diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c086af..2699982 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/), and this project adheres to [Semantic Versioning](https://semver.org/).
 
+## [0.61.0] - 2026-06-12
+
+LLM 性能監査（#121）P2 の第 1 弾（#111）。tmux-hooks のハードブロックをリマインダーに降格した。
+
+### Changed
+- **tmux-hooks のハードブロックを非ブロックのリマインダーに降格（#111）**: TMUX 外での dev サーバー起動（`npm run dev` 等）を exit 2 でブロックしていた挙動を撤廃。現行 Claude Code はネイティブの background 実行（`run_in_background`）とログ取得を備えており、ブロックはむしろネイティブ機能の利用を妨害していた。新挙動: (1) `run_in_background=true` は即許可（出力なし）、(2) TMUX 外の foreground dev サーバーは exit 0 + stderr 1 行のリマインダー（run_in_background を第一候補、永続セッションが必要なら tmux を代替として提示）、(3) npm test / cargo build / docker 等への「Consider running in tmux」定常 advisory は削除（高頻度コマンドへの情報量ゼロのノイズ）
+
 ## [0.60.0] - 2026-06-12
 
 LLM 性能監査（#121）P1 の最終弾（#110）。pre-compact-commit を opt-in 化し、履歴を汚さない stash 方式に書き換えた。
diff --git a/README.en.md b/README.en.md
index 3990f9e..13350dd 100644
--- a/README.en.md
+++ b/README.en.md
@@ -190,7 +190,7 @@ Hooks are automated safety checks that run automatically when Claude Code execut
 |---|---|
 | **Safety Net** | Blocks destructive git/filesystem commands (`git reset --hard`, `rm -rf`, `git push --force`, etc.) before execution |
 | **Auto Update** | Checks for starter kit updates on session start and applies them in the background |
-| Tmux Reminder | Suggests tmux for long-running commands |
+| Tmux Reminder | Suggests run_in_background for foreground dev servers (non-blocking) |
 | Git Push Review | Pauses before git push for code review |
 | Doc Blocker | Prevents creation of unnecessary .md/.txt files |
 | Prettier Auto-format | Formats JS/TS files after edits |
diff --git a/README.md b/README.md
index 2f14261..0ea374a 100644
--- a/README.md
+++ b/README.md
@@ -470,7 +470,7 @@ URL・公式ドキュメント・ブログ・ニュース・OSS ページを読
 |---|---|
 | **Safety Net** | **破壊的な git/ファイルシステムコマンド（`git reset --hard`、`rm -rf` 等）を実行前にブロック** |
 | **自動アップデート** | **セッション開始時にスターターキットの最新版を自動で適用** |
-| Tmux リマインダー | 長時間コマンドに tmux の使用を提案 |
+| Tmux リマインダー | foreground の dev サーバーに run_in_background を提案（非ブロック） |
 | Git Push レビュー | コードを共有する前に確認を促す |
 | Doc ブロッカー | 不要なドキュメントファイルの作成を防止 |
 | Prettier 自動フォーマット | JS/TS ファイルを自動で見た目を整える |
diff --git a/docs/wizard-config-mapping.en.md b/docs/wizard-config-mapping.en.md
index 0ccffc0..bc216bd 100644
--- a/docs/wizard-config-mapping.en.md
+++ b/docs/wizard-config-mapping.en.md
@@ -58,7 +58,7 @@ These flags are used to merge the corresponding `features/*/hooks.json` fragment
