diff --git a/scripts/debug_trace_bench.md b/scripts/debug_trace_bench.md
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+++ b/scripts/debug_trace_bench.md
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+# debug_trace benchmark script (minimal path)
+
+This script provides a lightweight way to measure `debug_trace` performance over time with varying block transaction counts.
+
+Script: `scripts/debug_trace_bench.sh`
+
+## What it does
+
+1. Scans recent blocks (`eth_getBlockByNumber`) and picks candidate blocks by tx-count bins.
+2. Repeatedly runs:
+   - `debug_traceBlockByNumber`, or
+   - `debug_traceBlockByHash`
+3. Writes one CSV row per trace request, including:
+   - timestamp
+   - selected bin
+   - block height/hash
+   - tx count
+   - latency
+   - response size
+   - success/error details
+
+## Requirements
+
+- `curl`
+- `jq`
+
+## Examples
+
+Quick test (vary tx-density and run fixed request count):
+
+```bash
+./scripts/debug_trace_bench.sh \
+  --rpc-url http://127.0.0.1:8545 \
+  --bins "1-25,26-100,101-1000000" \
+  --samples-per-bin 1 \
+  --scan-back 2000 \
+  --iterations 120 \
+  --output ./trace_quick.csv
+```
+
+Long soak (degradation check over time):
+
+```bash
+./scripts/debug_trace_bench.sh \
+  --rpc-url http://127.0.0.1:8545 \
+  --bins "1-25,26-100,101-1000000" \
+  --samples-per-bin 2 \
+  --scan-back 10000 \
+  --duration-sec 3600 \
+  --sleep-ms 250 \
+  --output ./trace_soak.csv
+```
+
+Scan-only (inspect candidate blocks without tracing):
+
+```bash
+./scripts/debug_trace_bench.sh --scan-only --scan-back 5000
+```
+
+## Suggested workflow
+
+1. Start benchmark load generation (optional) to shape block tx counts:
+   - `scripts/benchmark.sh` with desired `BENCHMARK_TXS_PER_BATCH`.
+2. Run this script for one or more phases (different bins / durations).
+3. Compare `latency_sec` by:
+   - `target_bin` (tx density impact)
+   - timestamp progression (time-based degradation)
diff --git a/scripts/debug_trace_bench.sh b/scripts/debug_trace_bench.sh
new file mode 100644
index 0000000000..9c64d83bd3
--- /dev/null
+++ b/scripts/debug_trace_bench.sh
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+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+  cat <<'EOF'
+debug_trace benchmark/soak runner (minimal path)
+
+Discovers blocks with varying transaction counts, then repeatedly calls
+debug_trace and writes per-request CSV metrics.
+
+Requirements:
+  - curl
+  - jq
+
+Usage:
+  ./scripts/debug_trace_bench.sh [options]
+
+Core options:
+  --rpc-url URL              JSON-RPC endpoint (default: http://127.0.0.1:8545)
+  --bins SPEC                Tx-count bins, comma-separated min-max ranges
+                             (default: 1-10,11-50,51-200,201-1000000)
+  --samples-per-bin N        Number of distinct blocks to keep per bin (default: 1)
+  --scan-back N              Scan latest..latest-N blocks to find bin matches (default: 500)
+  --trace-by MODE            number|hash (default: number)
+  --tracer NAME              Tracer name (default: callTracer)
+  --trace-timeout DUR        Trace timeout string (e.g. 30s). Empty = omit field.
