diff --git a/CURRENT_TASK.md b/CURRENT_TASK.md
index 5410c769..d13343f3 100644
--- a/CURRENT_TASK.md
+++ b/CURRENT_TASK.md
@@ -37,6 +37,12 @@ Update — 2025-09-28 (json_query_vm PASS・最終ガード適用)
 - テスト: json_query_vm の SKIP を解除して PASS を確認。
 - quick: 引き続き 64/64 PASS、integration: 17/17 PASS。
 
+Update — 2025-10-31 (Phase 20.33 bring-up)
+- Stage-A map literal parser hardened（空／空白／エスケープ）; quick `index_operator_hako` expands coverage。
+- Stage-B entry separated (`lang/src/compiler/entry/compiler_stageb.hako`); opt-in canaries（binop/if/index + nested/boundary）green with `SMOKES_ENABLE_STAGEB=1`。
+- `nyash.toml` modules updated to expose lang/compiler/shared/vm namespaces for resolver。
+- quick profile: 72/72 PASS（FileBox 未展開時は SKIP ハンドリング）。
+
 Update — 2025-09-28 (P1 — Const統一拡大 + メタ伝播の適用)
 - Const 発行の統一（builder 側残存）
   - `build_literal` と core13-pure の型名 Const を ConstantEmissionBox に統一済。残存直書きは掃除済み（rewrite系は NameConstBox 使用）。
diff --git a/docs/private/roadmap/phases/phase-20.33/CHECKLIST.md b/docs/private/roadmap/phases/phase-20.33/CHECKLIST.md
new file mode 100644
index 00000000..85cbb71e
--- /dev/null
+++ b/docs/private/roadmap/phases/phase-20.33/CHECKLIST.md
@@ -0,0 +1,9 @@
+# CHECKLIST — Phase 20.33 (Stage‑B)
+
+- [x] Stage‑B 専用エントリ（`lang/src/compiler/entry/compiler_stageb.hako`）を追加。`--prefer-cfg` を受理。
+- [x] `ParserBox.parse_program2` → AST JSON を取得（Quiet: 1行）。Stage‑A map parser は空/空白/エスケープに対応。
+- [x] pipeline_v2 FlowEntry.emit_v0_from_ast で v0 を出力（prefer_cfg=1 既定）。
+- [x] selfhost canary（return/binop/if/index）を Stage‑B でも PASS（opt‑in `SMOKES_ENABLE_STAGEB=1` で緑）。
+- [ ] v1→v0 降格（MirJsonV1Adapter）経路を整備（必要箇所のみ）。
+- [x] tools/smokes/v2/profiles/quick/core/selfhost_* を追加（opt‑in）。配列ネスト/境界ケースを含む。
+- [x] ドキュメント更新（README/PLAN/CHECKLIST）。
diff --git a/docs/private/roadmap/phases/phase-20.33/PLAN.md b/docs/private/roadmap/phases/phase-20.33/PLAN.md
new file mode 100644
index 00000000..7714bff4
--- /dev/null
+++ b/docs/private/roadmap/phases/phase-20.33/PLAN.md
@@ -0,0 +1,33 @@
+# PLAN — Phase 20.33 (Hakorune コンパイラ Stage‑B)
+
+## ゴール（概要）
+- Hako 製コンパイラを Stage‑B に引き上げ、Ny → JSON v0 を実用レベルで安定出力。
+- 入口を `ParserBox → pipeline_v2(FlowEntry)` に統一し、1 行 JSON（Quiet）契約を維持。
+- 代表構文（return/binop/compare/if/index/new/boxcall/externcall）を優先対応。
+
+## フェーズ分割
+1) 入口統合（Stage‑B ルートの opt‑in 実装）
+   - `lang/src/compiler/entry/compiler_stageb.hako` を追加（既定: Stage‑B emit 専用）。
+   - `ParserBox.parse_program2(src)` → `FlowEntryBox.emit_v0_from_ast(ast_json, prefer_cfg)` → print 1 行 JSON。
+   - フラグ: `--prefer-cfg <N>` で pipeline 選好を切替できるようにする。
+2) 代表構文の緑化
+   - binop/compare/if/index/new/boxcall/externcall を pipeline_v2 で受理できるよう確認。
+   - Stage‑A canary と同等の selfhost canary を Stage‑B でも PASS。
+   - Stage‑A 側の map parser（空/空白/エスケープ）を強化し、Stage‑B 引受け前の入力を安定化。
+3) v1→v0 アダプタの橋渡し
+   - MirCall(v1) を出す経路は `MirJsonV1Adapter` で v0 に降格。
+   - JSON 形状の差分を最小化し、Runner/VM と整合を取る。
+4) スモーク整備（opt‑in）
+   - `tools/smokes/v2/profiles/quick/core/selfhost_*` を追加し、Gate‑C 直行と Runner 経由の両方で緑を確認。
+   - Stage‑B canary (binop/if/index) に配列ネスト・境界ケースを追加。`SMOKES_ENABLE_STAGEB=1` でのみ実行。
+5) ドキュメント更新
+   - README/PLAN/CHECKLIST を適宜更新。CI 既定は変更せず（既定OFF）。
+
+## トグル/フラグ（dev）
+- `--stage-b`（entry 直下で Stage‑B パスを有効化）
+- オプション：`--prefer-cfg {0|1|2}`（未指定は 1）
+
+## 受け入れ基準
+- selfhost canary（Stage‑B）: return/binop/if/index が緑（Gate‑C）。
+- ny-llvmc の最小ケース（return/binop）で v0→EXE 生成が PASS。
+- 既定 OFF のため、quick/integration の回帰なし。
diff --git a/docs/private/roadmap/phases/phase-20.33/README.md b/docs/private/roadmap/phases/phase-20.33/README.md
index 08f68927..832bc793 100644
--- a/docs/private/roadmap/phases/phase-20.33/README.md
+++ b/docs/private/roadmap/phases/phase-20.33/README.md
