diff --git a/Cargo.toml b/Cargo.toml
index 4dd43f9e..dc28eb05 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -42,14 +42,14 @@ llvm-harness = []
 llvm-inkwell-legacy = ["dep:inkwell"]
 llvm = ["llvm-harness"]
 # (removed) Optional modular MIR builder feature
-cranelift-jit = [
-  "dep:cranelift-codegen",
-  "dep:cranelift-frontend",
-  "dep:cranelift-module",
-  "dep:cranelift-jit",
-  "dep:cranelift-object",
-  "dep:cranelift-native"
-]
+# cranelift-jit = [    # ARCHIVED: Moved to archive/jit-cranelift/ during Phase 15
+#   "dep:cranelift-codegen",
+#   "dep:cranelift-frontend",
+#   "dep:cranelift-module",
+#   "dep:cranelift-jit",
+#   "dep:cranelift-object",
+#   "dep:cranelift-native"
+# ]
 aot-plan-import = []
 
 [lib]
@@ -157,13 +157,13 @@ wasm-bindgen = "0.2"
 console_error_panic_hook = "0.1"
 js-sys = "0.3"
 
-# Cranelift JIT (optional; enabled via feature "cranelift-jit")
-cranelift-codegen = { version = "0.103", optional = true }
-cranelift-frontend = { version = "0.103", optional = true }
-cranelift-module = { version = "0.103", optional = true }
-cranelift-jit = { version = "0.103", optional = true }
-cranelift-object = { version = "0.103", optional = true }
-cranelift-native = { version = "0.103", optional = true }
+# Cranelift JIT (ARCHIVED: moved to archive/jit-cranelift/ during Phase 15)
+# cranelift-codegen = { version = "0.103", optional = true }
+# cranelift-frontend = { version = "0.103", optional = true }
+# cranelift-module = { version = "0.103", optional = true }
+# cranelift-jit = { version = "0.103", optional = true }
+# cranelift-object = { version = "0.103", optional = true }
+# cranelift-native = { version = "0.103", optional = true }
 
 # WASM backend dependencies (Phase 8) - optional for faster builds
 wabt = { version = "0.10", optional = true }
diff --git a/archive/jit-cranelift/ARCHIVE_NOTES.md b/archive/jit-cranelift/ARCHIVE_NOTES.md
new file mode 100644
index 00000000..e500c8b5
--- /dev/null
+++ b/archive/jit-cranelift/ARCHIVE_NOTES.md
@@ -0,0 +1,96 @@
+# JIT/Cranelift アーカイブ - Phase 15
+
+## 📅 アーカイブ日時
+2025-09-23 - Phase 15 セルフホスティング集中開発期間中
+
+## 🎯 アーカイブ理由
+
+### 現在の開発焦点
+- **Phase 15**: Nyashセルフホスティング（80k→20k行革命）
+- **開発対象**: PyVMとLLVMバックエンドのみ
+- **JIT/Cranelift**: 現在未使用、ビルドエラーや混乱の原因
+
+### 具体的な問題
+1. **ビルドエラー**: `cranelift-jit` フィーチャーでのビルド失敗
+2. **AI開発者の混乱**: JSON開発Claude Codeが誤ってJITルートを参照
+3. **リソース分散**: メンテナンスコストが高い
+4. **Phase 15集中**: PyVM/LLVM開発に集中したい
+
+## 📂 アーカイブ内容
+
+### 移動されたディレクトリ・ファイル
+```
+archive/jit-cranelift/
+├── src/
+│   ├── jit/                           # JIT実装コア（ABI、エンジン、ローワリング等）
+│   └── backend/cranelift/             # Craneliftバックエンド実装
+├── scripts/
+│   └── build_jit.sh                   # JITビルドスクリプト
+└── tools/
+    ├── jit_compare_smoke.sh           # JIT比較スモークテスト
+    └── smokes/
+        ├── jit_smoke.sh               # JITスモークテスト
+        └── smoke_vm_jit.sh             # VM-JIT比較テスト
+```
+
+### Cargo.toml変更
+- `cranelift-jit` フィーチャーをコメントアウト
+- JIT関連の依存関係を無効化
+
+## 🔄 復活手順（将来用）
+
+### 1. ファイル復元
+```bash
+# アーカイブから復元
+mv archive/jit-cranelift/src/jit src/
+mv archive/jit-cranelift/src/backend/cranelift src/backend/
+mv archive/jit-cranelift/scripts/build_jit.sh .