+
+Run length:
+  --iterations N             Total trace requests to run (default: 200)
+  --duration-sec N           Run for N seconds instead of fixed iterations
+  --sleep-ms N               Sleep between requests (default: 0)
+
+Output:
+  --output FILE              CSV output path
+                             (default: ./debug_trace_bench_<utc timestamp>.csv)
+  --scan-only                Only discover/print candidate blocks, do not trace
+
+Other:
+  -h, --help                Show this help
+
+Examples:
+  # Quick run: 3 bins, 1 block per bin, 90 total trace calls
+  ./scripts/debug_trace_bench.sh \
+    --bins "1-25,26-100,101-1000000" \
+    --samples-per-bin 1 \
+    --iterations 90 \
+    --output ./trace_quick.csv
+
+  # 30-minute soak with 250ms between calls
+  ./scripts/debug_trace_bench.sh \
+    --duration-sec 1800 \
+    --sleep-ms 250 \
+    --output ./trace_soak.csv
+EOF
+}
+
+require_binary() {
+  local bin="$1"
+  if ! command -v "$bin" >/dev/null 2>&1; then
+    echo "missing required binary: $bin" >&2
+    exit 1
+  fi
+}
+
+csv_escape() {
+  local s="$1"
+  s="${s//\"/\"\"}"
+  printf '"%s"' "$s"
+}
+
+to_hex() {
+  local n="$1"
+  printf "0x%x" "$n"
+}
+
+sleep_ms() {
+  local ms="$1"
+  if (( ms <= 0 )); then
+    return
+  fi
+  local sec=$((ms / 1000))
+  local rem=$((ms % 1000))
+  sleep "$(printf "%d.%03d" "$sec" "$rem")"
+}
+
+rpc_payload() {
+  local method="$1"
+  local params_json="$2"
+  jq -cn --arg method "$method" --argjson params "$params_json" \
+    '{"jsonrpc":"2.0","id":1,"method":$method,"params":$params}'
+}
+
+rpc_call_body() {
+  local method="$1"
+  local params_json="$2"
+  local payload
+  payload="$(rpc_payload "$method" "$params_json")"
+  curl -sS --max-time "$HTTP_TIMEOUT_SEC" \
+    -H "Content-Type: application/json" \
+    --data "$payload" \
+    "$RPC_URL"
+}
+
+rpc_call_timed_to_file() {
+  local method="$1"
+  local params_json="$2"
+  local body_file="$3"
+  local payload
+  payload="$(rpc_payload "$method" "$params_json")"
+  curl -sS --max-time "$HTTP_TIMEOUT_SEC" \
+    -o "$body_file" \
+    -w "%{http_code} %{time_total} %{size_download}" \
+    -H "Content-Type: application/json" \
+    --data "$payload" \
+    "$RPC_URL"
+}
+
+all_bins_filled() {
+  local i
+  for i in "${!BIN_LABELS[@]}"; do
+    if (( BIN_COUNTS[i] < SAMPLES_PER_BIN )); then
+      return 1
+    fi
+  done
+  return 0
+}
+
+print_candidates() {
+  echo "Selected candidate blocks:"
+  echo "  bin, height, tx_count, hash"
+  local i
+  for i in "${!TARGET_HEIGHTS[@]}"; do
+    echo "  ${TARGET_LABELS[i]}, ${TARGET_HEIGHTS[i]}, ${TARGET_TX_COUNTS[i]}, ${TARGET_HASHES[i]}"
+  done
+}
+
+validate_positive_int() {
+  local name="$1"
+  local val="$2"
+  if ! [[ "$val" =~ ^[0-9]+$ ]]; then
+    echo "$name must be a non-negative integer, got: $val" >&2
+    exit 1
+  fi
+}
+
+RPC_URL="http://127.0.0.1:8545"
+BINS="1-10,11-50,51-200,201-1000000"
+SAMPLES_PER_BIN=1
+SCAN_BACK=500
+TRACE_BY="number"
+TRACER="callTracer"
+TRACE_TIMEOUT=""
+ITERATIONS=200
+DURATION_SEC=0
+SLEEP_MS=0
+HTTP_TIMEOUT_SEC=120
+SCAN_ONLY=false
+OUTPUT_CSV="./debug_trace_bench_$(date -u +%Y%m%dT%H%M%SZ).csv"
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --rpc-url)
+      RPC_URL="${2:-}"; shift 2 ;;
+    --bins)
+      BINS="${2:-}"; shift 2 ;;
+    --samples-per-bin)
+      SAMPLES_PER_BIN="${2:-}"; shift 2 ;;
+    --scan-back)
+      SCAN_BACK="${2:-}"; shift 2 ;;
+    --trace-by)
+      TRACE_BY="${2:-}"; shift 2 ;;
+    --tracer)
+      TRACER="${2:-}"; shift 2 ;;
+    --trace-timeout)
+      TRACE_TIMEOUT="${2:-}"; shift 2 ;;
+    --iterations)
+      ITERATIONS="${2:-}"; shift 2 ;;