 | `ENABLE_SAFETY_NET` | Safety Net | Block destructive commands | Yes |
 | `ENABLE_AUTO_UPDATE` | Auto Update | Check for starter kit updates on session start | Yes |
 | `ENABLE_WEB_CONTENT_UPDATE` | Web Content Update | Check web extraction skill dependency updates | Yes |
-| `ENABLE_TMUX_HOOKS` | Tmux Reminder | Encourage tmux for long-running work | Yes |
+| `ENABLE_TMUX_HOOKS` | Tmux Reminder | Suggest run_in_background for foreground dev servers (non-blocking) | Yes |
 | `ENABLE_GIT_PUSH_REVIEW` | Git Push Review | Pause before push and open a diff | Yes |
 | `ENABLE_DOC_BLOCKER` | Doc Blocker | Prevent unnecessary `.md` / `.txt` files | Yes |
 | `ENABLE_PRETTIER_HOOKS` | Prettier Auto-format | Format JS / TS edits | Yes |
diff --git a/docs/wizard-config-mapping.md b/docs/wizard-config-mapping.md
index 8723df8..6dd5dbc 100644
--- a/docs/wizard-config-mapping.md
+++ b/docs/wizard-config-mapping.md
@@ -58,7 +58,7 @@
 | `ENABLE_SAFETY_NET` | Safety Net | 危険なコマンドの遮断 | はい |
 | `ENABLE_AUTO_UPDATE` | Auto Update | セッション開始時の更新確認 | はい |
 | `ENABLE_WEB_CONTENT_UPDATE` | Web Content Update | Web 取得スキル依存の更新確認 | はい |
-| `ENABLE_TMUX_HOOKS` | Tmux Reminder | 長時間処理を tmux に誘導 | はい |
+| `ENABLE_TMUX_HOOKS` | Tmux Reminder | foreground の dev サーバーに run_in_background を提案（非ブロック） | はい |
 | `ENABLE_GIT_PUSH_REVIEW` | Git Push Review | push 前に差分確認 | はい |
 | `ENABLE_DOC_BLOCKER` | Doc Blocker | 不要な `.md` / `.txt` 作成を抑制 | はい |
 | `ENABLE_PRETTIER_HOOKS` | Prettier Auto-format | JS / TS 編集後の整形 | はい |
diff --git a/features/tmux-hooks/feature.json b/features/tmux-hooks/feature.json
index 98d596b..b9b7abb 100644
--- a/features/tmux-hooks/feature.json
+++ b/features/tmux-hooks/feature.json
@@ -1,10 +1,14 @@
 {
 	"name": "tmux-hooks",
 	"displayName": "Tmux Reminder",
-	"description": "Block dev servers outside tmux and suggest tmux for long-running commands",
+	"description": "Non-blocking reminder: suggest run_in_background (or tmux) for foreground dev servers",
 	"category": "hook",
 	"default": true,
-	"profiles": { "minimal": false, "standard": true, "full": true },
+	"profiles": {
+		"minimal": false,
+		"standard": true,
+		"full": true
+	},
 	"dependencies": [],
 	"conflicts": []
 }
diff --git a/features/tmux-hooks/scripts/check-bash.sh b/features/tmux-hooks/scripts/check-bash.sh
index dcd6e48..fc0393a 100755
--- a/features/tmux-hooks/scripts/check-bash.sh
+++ b/features/tmux-hooks/scripts/check-bash.sh
@@ -3,17 +3,18 @@ set -euo pipefail
 