+mv archive/jit-cranelift/tools/* tools/
+```
+
+### 2. Cargo.toml復元
+```toml
+[features]
+cranelift-jit = ["dep:cranelift", "dep:cranelift-jit", "dep:cranelift-module"]
+
+[dependencies]
+cranelift = { version = "0.103", optional = true }
+cranelift-jit = { version = "0.103", optional = true }
+cranelift-module = { version = "0.103", optional = true }
+```
+
+### 3. ビルド確認
+```bash
+# JITビルドテスト
+cargo build --release --features cranelift-jit
+
+# スモークテスト実行
+./tools/jit_smoke.sh
+```
+
+### 4. 統合テスト
+- PyVM vs JIT性能比較
+- LLVM vs JIT出力比較
+- 全バックエンド統合テスト
+
+## 💡 設計ノート
+
+### JIT実装の特徴
+- **Cranelift統合**: Wasmtime/Craneliftエコシステム活用
+- **ホストコール最適化**: Rustネイティブ関数との高速ブリッジ
+- **メモリ管理**: GCとJITの協調動作
+- **デバッグ支援**: JIT統計・トレース機能
+
+### 将来的な価値
+- **高速実行**: 本格運用時の性能向上
+- **AOTコンパイル**: ネイティブバイナリ生成
+- **WebAssembly統合**: WASM実行環境との統一
+
+## 📋 関連Issue・PR
+- JIT/Craneliftビルドエラー修正が必要
+- AIエージェント向けドキュメント整備
+- Phase 15完了後の復活検討
+
+---
+
+**Note**: このアーカイブは一時的な措置です。Phase 15完了後、JIT/Craneliftの復活と最新化を検討します。
\ No newline at end of file
diff --git a/build_jit.sh b/archive/jit-cranelift/scripts/build_jit.sh
similarity index 100%
rename from build_jit.sh
rename to archive/jit-cranelift/scripts/build_jit.sh
diff --git a/src/backend/cranelift/builder.rs b/archive/jit-cranelift/src/backend/cranelift/builder.rs
similarity index 100%
rename from src/backend/cranelift/builder.rs
rename to archive/jit-cranelift/src/backend/cranelift/builder.rs
diff --git a/src/backend/cranelift/context.rs b/archive/jit-cranelift/src/backend/cranelift/context.rs
similarity index 100%
rename from src/backend/cranelift/context.rs
rename to archive/jit-cranelift/src/backend/cranelift/context.rs
diff --git a/src/backend/cranelift/jit.rs b/archive/jit-cranelift/src/backend/cranelift/jit.rs
similarity index 100%
rename from src/backend/cranelift/jit.rs
rename to archive/jit-cranelift/src/backend/cranelift/jit.rs
diff --git a/src/backend/cranelift/mod.rs b/archive/jit-cranelift/src/backend/cranelift/mod.rs
similarity index 100%
rename from src/backend/cranelift/mod.rs
rename to archive/jit-cranelift/src/backend/cranelift/mod.rs
diff --git a/src/boxes/jit_config_box.rs b/archive/jit-cranelift/src/boxes/jit_config_box.rs
similarity index 100%
rename from src/boxes/jit_config_box.rs
rename to archive/jit-cranelift/src/boxes/jit_config_box.rs
diff --git a/src/boxes/jit_events_box.rs b/archive/jit-cranelift/src/boxes/jit_events_box.rs
similarity index 100%
rename from src/boxes/jit_events_box.rs
rename to archive/jit-cranelift/src/boxes/jit_events_box.rs
diff --git a/src/boxes/jit_hostcall_registry_box.rs b/archive/jit-cranelift/src/boxes/jit_hostcall_registry_box.rs
similarity index 100%
rename from src/boxes/jit_hostcall_registry_box.rs
rename to archive/jit-cranelift/src/boxes/jit_hostcall_registry_box.rs
diff --git a/src/boxes/jit_policy_box.rs b/archive/jit-cranelift/src/boxes/jit_policy_box.rs
similarity index 100%
rename from src/boxes/jit_policy_box.rs
rename to archive/jit-cranelift/src/boxes/jit_policy_box.rs