+    --duration-sec)
+      DURATION_SEC="${2:-}"; shift 2 ;;
+    --sleep-ms)
+      SLEEP_MS="${2:-}"; shift 2 ;;
+    --output)
+      OUTPUT_CSV="${2:-}"; shift 2 ;;
+    --scan-only)
+      SCAN_ONLY=true; shift 1 ;;
+    -h|--help)
+      usage; exit 0 ;;
+    *)
+      echo "unknown argument: $1" >&2
+      usage
+      exit 1 ;;
+  esac
+done
+
+require_binary curl
+require_binary jq
+
+validate_positive_int "samples-per-bin" "$SAMPLES_PER_BIN"
+validate_positive_int "scan-back" "$SCAN_BACK"
+validate_positive_int "iterations" "$ITERATIONS"
+validate_positive_int "duration-sec" "$DURATION_SEC"
+validate_positive_int "sleep-ms" "$SLEEP_MS"
+
+if [[ "$TRACE_BY" != "number" && "$TRACE_BY" != "hash" ]]; then
+  echo "--trace-by must be 'number' or 'hash', got: $TRACE_BY" >&2
+  exit 1
+fi
+
+if (( DURATION_SEC == 0 && ITERATIONS == 0 )); then
+  echo "either --iterations or --duration-sec must be > 0" >&2
+  exit 1
+fi
+
+IFS=',' read -r -a RAW_BINS <<< "$BINS"
+if (( ${#RAW_BINS[@]} == 0 )); then
+  echo "no bins parsed from --bins: $BINS" >&2
+  exit 1
+fi
+
+BIN_LABELS=()
+BIN_MINS=()
+BIN_MAXS=()
+BIN_COUNTS=()
+for raw in "${RAW_BINS[@]}"; do
+  spec="${raw//[[:space:]]/}"
+  if [[ "$spec" =~ ^([0-9]+)-([0-9]+)$ ]]; then
+    mn="${BASH_REMATCH[1]}"
+    mx="${BASH_REMATCH[2]}"
+    if (( mn > mx )); then
+      echo "invalid bin '$spec': min > max" >&2
+      exit 1
+    fi
+    BIN_LABELS+=("$spec")
+    BIN_MINS+=("$mn")
+    BIN_MAXS+=("$mx")
+    BIN_COUNTS+=(0)
+  else
+    echo "invalid bin '$spec'. Expected format min-max (e.g. 11-50)." >&2
+    exit 1
+  fi
+done
+
+echo "Discovering candidate blocks on $RPC_URL ..." >&2
+latest_body="$(rpc_call_body "eth_blockNumber" "[]")"
+if jq -e '.error != null' >/dev/null 2>&1 <<<"$latest_body"; then
+  echo "eth_blockNumber returned error:" >&2
+  echo "$latest_body" >&2
+  exit 1
+fi
+
+latest_hex="$(jq -r '.result // empty' <<<"$latest_body")"
+if [[ -z "$latest_hex" || "$latest_hex" == "null" ]]; then
+  echo "eth_blockNumber returned empty result" >&2
+  exit 1
+fi
+
+latest_dec=$((16#${latest_hex#0x}))
+start_dec=$((latest_dec - SCAN_BACK))
+if (( start_dec < 0 )); then
+  start_dec=0
+fi
+
+TARGET_LABELS=()
+TARGET_HEIGHTS=()
+TARGET_HASHES=()
+TARGET_TX_COUNTS=()
+
+for (( h=latest_dec; h>=start_dec; h-- )); do
+  if all_bins_filled; then
+    break
+  fi
+
+  block_hex="$(to_hex "$h")"
+  params_json="$(jq -cn --arg block "$block_hex" '[$block, false]')"
+  block_body="$(rpc_call_body "eth_getBlockByNumber" "$params_json")"
+
+  if jq -e '.error != null' >/dev/null 2>&1 <<<"$block_body"; then
+    continue
+  fi
+
+  hash="$(jq -r '.result.hash // empty' <<<"$block_body")"
+  tx_count="$(jq -r 'if .result == null then -1 else (.result.transactions | length) end' <<<"$block_body")"
+
+  if [[ -z "$hash" || "$tx_count" == "-1" ]]; then
+    continue
+  fi
+
+  for i in "${!BIN_LABELS[@]}"; do
+    if (( BIN_COUNTS[i] >= SAMPLES_PER_BIN )); then
+      continue
+    fi
+    if (( tx_count >= BIN_MINS[i] && tx_count <= BIN_MAXS[i] )); then
+      TARGET_LABELS+=("${BIN_LABELS[i]}")
+      TARGET_HEIGHTS+=("$h")
+      TARGET_HASHES+=("$hash")
+      TARGET_TX_COUNTS+=("$tx_count")
+      BIN_COUNTS[i]=$((BIN_COUNTS[i] + 1))
+      echo "  selected bin=${BIN_LABELS[i]} height=$h txs=$tx_count hash=$hash" >&2
+      break
+    fi
+  done
+done
+
+target_count="${#TARGET_HEIGHTS[@]}"
+if (( target_count == 0 )); then
+  echo "no candidate blocks found in scanned range" >&2
+  exit 1
+fi
+
+for i in "${!BIN_LABELS[@]}"; do
+  if (( BIN_COUNTS[i] < SAMPLES_PER_BIN )); then