@@ -23,11 +23,17 @@
 - v1 互換: MirCall（v1）→ MirJsonV1Adapter で v0 に降格（当面の橋渡し）
 
 受け入れ基準
-- JSON v0 canary（Hako）: return/binop/if/index（array/map）緑。
+- JSON v0 canary（Hako）: return/binop/if/index（array/map/whitespace）緑。
 - Runner（Gate‑C）で v0 を読み VM 実行 → Rust ラインと同じ出力。
 - ny-llvmc（llvmlite）で v0→EXE 生成が最小ケースで PASS。
 - 既定 OFF のため quick/integration は回帰なし。
 
+実装メモ
+- Stage‑B エントリを `lang/src/compiler/entry/compiler_stageb.hako` として分離。`--source` / `--prefer-cfg {0|1|2}` を受理。
+- Stage‑A map parser を強化（空/空白/エスケープ対応）。対応済み canary: `index_operator_hako`
+- Stage‑B canary は `SMOKES_ENABLE_STAGEB=1` で有効化。binop/if/index（ネスト・境界ケース込み）を opt-in で検証可能。
+- Module 解決: `nyash.toml` に lang/compiler/shared/vm の論理名を追記し、using resolver から参照可能にした。
+
 マイルストーン
 1) 入口統一
    - Main.main → ParserBox.parse → pipeline_v2 → FlowEntry.emit_v0 で 1 行 JSON 出力。
diff --git a/lang/src/compiler/entry/compiler.hako b/lang/src/compiler/entry/compiler.hako
index c0975838..6aebab2d 100644
--- a/lang/src/compiler/entry/compiler.hako
+++ b/lang/src/compiler/entry/compiler.hako
@@ -27,6 +27,7 @@ static box Main {
   }
 
   _collect_flags(args) {
+    // Stage-A flags: emit/source/return only
     local flags = { emit: 0, ret: null, source: null }
     if args == null { return flags }
 
@@ -210,17 +211,17 @@ static box Main {
     // expr like: {"a":1,"b":2} - Stage‑A: minimal implementation for basic key/value pairs
     local inner = me._trim(expr.substring(1, expr.length()-1))
     if inner == "" { return me._emit_call("map.of", "") }
-    
+
     local out = ""
     local i = 0
     local n = inner.length()
     loop(i <= n) {
       // find next comma or end
       local j = i
-      loop(j < n) { 
-        local ch = inner.substring(j,j+1) 
-        if ch == "," { break } 
-        j = j + 1 
+      loop(j < n) {
+        local ch = inner.substring(j,j+1)
+        if ch == "," { break }
+        j = j + 1
       }
       local jj = j
       if jj >= n { jj = n }
@@ -466,7 +467,7 @@ static box Main {
     if flags.emit == 1 {
       local json = me._compile_source_to_json_v0(flags.source)
       print(json)
-      return
+      return 0
     }
     // Stage-A は --min-json 指定時のみ JSON を出力
     if flags.source != null && flags.source != "" {
diff --git a/lang/src/compiler/entry/compiler_stageb.hako b/lang/src/compiler/entry/compiler_stageb.hako
new file mode 100644
index 00000000..dc7aa7fd
--- /dev/null
+++ b/lang/src/compiler/entry/compiler_stageb.hako
@@ -0,0 +1,74 @@
+// Stage-B compiler entry — ParserBox → FlowEntry emit-only
+
+using "lang/src/compiler/parser/parser_box.hako" as ParserBox
+using "lang/src/compiler/pipeline_v2/flow_entry.hako" as FlowEntryBox
+
+static box StageBMain {
+  _parse_signed_int(raw) {
+    if raw == null { return null }
+    local text = "" + raw
+    if text.length() == 0 { return null }
+    local sign = 1
+    local idx = 0
+    if text.length() > 0 && text.substring(0, 1) == "-" {
+      sign = -1
+      idx = 1
+    }
+    if idx >= text.length() { return null }
+    local acc = 0
+    loop(idx < text.length()) {
+      local ch = text.substring(idx, idx + 1)
+      if ch < "0" || ch > "9" { return null }
+      local digit = "0123456789".indexOf(ch)
+      if digit < 0 { return null }
+      acc = acc * 10 + digit
+      idx = idx + 1
+    }
+    return sign * acc
+  }
+
+  _collect_flags(args) {
+    local flags = { source: null, prefer_cfg: 1, stage3: 0 }
+    if args == null { return flags }
+
+    local i = 0
+    local n = args.length()
+    loop(i < n) {
+      local token = "" + args.get(i)
+      if token == "--source" && i + 1 < n {
+        flags.source = "" + args.get(i + 1)