 input="$(cat)"
 cmd="$(printf '%s' "$input" | jq -r '.tool_input.command // ""')"
+run_in_background="$(printf '%s' "$input" | jq -r '.tool_input.run_in_background // false')"
 
+# Native background execution manages the process and its logs — nothing to add.
+if [[ "$run_in_background" == "true" ]]; then
+  exit 0
+fi
+
+# Foreground dev server outside tmux: non-blocking reminder only.
 if printf '%s' "$cmd" | grep -qE '(npm run dev|pnpm( run)? dev|yarn dev|bun run dev)' \
   && [[ -z "${TMUX:-}" ]] \
   && ! printf '%s' "$cmd" | grep -qE 'tmux[[:space:]]+(new-session|new|send-keys)'; then
-  echo '[Hook] BLOCKED: Dev server must run in tmux for log access' >&2
-  echo '[Hook] Use: tmux new-session -d -s dev "npm run dev"' >&2
-  echo '[Hook] Then: tmux attach -t dev' >&2
-  exit 2
+  echo '[Hook] Reminder: prefer run_in_background for dev servers (or tmux new-session for a persistent session)' >&2
 fi
 
-if printf '%s' "$cmd" | grep -qE '(npm (install|test)|pnpm (install|test)|yarn (install|test)|bun (install|test)|cargo build|make|docker|pytest|vitest|playwright)' \
-  && [[ -z "${TMUX:-}" ]]; then
-  echo '[Hook] Consider running in tmux for session persistence' >&2
-fi
+exit 0
diff --git a/i18n/en/strings.sh b/i18n/en/strings.sh
index 69bf3d1..2602e79 100644
--- a/i18n/en/strings.sh
+++ b/i18n/en/strings.sh
@@ -84,7 +84,7 @@ STR_HOOKS_TITLE="Select hooks to enable (enter numbers separated by spaces):"
 STR_HOOKS_SAFETY_NET="Safety Net - Block destructive git/filesystem commands (cc-safety-net)"
 STR_HOOKS_AUTO_UPDATE="Auto Update - Automatically update starter kit on session start"
 STR_HOOKS_WEB_CONTENT_UPDATE="Web Content Update - Auto-update web-content-extraction skill deps on session start (opt-in)"
-STR_HOOKS_TMUX="Tmux Reminder - Suggest tmux for long-running commands"
+STR_HOOKS_TMUX="Tmux Reminder - Suggest run_in_background for foreground dev servers (non-blocking)"
 STR_HOOKS_GIT_PUSH="Git Push Review - Pause before git push for review"
 STR_HOOKS_DOC_BLOCK="Doc Blocker - Block creation of random .md/.txt files"
 STR_HOOKS_PRETTIER="Prettier Auto-format - Format JS/TS files after edits"
diff --git a/i18n/ja/strings.sh b/i18n/ja/strings.sh
index 8b0e420..56e296c 100644
--- a/i18n/ja/strings.sh
+++ b/i18n/ja/strings.sh
@@ -82,7 +82,7 @@ STR_HOOKS_TITLE="有効にするフックを選択してください（番号を
 STR_HOOKS_SAFETY_NET="Safety Net - 破壊的な git/ファイルシステムコマンドをブロック (cc-safety-net)"
 STR_HOOKS_AUTO_UPDATE="自動アップデート - セッション開始時にスターターキットを自動更新"
 STR_HOOKS_WEB_CONTENT_UPDATE="Web取得スキル更新 - セッション開始時に web-content-extraction の依存を自動更新（opt-in）"
-STR_HOOKS_TMUX="Tmux リマインダー - 長時間コマンドに tmux を提案"
+STR_HOOKS_TMUX="Tmux リマインダー - foreground の dev サーバーに run_in_background を提案（非ブロック）"
 STR_HOOKS_GIT_PUSH="Git Push レビュー - push 前に一時停止してレビュー"
 STR_HOOKS_DOC_BLOCK="ドキュメントブロッカー - 不要な .md/.txt ファイルの作成を防止"
 STR_HOOKS_PRETTIER="Prettier 自動フォーマット - JS/TS ファイルを編集後にフォーマット"
diff --git a/tests/unit/test-hook-fixtures.sh b/tests/unit/test-hook-fixtures.sh
index 99a6768..6534649 100644
--- a/tests/unit/test-hook-fixtures.sh
+++ b/tests/unit/test-hook-fixtures.sh
@@ -105,13 +105,13 @@ bash "$PROJECT_DIR/features/git-push-review/scripts/remind.sh" <"$_pre_push_fixt
 bash "$PROJECT_DIR/features/feature-recommendation/scripts/check-pending.sh" <"$_hook_fixture_dir/sessionstart-startup.json" >/dev/null 2>/dev/null || _script_smoke_ok=false
 
 _tmux_rc=0
-bash "$PROJECT_DIR/features/tmux-hooks/scripts/check-bash.sh" <"$_pre_dev_fixture" >/dev/null 2>"$_hook_tmp/tmux.err" || _tmux_rc=$?
+env -u TMUX bash "$PROJECT_DIR/features/tmux-hooks/scripts/check-bash.sh" <"$_pre_dev_fixture" >/dev/null 2>"$_hook_tmp/tmux.err" || _tmux_rc=$?
 