+    echo "warning: bin ${BIN_LABELS[i]} only found ${BIN_COUNTS[i]} blocks (wanted $SAMPLES_PER_BIN)" >&2
+  fi
+done
+
+print_candidates
+
+if [[ "$SCAN_ONLY" == "true" ]]; then
+  exit 0
+fi
+
+mkdir -p "$(dirname "$OUTPUT_CSV")"
+cat > "$OUTPUT_CSV" <<'EOF'
+timestamp_utc,request_index,target_bin,block_height,block_hash,tx_count,trace_method,tracer,http_code,latency_sec,response_bytes,success,error_code,error_message
+EOF
+
+TRACE_METHOD="debug_traceBlockByNumber"
+if [[ "$TRACE_BY" == "hash" ]]; then
+  TRACE_METHOD="debug_traceBlockByHash"
+fi
+
+if [[ -n "$TRACE_TIMEOUT" ]]; then
+  TRACE_CONFIG_JSON="$(jq -cn --arg tracer "$TRACER" --arg timeout "$TRACE_TIMEOUT" '{tracer:$tracer, timeout:$timeout}')"
+else
+  TRACE_CONFIG_JSON="$(jq -cn --arg tracer "$TRACER" '{tracer:$tracer}')"
+fi
+
+echo "Running trace benchmark..." >&2
+echo "  method=$TRACE_METHOD tracer=$TRACER trace_by=$TRACE_BY" >&2
+echo "  output=$OUTPUT_CSV" >&2
+
+request_idx=0
+success_count=0
+failure_count=0
+
+end_at=0
+if (( DURATION_SEC > 0 )); then
+  end_at=$((SECONDS + DURATION_SEC))
+fi
+
+while :; do
+  if (( DURATION_SEC > 0 )); then
+    if (( SECONDS >= end_at )); then
+      break
+    fi
+  else
+    if (( request_idx >= ITERATIONS )); then
+      break
+    fi
+  fi
+
+  target_i=$((request_idx % target_count))
+  req_num=$((request_idx + 1))
+
+  bin_label="${TARGET_LABELS[target_i]}"
+  height_dec="${TARGET_HEIGHTS[target_i]}"
+  block_hash="${TARGET_HASHES[target_i]}"
+  tx_count="${TARGET_TX_COUNTS[target_i]}"
+
+  block_param="$(to_hex "$height_dec")"
+  if [[ "$TRACE_BY" == "hash" ]]; then
+    block_param="$block_hash"
+  fi
+
+  params_json="$(jq -cn --arg block "$block_param" --argjson cfg "$TRACE_CONFIG_JSON" '[$block, $cfg]')"
+  body_file="$(mktemp)"
+
+  set +e
+  metrics="$(rpc_call_timed_to_file "$TRACE_METHOD" "$params_json" "$body_file")"
+  curl_rc=$?
+  set -e
+
+  http_code="000"
+  latency="0"
+  response_bytes="0"
+  success="false"
+  error_code=""
+  error_message=""
+
+  if (( curl_rc != 0 )); then
+    error_message="curl_failed_rc_${curl_rc}"
+    failure_count=$((failure_count + 1))
+  else
+    read -r http_code latency response_bytes <<<"$metrics"
+
+    if ! jq -e . >/dev/null 2>&1 "$body_file"; then
+      error_message="invalid_json_response"
+      failure_count=$((failure_count + 1))
+    elif jq -e '.error != null' >/dev/null 2>&1 "$body_file"; then
+      success="false"
+      error_code="$(jq -r '.error.code // ""' "$body_file")"
+      error_message="$(jq -r '.error.message // ""' "$body_file")"
+      failure_count=$((failure_count + 1))
+    else
+      success="true"
+      success_count=$((success_count + 1))
+    fi
+  fi
+
+  ts="$(date -u +"%Y-%m-%dT%H:%M:%SZ")"
+  {
+    csv_escape "$ts"; printf ","
+    csv_escape "$req_num"; printf ","
+    csv_escape "$bin_label"; printf ","
+    csv_escape "$height_dec"; printf ","
+    csv_escape "$block_hash"; printf ","
+    csv_escape "$tx_count"; printf ","
+    csv_escape "$TRACE_METHOD"; printf ","
+    csv_escape "$TRACER"; printf ","
+    csv_escape "$http_code"; printf ","
+    csv_escape "$latency"; printf ","
+    csv_escape "$response_bytes"; printf ","
+    csv_escape "$success"; printf ","
+    csv_escape "$error_code"; printf ","
+    csv_escape "$error_message"; printf "\n"
+  } >> "$OUTPUT_CSV"
+
+  rm -f "$body_file"
+
+  request_idx=$req_num
+  if (( request_idx % 25 == 0 )); then
+    echo "  progress: requests=$request_idx success=$success_count failure=$failure_count" >&2
+  fi
+
+  sleep_ms "$SLEEP_MS"
+done
+
+echo "Done." >&2
+echo "  requests=$request_idx success=$success_count failure=$failure_count" >&2
+echo "  csv=$OUTPUT_CSV" >&2