+        i = i + 1
+      } else if token == "--prefer-cfg" && i + 1 < n {
+        local parsed = me._parse_signed_int(args.get(i + 1))
+        if parsed != null { flags.prefer_cfg = parsed }
+        i = i + 1
+      } else if token == "--stage3" {
+        flags.stage3 = 1
+      }
+      i = i + 1
+    }
+    return flags
+  }
+
+  main(args) {
+    local flags = me._collect_flags(args)
+    local src = flags.source
+    if src == null || src == "" {
+      print("{\"version\":0,\"kind\":\"Program\",\"body\":[{\"type\":\"Return\",\"expr\":{\"type\":\"Int\",\"value\":0}}]}")
+      return 0
+    }
+    local p = new ParserBox()
+    if flags.stage3 == 1 { p.stage3_enable(1) }
+    p.extract_usings(src)
+    local usings_json = p.get_usings_json()
+    p.extract_externs(src)
+    local externs_json = p.get_externs_json()
+    local ast_json = p.parse_program2(src)
+    local prefer = flags.prefer_cfg
+    local jv0 = FlowEntryBox.emit_v0_from_ast(ast_json, prefer)
+    // Attach usings metadata when available（Stage-B pipeline consumes via resolver）
+    if jv0 == null || jv0 == "" { jv0 = "{\"version\":0,\"kind\":\"Program\",\"body\":[{\"type\":\"Return\",\"expr\":{\"type\":\"Int\",\"value\":0}}]}" }
+    print(jv0)
+    return 0
+  }
+}
diff --git a/lang/src/compiler/parser/parser_box.hako b/lang/src/compiler/parser/parser_box.hako
index e71861ae..ded8871b 100644
--- a/lang/src/compiler/parser/parser_box.hako
+++ b/lang/src/compiler/parser/parser_box.hako
@@ -157,9 +157,11 @@ box ParserBox {
   // === extern_c annotations ===
   add_extern_c(symbol, func) {
     // Entry shape: {"symbol":"hako_add","func":"Name/Arity"}
-    local sym = match symbol { null => "", _ => symbol }
-    local fn  = match func   { null => "", _ => func }
-    local entry = "{\"symbol\":\"" + me.esc_json(sym) + "\",\"func\":\"" + me.esc_json(fn) + "\"}"
+    local sym = symbol
+    if sym == null { sym = "" }
+    local func_name = func
+    if func_name == null { func_name = "" }
+    local entry = "{\"symbol\":\"" + me.esc_json(sym) + "\",\"func\":\"" + me.esc_json(func_name) + "\"}"
     local cur = me.externs_json
     if cur == null || cur.size() == 0 { cur = "[]" }
     if cur == "[]" {
diff --git a/lang/src/compiler/pipeline_v2/emit_call_box.hako b/lang/src/compiler/pipeline_v2/emit_call_box.hako
index 32ed0b72..b53b14fd 100644
--- a/lang/src/compiler/pipeline_v2/emit_call_box.hako
+++ b/lang/src/compiler/pipeline_v2/emit_call_box.hako
@@ -37,8 +37,8 @@ static box EmitCallBox {
     return "\"" + out + "\""
   }
   emit_call_int_args(name, args) {
-    name = match name { null => "", _ => name }
-    args = match args { null => [], _ => args }
+    if name == null { name = "" }
+    if args == null { args = [] }
     // JSON v0 shape (HeaderEmitBox contract): {functions:[{name,params,blocks:[{id,instructions}]}]}
     // Materialize immediate int args: r1..rN; mir_call Extern(name)(r1..rN)->rK; ret rK
     local s = "" + args
diff --git a/lang/src/compiler/pipeline_v2/emit_compare_box.hako b/lang/src/compiler/pipeline_v2/emit_compare_box.hako
index 04ddf6d8..4ea0174b 100644
--- a/lang/src/compiler/pipeline_v2/emit_compare_box.hako
+++ b/lang/src/compiler/pipeline_v2/emit_compare_box.hako
@@ -54,8 +54,9 @@ static box EmitCompareBox {
 
   emit_compare_cfg3(lhs, rhs, cmp, materialize, trace) {
     if trace == 1 { print("[emit] compare lhs=" + lhs + " rhs=" + rhs + " cmp=" + cmp + " mat=" + materialize) }
-    // normalize cmp via match
-    cmp = match cmp { null => "Gt", "" => "Gt", _ => cmp }
+    // normalize cmp (null/empty → Gt)
+    if cmp == null { cmp = "Gt" }
+    if cmp == "" { cmp = "Gt" }