 if [[ "$_script_smoke_ok" == "true" ]] \
   && assert_matches "console\\.log found" "$(cat "$_hook_tmp/console.err")" \
   && assert_matches "Reminder: review your staged changes" "$(cat "$_hook_tmp/push.err")" \
-  && [[ "$_tmux_rc" -eq 2 ]] \
-  && assert_matches "Dev server must run in tmux" "$(cat "$_hook_tmp/tmux.err")"; then
+  && [[ "$_tmux_rc" -eq 0 ]] \
+  && assert_matches "prefer run_in_background" "$(cat "$_hook_tmp/tmux.err")"; then
   pass "hook-fixtures: distributed hook scripts consume real-schema fixtures"
 else
   fail "hook-fixtures: distributed hook scripts should consume real-schema fixtures"
diff --git a/tests/unit/test-runtime-hooks.sh b/tests/unit/test-runtime-hooks.sh
index 4ad82c1..41f6f3a 100644
--- a/tests/unit/test-runtime-hooks.sh
+++ b/tests/unit/test-runtime-hooks.sh
@@ -75,3 +75,62 @@
     fail "$test_name"
   fi
 }
+
+
+{
+  test_name="tmux-hooks: run_in_background dev server passes without any output"
+  _th_tmp="$(mktemp -d)"
+  _SETUP_TMP_FILES+=("$_th_tmp")
+  _th_rc=0
+  printf '{"tool_name":"Bash","tool_input":{"command":"%s","run_in_background":true}}' "npm run dev" \
+    | env -u TMUX bash "$PROJECT_DIR/features/tmux-hooks/scripts/check-bash.sh" >/dev/null 2>"$_th_tmp/bg.err" || _th_rc=$?
+  if [[ "$_th_rc" -eq 0 ]] && [[ ! -s "$_th_tmp/bg.err" ]]; then
+    pass "$test_name"
+  else
+    fail "$test_name"
+  fi
+}
+
+{
+  test_name="tmux-hooks: foreground dev server is a non-blocking reminder (no exit 2)"
+  _th_tmp2="$(mktemp -d)"
+  _SETUP_TMP_FILES+=("$_th_tmp2")
+  _th_rc=0
+  printf '{"tool_name":"Bash","tool_input":{"command":"%s"}}' "npm run dev" \
+    | env -u TMUX bash "$PROJECT_DIR/features/tmux-hooks/scripts/check-bash.sh" >/dev/null 2>"$_th_tmp2/fg.err" || _th_rc=$?
+  if [[ "$_th_rc" -eq 0 ]] \
+    && grep -q "prefer run_in_background" "$_th_tmp2/fg.err" \
+    && ! grep -q "BLOCKED" "$_th_tmp2/fg.err"; then
+    pass "$test_name"
+  else
+    fail "$test_name"
+  fi
+}
+
+{
+  test_name="tmux-hooks: build/test commands no longer trigger advisory noise"
+  _th_tmp3="$(mktemp -d)"
+  _SETUP_TMP_FILES+=("$_th_tmp3")
+  _th_rc=0
+  printf '{"tool_name":"Bash","tool_input":{"command":"npm test"}}' \
+    | env -u TMUX bash "$PROJECT_DIR/features/tmux-hooks/scripts/check-bash.sh" >/dev/null 2>"$_th_tmp3/adv.err" || _th_rc=$?
+  if [[ "$_th_rc" -eq 0 ]] && [[ ! -s "$_th_tmp3/adv.err" ]]; then
+    pass "$test_name"
+  else
+    fail "$test_name"
+  fi
+}
+
+{
+  test_name="tmux-hooks: dev server inside tmux session stays silent"
+  _th_tmp4="$(mktemp -d)"
+  _SETUP_TMP_FILES+=("$_th_tmp4")
+  _th_rc=0
+  printf '{"tool_name":"Bash","tool_input":{"command":"npm run %s"}}' "dev" \
+    | env TMUX=fake-session bash "$PROJECT_DIR/features/tmux-hooks/scripts/check-bash.sh" >/dev/null 2>"$_th_tmp4/in-tmux.err" || _th_rc=$?
+  if [[ "$_th_rc" -eq 0 ]] && [[ ! -s "$_th_tmp4/in-tmux.err" ]]; then
+    pass "$test_name"
+  else
+    fail "$test_name"
+  fi
+}