diff --git a/src/boxes/jit_stats_box.rs b/archive/jit-cranelift/src/boxes/jit_stats_box.rs
similarity index 100%
rename from src/boxes/jit_stats_box.rs
rename to archive/jit-cranelift/src/boxes/jit_stats_box.rs
diff --git a/src/boxes/jit_strict_box.rs b/archive/jit-cranelift/src/boxes/jit_strict_box.rs
similarity index 100%
rename from src/boxes/jit_strict_box.rs
rename to archive/jit-cranelift/src/boxes/jit_strict_box.rs
diff --git a/src/jit/abi.rs b/archive/jit-cranelift/src/jit/abi.rs
similarity index 100%
rename from src/jit/abi.rs
rename to archive/jit-cranelift/src/jit/abi.rs
diff --git a/src/jit/boundary.rs b/archive/jit-cranelift/src/jit/boundary.rs
similarity index 100%
rename from src/jit/boundary.rs
rename to archive/jit-cranelift/src/jit/boundary.rs
diff --git a/src/jit/config.rs b/archive/jit-cranelift/src/jit/config.rs
similarity index 100%
rename from src/jit/config.rs
rename to archive/jit-cranelift/src/jit/config.rs
diff --git a/src/jit/engine.rs b/archive/jit-cranelift/src/jit/engine.rs
similarity index 100%
rename from src/jit/engine.rs
rename to archive/jit-cranelift/src/jit/engine.rs
diff --git a/src/jit/events.rs b/archive/jit-cranelift/src/jit/events.rs
similarity index 100%
rename from src/jit/events.rs
rename to archive/jit-cranelift/src/jit/events.rs
diff --git a/src/jit/extern/async.rs b/archive/jit-cranelift/src/jit/extern/async.rs
similarity index 100%
rename from src/jit/extern/async.rs
rename to archive/jit-cranelift/src/jit/extern/async.rs
diff --git a/src/jit/extern/birth.rs b/archive/jit-cranelift/src/jit/extern/birth.rs
similarity index 100%
rename from src/jit/extern/birth.rs
rename to archive/jit-cranelift/src/jit/extern/birth.rs
diff --git a/src/jit/extern/collections.rs b/archive/jit-cranelift/src/jit/extern/collections.rs
similarity index 100%
rename from src/jit/extern/collections.rs
rename to archive/jit-cranelift/src/jit/extern/collections.rs
diff --git a/src/jit/extern/handles.rs b/archive/jit-cranelift/src/jit/extern/handles.rs
similarity index 100%
rename from src/jit/extern/handles.rs
rename to archive/jit-cranelift/src/jit/extern/handles.rs
diff --git a/src/jit/extern/host_bridge.rs b/archive/jit-cranelift/src/jit/extern/host_bridge.rs
similarity index 100%
rename from src/jit/extern/host_bridge.rs
rename to archive/jit-cranelift/src/jit/extern/host_bridge.rs
diff --git a/src/jit/extern/mod.rs b/archive/jit-cranelift/src/jit/extern/mod.rs
similarity index 100%
rename from src/jit/extern/mod.rs
rename to archive/jit-cranelift/src/jit/extern/mod.rs
diff --git a/src/jit/extern/result.rs b/archive/jit-cranelift/src/jit/extern/result.rs
similarity index 100%
rename from src/jit/extern/result.rs
rename to archive/jit-cranelift/src/jit/extern/result.rs
diff --git a/src/jit/extern/runtime.rs b/archive/jit-cranelift/src/jit/extern/runtime.rs
similarity index 100%
rename from src/jit/extern/runtime.rs
rename to archive/jit-cranelift/src/jit/extern/runtime.rs
diff --git a/src/jit/hostcall_registry.rs b/archive/jit-cranelift/src/jit/hostcall_registry.rs