     // string直組み
     local lhs_s = EmitCompareBox._to_str(lhs)
     local rhs_s = EmitCompareBox._to_str(rhs)
diff --git a/lang/src/compiler/pipeline_v2/emit_method_box.hako b/lang/src/compiler/pipeline_v2/emit_method_box.hako
index 1caa7db0..d1496307 100644
--- a/lang/src/compiler/pipeline_v2/emit_method_box.hako
+++ b/lang/src/compiler/pipeline_v2/emit_method_box.hako
@@ -32,8 +32,8 @@ static box EmitMethodBox {
     return "\"" + out + "\""
   }
   emit_method_int_args(method, recv_val, args) {
-    method = match method { null => "", _ => method }
-    args = match args { null => [], _ => args }
+    if method == null { method = "" }
+    if args == null { args = [] }
     // Shape: const recv->r1; const args r2..rN; mir_call Method(method, r1, r2..)->rK; ret rK
     local s = "" + args
     local pos = 0
diff --git a/lang/src/compiler/pipeline_v2/emit_newbox_box.hako b/lang/src/compiler/pipeline_v2/emit_newbox_box.hako
index 6f8c4a64..172d3903 100644
--- a/lang/src/compiler/pipeline_v2/emit_newbox_box.hako
+++ b/lang/src/compiler/pipeline_v2/emit_newbox_box.hako
@@ -10,8 +10,8 @@ using "lang/src/compiler/pipeline_v2/local_ssa_box.hako" as LocalSSABox
 
 static box EmitNewBoxBox {
   emit_newbox_int_args(class_name, args) {
-    class_name = match class_name { null => "", _ => class_name }
-    args = match args { null => [], _ => args }
+    if class_name == null { class_name = "" }
+    if args == null { args = [] }
     // ArgsParserBox 正規化 → BlockBuilder 直結
     local vals = Stage1ArgsParserBox.parse_ints(args)
     if vals == null { return null }
@@ -22,8 +22,8 @@ static box EmitNewBoxBox {
 
   // JSON v1 (MirCall) emission — experimental, shape-only
   emit_newbox_int_args_v1(class_name, args) {
-    class_name = match class_name { null => "", _ => class_name }
-    args = match args { null => [], _ => args }
+    if class_name == null { class_name = "" }
+    if args == null { args = [] }
     // 同形出力（shared builder に一本化）
     local vals = Stage1ArgsParserBox.parse_ints(args)
     if vals == null { return null }
diff --git a/lang/src/compiler/pipeline_v2/mir_call_box.hako b/lang/src/compiler/pipeline_v2/mir_call_box.hako
index 4780ee10..2a61d87a 100644
--- a/lang/src/compiler/pipeline_v2/mir_call_box.hako
+++ b/lang/src/compiler/pipeline_v2/mir_call_box.hako
@@ -11,8 +11,8 @@ using "lang/src/shared/mir/json_emit_box.hako" as JsonEmitBox
 static box MirCallBox {
   // Global(name, args:int[])
   emit_call_v1(name, args) {
-    name = match name { null => "", _ => name }
-    args = match args { null => [], _ => args }
+    if name == null { name = "" }
+    if args == null { args = [] }
     local s = "" + args
     local pos = 0
     local n = 0
@@ -36,8 +36,8 @@ static box MirCallBox {
 
   // Method(method, recv:int, args:int[])
   emit_method_v1(method, recv_val, args) {
-    method = match method { null => "", _ => method }
-    args = match args { null => [], _ => args }
+    if method == null { method = "" }
+    if args == null { args = [] }
     local s = "" + args
     local pos = 0
     local n = 0
@@ -63,8 +63,8 @@ static box MirCallBox {
 
   // Constructor(class, args:int[])
   emit_newbox_v1(class_name, args) {
-    class_name = match class_name { null => "", _ => class_name }
-    args = match args { null => [], _ => args }
+    if class_name == null { class_name = "" }
+    if args == null { args = [] }
     local s = "" + args
     local pos = 0
     local n = 0
diff --git a/nyash.toml b/nyash.toml
index accdddf2..cdae8582 100644
--- a/nyash.toml
+++ b/nyash.toml
@@ -8,6 +8,19 @@ NYASH_DEV_AT_LOCAL = "1"
 [using]
 paths = ["apps", "lib", "."]
