <= NF; i++) gsub(/^[[:space:]]+|[[:space:]]+$/, "", $i)
+        printf "%s%s:%sMiB/%s%%", (NR == 1 ? "" : ";"), $1, $2, $3
+      }
+      END { if (NR == 0) printf "unavailable" }
+    '
+}
+
+heartbeat_once() {
+  local timestamp tmux_state health_state container_names container_state
+  local points shapes last_line gpu
+
+  timestamp="$(date --iso-8601=seconds)"
+  if tmux has-session -t "$MAIN_TMUX" 2>/dev/null; then
+    tmux_state="up"
+  else
+    tmux_state="down"
+  fi
+
+  health_state="n/a"
+  if [[ -n "$ENGINE_PORT" ]]; then
+    if curl --fail --silent --max-time 5 \
+      "http://127.0.0.1:${ENGINE_PORT}/health" >/dev/null 2>&1; then
+      health_state="ok"
+    else
+      health_state="down"
+    fi
+  fi
+
+  container_names=""
+  if [[ -n "$SERVICE_NAME_PATTERN" ]]; then
+    container_names="$(
+      docker ps --filter "name=${SERVICE_NAME_PATTERN}" --format '{{.Names}}' 2>/dev/null | \
+        paste -sd, -
+    )"
+  fi
+  if [[ -n "$container_names" ]]; then
+    container_state="$container_names"
+  else
+    container_state="none"
+  fi
+
+  points="$(line_count "${RUN_ROOT}/adaptive_points.jsonl")"
+  shapes="$(line_count "${RUN_ROOT}/adaptive_shapes.jsonl")"
+  last_line="$(
+    tail -n 1 "${RUN_ROOT}/logs/orchestrator.log" 2>/dev/null | \
+      tr '\t\r\n' ' ' | cut -c1-320
+  )"
+  gpu="$(gpu_summary)"
+
+  printf '[%s] benchmark_tmux=%s health=%s service=%s points=%s shapes=%s gpu=%s last="%s"\n' \
+    "$timestamp" "$tmux_state" "$health_state" "$container_state" \
+    "$points" "$shapes" "$gpu" "$last_line" | tee -a "$LOG_FILE"
+
+  [[ "$tmux_state" == "up" ]]
+}
+
+printf '[%s] heartbeat_started interval_s=%s main_tmux=%s run_root=%s\n' \
+  "$(date --iso-8601=seconds)" "$INTERVAL_S" "$MAIN_TMUX" "$RUN_ROOT" | \
+  tee -a "$LOG_FILE"
+
+while heartbeat_once; do
+  sleep "$INTERVAL_S"
+done
+
+printf '[%s] heartbeat_stopped reason=benchmark_tmux_down\n' \
+  "$(date --iso-8601=seconds)" | tee -a "$LOG_FILE"