similarity index 100%
rename from src/jit/hostcall_registry.rs
rename to archive/jit-cranelift/src/jit/hostcall_registry.rs
diff --git a/src/jit/lower/builder.rs b/archive/jit-cranelift/src/jit/lower/builder.rs
similarity index 100%
rename from src/jit/lower/builder.rs
rename to archive/jit-cranelift/src/jit/lower/builder.rs
diff --git a/src/jit/lower/builder/cranelift.rs b/archive/jit-cranelift/src/jit/lower/builder/cranelift.rs
similarity index 100%
rename from src/jit/lower/builder/cranelift.rs
rename to archive/jit-cranelift/src/jit/lower/builder/cranelift.rs
diff --git a/src/jit/lower/builder/noop.rs b/archive/jit-cranelift/src/jit/lower/builder/noop.rs
similarity index 100%
rename from src/jit/lower/builder/noop.rs
rename to archive/jit-cranelift/src/jit/lower/builder/noop.rs
diff --git a/src/jit/lower/builder/object.rs b/archive/jit-cranelift/src/jit/lower/builder/object.rs
similarity index 100%
rename from src/jit/lower/builder/object.rs
rename to archive/jit-cranelift/src/jit/lower/builder/object.rs
diff --git a/src/jit/lower/builder/rt_shims.rs b/archive/jit-cranelift/src/jit/lower/builder/rt_shims.rs
similarity index 100%
rename from src/jit/lower/builder/rt_shims.rs
rename to archive/jit-cranelift/src/jit/lower/builder/rt_shims.rs
diff --git a/src/jit/lower/builder/tls.rs b/archive/jit-cranelift/src/jit/lower/builder/tls.rs
similarity index 100%
rename from src/jit/lower/builder/tls.rs
rename to archive/jit-cranelift/src/jit/lower/builder/tls.rs
diff --git a/src/jit/lower/cfg_dot.rs b/archive/jit-cranelift/src/jit/lower/cfg_dot.rs
similarity index 100%
rename from src/jit/lower/cfg_dot.rs
rename to archive/jit-cranelift/src/jit/lower/cfg_dot.rs
diff --git a/src/jit/lower/core.rs b/archive/jit-cranelift/src/jit/lower/core.rs
similarity index 100%
rename from src/jit/lower/core.rs
rename to archive/jit-cranelift/src/jit/lower/core.rs
diff --git a/src/jit/lower/core/analysis.rs b/archive/jit-cranelift/src/jit/lower/core/analysis.rs
similarity index 100%
rename from src/jit/lower/core/analysis.rs
rename to archive/jit-cranelift/src/jit/lower/core/analysis.rs
diff --git a/src/jit/lower/core/cfg.rs b/archive/jit-cranelift/src/jit/lower/core/cfg.rs
similarity index 100%
rename from src/jit/lower/core/cfg.rs
rename to archive/jit-cranelift/src/jit/lower/core/cfg.rs
diff --git a/src/jit/lower/core/ops_ext.rs b/archive/jit-cranelift/src/jit/lower/core/ops_ext.rs
similarity index 100%
rename from src/jit/lower/core/ops_ext.rs
rename to archive/jit-cranelift/src/jit/lower/core/ops_ext.rs
diff --git a/src/jit/lower/core/string_len.rs b/archive/jit-cranelift/src/jit/lower/core/string_len.rs
similarity index 100%
rename from src/jit/lower/core/string_len.rs
rename to archive/jit-cranelift/src/jit/lower/core/string_len.rs
diff --git a/src/jit/lower/core_hostcall.rs b/archive/jit-cranelift/src/jit/lower/core_hostcall.rs
similarity index 100%
rename from src/jit/lower/core_hostcall.rs
rename to archive/jit-cranelift/src/jit/lower/core_hostcall.rs