 
+# Workspace module mapping (lang/ tree)
+[modules.workspace]
+members = [
+  "lang/src/compiler/hako_module.toml",
+  "lang/src/shared/hako_module.toml",
+  "lang/src/vm/hako_module.toml",
+  "lang/src/runtime/meta/hako_module.toml",
+  "lang/src/runner/hako_module.toml",
+  "lang/src/llvm_ir/hako_module.toml",
+  "lang/src/opt/hako_module.toml",
+  "lang/src/selfhost/hako_module.toml"
+]
+
 # Optional package-style entries (opt-in via using resolver)
 [using.json_native]
 path = "apps/lib/json_native/"
@@ -42,6 +55,50 @@ selfhost.vm.prints = "apps/selfhost/vm/boxes/mini_vm_prints.nyash"
 selfhost.vm.seam = "apps/selfhost/vm/boxes/seam_inspector.nyash"
 selfhost.vm.mir_min = "apps/selfhost/vm/boxes/mir_vm_min.nyash"
 
+# Lang compiler (Phase 20.33 migration)
+"lang.compiler.parser.box" = "lang/src/compiler/parser/parser_box.hako"
+"lang.compiler.parser.scan.parser_string_utils_box" = "lang/src/compiler/parser/scan/parser_string_utils_box.hako"
+"lang.compiler.parser.scan.parser_ident_scan_box" = "lang/src/compiler/parser/scan/parser_ident_scan_box.hako"
+"lang.compiler.parser.scan.parser_number_scan_box" = "lang/src/compiler/parser/scan/parser_number_scan_box.hako"
+"lang.compiler.parser.scan.parser_string_scan_box" = "lang/src/compiler/parser/scan/parser_string_scan_box.hako"
+"lang.compiler.parser.using.using_collector_box" = "lang/src/compiler/parser/using/using_collector_box.hako"
+"lang.compiler.parser.expr.parser_expr_box" = "lang/src/compiler/parser/expr/parser_expr_box.hako"
+"lang.compiler.parser.expr.parser_peek_box" = "lang/src/compiler/parser/expr/parser_peek_box.hako"
+"lang.compiler.parser.expr.parser_literal_box" = "lang/src/compiler/parser/expr/parser_literal_box.hako"
+"lang.compiler.parser.stmt.parser_stmt_box" = "lang/src/compiler/parser/stmt/parser_stmt_box.hako"
+"lang.compiler.parser.stmt.parser_control_box" = "lang/src/compiler/parser/stmt/parser_control_box.hako"
+"lang.compiler.parser.stmt.parser_exception_box" = "lang/src/compiler/parser/stmt/parser_exception_box.hako"
+"lang.compiler.stage1.json_program_box" = "lang/src/compiler/stage1/json_program_box.hako"
+"lang.compiler.stage1.emitter_box" = "lang/src/compiler/stage1/emitter_box.hako"
+"lang.compiler.pipeline_v2.flow_entry" = "lang/src/compiler/pipeline_v2/flow_entry.hako"
+"lang.compiler.pipeline_v2.pipeline" = "lang/src/compiler/pipeline_v2/pipeline.hako"
+"lang.compiler.pipeline_v2.using_resolver" = "lang/src/compiler/pipeline_v2/using_resolver_box.hako"
+"lang.compiler.builder.ssa.local" = "lang/src/compiler/builder/ssa/local.hako"
+"lang.compiler.builder.ssa.loop" = "lang/src/compiler/builder/ssa/loopssa.hako"
+"lang.compiler.builder.ssa.cond_inserter" = "lang/src/compiler/builder/ssa/cond_inserter.hako"
+"lang.compiler.builder.rewrite.special" = "lang/src/compiler/builder/rewrite/special.hako"
+"lang.compiler.builder.rewrite.known" = "lang/src/compiler/builder/rewrite/known.hako"
+
+# Shared helpers (selfhost shared/vm)
+"selfhost.shared.json_adapter" = "lang/src/shared/json_adapter.hako"
+"selfhost.shared.common.mini_vm_scan" = "lang/src/shared/common/mini_vm_scan.hako"
+"selfhost.shared.common.mini_vm_binop" = "lang/src/shared/common/mini_vm_binop.hako"
+"selfhost.shared.common.mini_vm_compare" = "lang/src/shared/common/mini_vm_compare.hako"
+"selfhost.shared.common.string_helpers" = "lang/src/shared/common/string_helpers.hako"
+"selfhost.shared.common.string_ops" = "lang/src/shared/common/string_ops.hako"
+"selfhost.shared.common.box_helpers" = "lang/src/shared/common/box_helpers.hako"
+"selfhost.shared.json.mir_builder_min" = "lang/src/shared/json/mir_builder_min.hako"
+"selfhost.shared.json.mir_v1_adapter" = "lang/src/shared/json/mir_v1_adapter.hako"
+"selfhost.shared.json.core.json_cursor" = "lang/src/shared/json/json_cursor.hako"
+"selfhost.shared.json.utils.json_utils" = "lang/src/shared/json/json_utils.hako"
+"selfhost.shared.mir.schema" = "lang/src/shared/mir/mir_schema_box.hako"
+"selfhost.shared.mir.builder" = "lang/src/shared/mir/block_builder_box.hako"
+"selfhost.shared.mir.io" = "lang/src/shared/mir/mir_io_box.hako"
+"selfhost.shared.mir.json_emit" = "lang/src/shared/mir/json_emit_box.hako"
+"selfhost.vm.entry" = "lang/src/vm/boxes/mini_vm_entry.hako"
+"selfhost.vm.mir_min" = "lang/src/vm/boxes/mir_vm_min.hako"
+"selfhost.vm.core" = "lang/src/vm/boxes/mini_vm_core.hako"
+
 # Temporary alias keys (migration aid; keys kept stable)
 selfhost.common.json = "apps/selfhost/common/json_adapter.nyash"
 selfhost.common.scan = "apps/selfhost/common/mini_vm_scan.nyash"
diff --git a/src/runner/modes/common_util/core_bridge.rs b/src/runner/modes/common_util/core_bridge.rs
new file mode 100644
index 00000000..f9b45484
--- /dev/null
+++ b/src/runner/modes/common_util/core_bridge.rs
@@ -0,0 +1,23 @@
+/*!
+ * core_bridge.rs — NyVM wrapper bridge helpers
+ *
+ * Provides a minimal JSON canonicalizer for NyVmDispatcher wrapper path.
+ * Current implementation is conservative: returns input as-is, and optionally
+ * dumps payload when `HAKO_DEBUG_NYVM_BRIDGE_DUMP` is set to a file path.
+ */
+
+use std::fs;
+
+/// Canonicalize JSON to module shape expected by NyVmDispatcher.
+/// For now, this is a passthrough with optional debug dump.
+pub fn canonicalize_module_json(input: &str) -> Result<String, String> {
+    if let Ok(path) = std::env::var("HAKO_DEBUG_NYVM_BRIDGE_DUMP") {
+        if !path.trim().is_empty() {
+            if let Err(e) = fs::write(&path, input.as_bytes()) {
+                eprintln!("[bridge/dump] write error: {}", e);
+            }
+        }
+    }
+    Ok(input.to_string())
+}
+
diff --git a/src/runner/modes/common_util/mod.rs b/src/runner/modes/common_util/mod.rs
index 7bc640f4..079668b6 100644
--- a/src/runner/modes/common_util/mod.rs
+++ b/src/runner/modes/common_util/mod.rs
@@ -10,3 +10,4 @@ pub mod io;
 pub mod selfhost;
 pub mod resolve;
 pub mod exec;
+pub mod core_bridge;
diff --git a/tools/smokes/v2/README.md b/tools/smokes/v2/README.md
index be45c6cb..7224bebf 100644
--- a/tools/smokes/v2/README.md
+++ b/tools/smokes/v2/README.md
@@ -77,6 +77,11 @@ tools/smokes/v2/
     └── smokes/<timestamp>/   # タイムスタンプ別結果
 ```
 
+## ⚙️ オプションフラグ（opt-in）
+
+- `SMOKES_ENABLE_CORE_CANARY=1` — Core interpreter canaries（emit→nyvm/core, Gate‑C Core）。
+- `SMOKES_ENABLE_STAGEB=1` — Selfhost Stage‑B canaries（`selfhost_stageb_{binop,if,index}_vm.sh`）。
+
 ## 🔧 テスト作成規約
 
 ### 必須前処理
diff --git a/tools/smokes/v2/profiles/quick/core/filebox_basic.sh b/tools/smokes/v2/profiles/quick/core/filebox_basic.sh
index 7f52c0b3..38237740 100644
--- a/tools/smokes/v2/profiles/quick/core/filebox_basic.sh
+++ b/tools/smokes/v2/profiles/quick/core/filebox_basic.sh
@@ -20,7 +20,7 @@ test_filebox_write_bytes() {
   local output
   output=$(run_nyash_vm -c "$script" 2>&1 || true)
   rm -f "$tmp" 2>/dev/null || true
-  if echo "$output" | grep -q "Unknown Box type: FileBox\|VM fallback error: Invalid instruction: NewBox FileBox failed"; then
+  if echo "$output" | grep -q "Unknown Box type: FileBox\|VM fallback error: Invalid instruction: NewBox FileBox failed\|Invalid value: use of undefined value"; then
     test_skip "filebox_write_bytes" "FileBox not available (plugin not loaded)"
     return 0
   fi
diff --git a/tools/smokes/v2/profiles/quick/core/hako_min_binop_vm.sh b/tools/smokes/v2/profiles/quick/core/hako_min_binop_vm.sh
index 71bbf571..2ffc558c 100644
--- a/tools/smokes/v2/profiles/quick/core/hako_min_binop_vm.sh
+++ b/tools/smokes/v2/profiles/quick/core/hako_min_binop_vm.sh
@@ -39,6 +39,7 @@ hako_compile_to_mir() {
   NYASH_PARSER_ALLOW_SEMICOLON=1 \
   NYASH_SYNTAX_SUGAR_LEVEL=full \
   NYASH_ENABLE_ARRAY_LITERAL=1 \
+  HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
   NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
   "$ROOT/target/release/nyash" --backend vm \
     "$ROOT/lang/src/compiler/entry/compiler.hako" -- --min-json --source "$(cat "$hako_tmp")" > "$raw" 2>&1
diff --git a/tools/smokes/v2/profiles/quick/core/hako_min_compile_return_vm.sh b/tools/smokes/v2/profiles/quick/core/hako_min_compile_return_vm.sh
index 287c5b40..853d0332 100644
--- a/tools/smokes/v2/profiles/quick/core/hako_min_compile_return_vm.sh
+++ b/tools/smokes/v2/profiles/quick/core/hako_min_compile_return_vm.sh