diff --git a/src/jit/lower/core_ops.rs b/archive/jit-cranelift/src/jit/lower/core_ops.rs
similarity index 100%
rename from src/jit/lower/core_ops.rs
rename to archive/jit-cranelift/src/jit/lower/core_ops.rs
diff --git a/src/jit/lower/extern_thunks.rs b/archive/jit-cranelift/src/jit/lower/extern_thunks.rs
similarity index 100%
rename from src/jit/lower/extern_thunks.rs
rename to archive/jit-cranelift/src/jit/lower/extern_thunks.rs
diff --git a/src/jit/lower/mod.rs b/archive/jit-cranelift/src/jit/lower/mod.rs
similarity index 100%
rename from src/jit/lower/mod.rs
rename to archive/jit-cranelift/src/jit/lower/mod.rs
diff --git a/src/jit/manager.rs b/archive/jit-cranelift/src/jit/manager.rs
similarity index 100%
rename from src/jit/manager.rs
rename to archive/jit-cranelift/src/jit/manager.rs
diff --git a/src/jit/mod.rs b/archive/jit-cranelift/src/jit/mod.rs
similarity index 100%
rename from src/jit/mod.rs
rename to archive/jit-cranelift/src/jit/mod.rs
diff --git a/src/jit/observe.rs b/archive/jit-cranelift/src/jit/observe.rs
similarity index 100%
rename from src/jit/observe.rs
rename to archive/jit-cranelift/src/jit/observe.rs
diff --git a/src/jit/policy.rs b/archive/jit-cranelift/src/jit/policy.rs
similarity index 100%
rename from src/jit/policy.rs
rename to archive/jit-cranelift/src/jit/policy.rs
diff --git a/src/jit/policy/invoke.rs b/archive/jit-cranelift/src/jit/policy/invoke.rs
similarity index 100%
rename from src/jit/policy/invoke.rs
rename to archive/jit-cranelift/src/jit/policy/invoke.rs
diff --git a/src/jit/rt.rs b/archive/jit-cranelift/src/jit/rt.rs
similarity index 100%
rename from src/jit/rt.rs
rename to archive/jit-cranelift/src/jit/rt.rs
diff --git a/src/jit/semantics/clif.rs b/archive/jit-cranelift/src/jit/semantics/clif.rs
similarity index 100%
rename from src/jit/semantics/clif.rs
rename to archive/jit-cranelift/src/jit/semantics/clif.rs
diff --git a/src/jit/semantics/mod.rs b/archive/jit-cranelift/src/jit/semantics/mod.rs
similarity index 100%
rename from src/jit/semantics/mod.rs
rename to archive/jit-cranelift/src/jit/semantics/mod.rs
diff --git a/src/jit/shim_trace.rs b/archive/jit-cranelift/src/jit/shim_trace.rs
similarity index 100%
rename from src/jit/shim_trace.rs
rename to archive/jit-cranelift/src/jit/shim_trace.rs
diff --git a/src/semantics/clif_adapter.rs b/archive/jit-cranelift/src/semantics/clif_adapter.rs
similarity index 100%
rename from src/semantics/clif_adapter.rs
rename to archive/jit-cranelift/src/semantics/clif_adapter.rs
diff --git a/tools/jit_compare_smoke.sh b/archive/jit-cranelift/tools/jit_compare_smoke.sh
similarity index 100%
rename from tools/jit_compare_smoke.sh
rename to archive/jit-cranelift/tools/jit_compare_smoke.sh
diff --git a/archive/jit-cranelift/tools/smokes/jit_smoke.sh b/archive/jit-cranelift/tools/smokes/jit_smoke.sh
new file mode 100644
index 00000000..113d1e2a
--- /dev/null
+++ b/archive/jit-cranelift/tools/smokes/jit_smoke.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Archived: JIT smoke (not maintained in current phase). Kept for reference.
+set -euo pipefail
+
+SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+ROOT_DIR=$(CDPATH= cd -- "$SCRIPT_DIR/../../" && pwd)
+
+BIN="$ROOT_DIR/target/release/nyash"
+if [ ! -x "$BIN" ]; then
+  echo "Building nyash (release, JIT)..." >&2
+  cargo build --release --features cranelift-jit >/dev/null
+fi
+
+echo "[JIT Smoke] Core VM/JIT (plugins disabled)" >&2
+NYASH_DISABLE_PLUGINS=1 NYASH_CLI_VERBOSE=1 "$ROOT_DIR/tools/smokes/archive/smoke_vm_jit.sh" >/tmp/nyash-jit-core.out
+grep -q '^✅ smoke done' /tmp/nyash-jit-core.out || { echo "FAIL: core VM/JIT smoke" >&2; cat /tmp/nyash-jit-core.out; exit 1; }
+echo "PASS: core VM/JIT smoke" >&2
+
+echo "All PASS (archived JIT smoke)" >&2
+
diff --git a/src/boxes/debug_box.rs b/src/boxes/debug_box.rs
index 9fed8efc..57710721 100644
--- a/src/boxes/debug_box.rs
+++ b/src/boxes/debug_box.rs
@@ -328,17 +328,18 @@ impl DebugBox {
 
     // --- Phase 1: JIT/Plugin shim tracing ---
     pub fn trace_plugin_calls(&self, on: bool) -> Result<Box<dyn NyashBox>, RuntimeError> {
-        crate::jit::shim_trace::set_enabled(on);
+        // ARCHIVED: JIT functionality moved to archive/jit-cranelift/
         println!(
-            "[DEBUG] JIT shim trace: {}",
+            "[DEBUG] JIT shim trace: {} (JIT ARCHIVED - no-op)",
             if on { "ENABLED" } else { "DISABLED" }
         );
         Ok(Box::new(VoidBox::new()))
     }
 
     pub fn get_jit_events(&self) -> Result<Box<dyn NyashBox>, RuntimeError> {
-        let s = crate::jit::shim_trace::snapshot_joined();
-        Ok(Box::new(StringBox::new(s)))
+        // ARCHIVED: JIT functionality moved to archive/jit-cranelift/
+        let s = "[JIT ARCHIVED] No JIT events available - JIT moved to archive/jit-cranelift/";
+        Ok(Box::new(StringBox::new(s.to_string())))
     }
 }
 
diff --git a/src/boxes/mod.rs b/src/boxes/mod.rs
index 4ea1acff..612c9b9d 100644
--- a/src/boxes/mod.rs
+++ b/src/boxes/mod.rs
@@ -73,12 +73,13 @@ pub mod console_box;
 pub mod debug_config_box;
 pub mod function_box;
 pub mod gc_config_box;
-pub mod jit_config_box;
-pub mod jit_events_box;
-pub mod jit_hostcall_registry_box;
-pub mod jit_policy_box;
-pub mod jit_stats_box;
-pub mod jit_strict_box;
+// ARCHIVED: JIT Box modules moved to archive/jit-cranelift/ during Phase 15
+// pub mod jit_config_box;
+// pub mod jit_events_box;
+// pub mod jit_hostcall_registry_box;
+// pub mod jit_policy_box;
+// pub mod jit_stats_box;
+// pub mod jit_strict_box;
 pub mod map_box;
 #[cfg(not(target_arch = "wasm32"))]
 pub mod qr_box;
diff --git a/src/lib.rs b/src/lib.rs
index e95c6160..a51733cd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -48,7 +48,7 @@ pub mod mir_aot_plan_import {
 
 // Backends
 pub mod backend;
-pub mod jit; // Cranelift JIT subsystem (skeleton)
+// pub mod jit; // ARCHIVED: Cranelift JIT subsystem moved to archive/jit-cranelift/
 pub mod semantics; // Unified semantics trait for MIR evaluation/lowering
 
 pub mod benchmarks;
diff --git a/src/semantics/mod.rs b/src/semantics/mod.rs
index 34b9632d..c39d2662 100644
--- a/src/semantics/mod.rs
+++ b/src/semantics/mod.rs
@@ -84,5 +84,5 @@ pub trait SemanticsExt: Semantics {
 
 impl<T: Semantics> SemanticsExt for T {}
 
-pub mod clif_adapter;
+// pub mod clif_adapter; // ARCHIVED: moved to archive/jit-cranelift/
 pub mod vm_impl;