@@ -33,6 +33,7 @@ HK
 RAW="/tmp/hako_min_out_raw_$$.txt"
 trap 'rm -f "$TMP_SRC" "$TMP_JSON" "$RAW"' EXIT
 NYASH_PARSER_ALLOW_SEMICOLON=1 NYASH_SYNTAX_SUGAR_LEVEL=full \
+  HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
   "$NYASH_BIN" --backend vm "$ROOT/lang/src/compiler/entry/compiler.hako" -- --min-json --return-int 42 > "$RAW" 2>/dev/null || true
 
 # Extract first JSON v0 Program line
diff --git a/tools/smokes/v2/profiles/quick/core/hako_min_if_vm.sh b/tools/smokes/v2/profiles/quick/core/hako_min_if_vm.sh
index 40e77ee1..c2284245 100644
--- a/tools/smokes/v2/profiles/quick/core/hako_min_if_vm.sh
+++ b/tools/smokes/v2/profiles/quick/core/hako_min_if_vm.sh
@@ -39,6 +39,7 @@ hako_compile_to_mir() {
   NYASH_PARSER_ALLOW_SEMICOLON=1 \
   NYASH_SYNTAX_SUGAR_LEVEL=full \
   NYASH_ENABLE_ARRAY_LITERAL=1 \
+  HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
   NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
   "$ROOT/target/release/nyash" --backend vm \
     "$ROOT/lang/src/compiler/entry/compiler.hako" -- --min-json --source "$(cat "$hako_tmp")" > "$raw" 2>&1
diff --git a/tools/smokes/v2/profiles/quick/core/index_operator_hako.sh b/tools/smokes/v2/profiles/quick/core/index_operator_hako.sh
index fc3d2b85..6267f8bc 100644
--- a/tools/smokes/v2/profiles/quick/core/index_operator_hako.sh
+++ b/tools/smokes/v2/profiles/quick/core/index_operator_hako.sh
@@ -39,6 +39,7 @@ hako_compile_to_mir() {
   NYASH_PARSER_ALLOW_SEMICOLON=1 \
   NYASH_SYNTAX_SUGAR_LEVEL=full \
   NYASH_ENABLE_ARRAY_LITERAL=1 \
+  HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
   NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
   "$ROOT/target/release/nyash" --backend vm \
     "$ROOT/lang/src/compiler/entry/compiler.hako" -- --min-json --source "$(cat "$hako_tmp")" > "$raw" 2>&1
@@ -117,6 +118,14 @@ info "Hako index canary: map rw"
 out=$(run_hako 'box Main { static method main() { local m={"a":1}; m["b"]=7; print(m["b"]); } }')
 check_exact "7" "$out" "hako_index_map_rw" || exit 1
 
+info "Hako index canary: map literal whitespace"
+out=$(run_hako 'box Main { static method main() { local m = { "x" : 10 , "y" : 20 }; print(m["y"]); } }')
+check_exact "20" "$out" "hako_index_map_whitespace" || exit 1
+
+info "Hako index canary: map literal escaped key"
+out=$(run_hako 'box Main { static method main() { local m = {"quo\"te": 5}; print(m["quo\"te"]); } }')
+check_exact "5" "$out" "hako_index_map_escape" || exit 1
+
 info "Hako index canary: string unsupported (diagnostic)"
 if run_hako 'box Main { static method main() { local s="hey"; print(s[0]); } }' >/tmp/hako_idx_out.txt 2>&1; then
   info "string index produced: $(cat /tmp/hako_idx_out.txt | tail -n1) (dev tolerance)"
diff --git a/tools/smokes/v2/profiles/quick/core/nyvm_wrapper_module_json_vm.sh b/tools/smokes/v2/profiles/quick/core/nyvm_wrapper_module_json_vm.sh
new file mode 100644
index 00000000..fe70401b
--- /dev/null
+++ b/tools/smokes/v2/profiles/quick/core/nyvm_wrapper_module_json_vm.sh
@@ -0,0 +1,49 @@
+#!/bin/bash
+# nyvm_wrapper_module_json_vm.sh — Ny wrapper bridge module-json canary (opt-in)
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+ROOT="$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel 2>/dev/null || cd "$SCRIPT_DIR/../../../../.." && pwd)"
+BIN="$ROOT/target/release/nyash"
+
+warn() { echo -e "[WARN] $*" >&2; }
+info() { echo -e "[INFO] $*" >&2; }
+pass() { echo -e "[PASS] $*" >&2; }
+skip() { echo -e "[SKIP] $*" >&2; exit 0; }
+fail() { echo -e "[FAIL] $*" >&2; exit 1; }
+
+# Opt-in guard
+if [ "${SMOKES_ENABLE_NYVM_WRAPPER:-0}" != "1" ]; then
+  skip "SMOKES_ENABLE_NYVM_WRAPPER!=1"
+fi
+
+if [ ! -x "$BIN" ]; then
+  (cd "$ROOT" && cargo build --release >/dev/null 2>&1) || fail "build failed"
+fi
+
+# Minimal MIR(JSON v0) module (return 7) — module-shaped
+JSON_FILE="/tmp/nyvm_wrapper_mod_$$.json"
+trap 'rm -f "$JSON_FILE"' EXIT
+cat > "$JSON_FILE" <<'J'
+{"kind":"MIR","schema_version":"1.0","functions":[{"name":"main","params":[],"blocks":[{"id":0,"instructions":[
+ {"op":"const","dst":1,"value":{"type":"i64","value":7}},
+ {"op":"ret","value":1}
+]}]}]}
+J
+
+# If wrapper path is not wired, skip rather than fail
+if ! strings "$BIN" 2>/dev/null | grep -q 'NyVmDispatcher'; then
+  skip "binary lacks NyVmDispatcher symbols (wrapper likely not wired)"
+fi
+
+# Run via Gate-C to Interpreter (control), then (optionally) wrapper would be tested when wired
+out=$("$BIN" --json-file "$JSON_FILE" 2>&1 || true)
+last=$(printf '%s\n' "$out" | awk '/^(✅|ResultType|Result:)/{next} NF{last=$0} END{print last}')
+if [ "$last" = "7" ]; then
+  pass "nyvm_wrapper_module_json_vm"
+else
+  echo "$out" >&2
+  fail "nyvm_wrapper_module_json_vm (expected 7, got '$last')"
+fi
+
diff --git a/tools/smokes/v2/profiles/quick/core/selfhost_stageb_binop_vm.sh b/tools/smokes/v2/profiles/quick/core/selfhost_stageb_binop_vm.sh
new file mode 100644
index 00000000..8bb962b3
--- /dev/null
+++ b/tools/smokes/v2/profiles/quick/core/selfhost_stageb_binop_vm.sh
@@ -0,0 +1,100 @@
+#!/bin/bash
+# selfhost_stageb_binop_vm.sh — Hako Stage‑B pipeline (ParserBox→FlowEntry) binop canary (opt‑in)
+
+set -uo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+if ROOT_GIT=$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel 2>/dev/null); then
+  ROOT="$ROOT_GIT"
+else
+  ROOT="$(cd "$SCRIPT_DIR/../../../../.." && pwd)"
+fi
+HAKO_BIN_DEFAULT="$ROOT/tools/bin/hako"
+HAKO_BIN="${HAKO_BIN:-$HAKO_BIN_DEFAULT}"
+
+warn() { echo -e "[WARN] $*" >&2; }
+info() { echo -e "[INFO] $*" >&2; }
+fail() { echo -e "[FAIL] $*" >&2; return 1; }
+pass() { echo -e "[PASS] $*" >&2; }
+
+require_hako() {
+  if [ "${SMOKES_ENABLE_STAGEB:-0}" != "1" ]; then
+    warn "SMOKES_ENABLE_STAGEB!=1; skipping Stage‑B canaries"
+    exit 0
+  fi
+  if [ ! -x "$HAKO_BIN" ]; then
+    warn "Hako binary not found: $HAKO_BIN (set HAKO_BIN to override)"
+    warn "Skipping Stage‑B binop canaries"
+    exit 0
+  fi
+}
+
+hako_compile_to_mir_stageb() {
+  local code="$1"
+  local hako_tmp="/tmp/hako_stageb_binop_$$.hako"
+  local json_out="/tmp/hako_stageb_binop_$$.mir.json"
+
+  printf "%s\n" "$code" > "$hako_tmp"
+
+  local raw="/tmp/hako_stageb_binop_raw_$$.txt"
+  NYASH_PARSER_ALLOW_SEMICOLON=1 \
+  NYASH_SYNTAX_SUGAR_LEVEL=full \
+  NYASH_ENABLE_ARRAY_LITERAL=1 \
+  HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
+  HAKO_PARSER_STAGE3=1 NYASH_PARSER_STAGE3=1 \
+  NYASH_VARMAP_GUARD_STRICT=0 NYASH_BLOCK_SCHEDULE_VERIFY=0 NYASH_PHI_VERIFY=0 \
+  NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
+  "$ROOT/target/release/nyash" --backend vm \
+    "$ROOT/lang/src/compiler/entry/compiler_stageb.hako" -- --source "$(cat "$hako_tmp")" > "$raw" 2>&1
+  awk '/"version":0/ && /"kind":"Program"/ {print; exit}' "$raw" > "$json_out"
+  rm -f "$raw"
+
+  local rc=$?
+  rm -f "$hako_tmp"
+  if [ $rc -ne 0 ] || [ ! -f "$json_out" ]; then
+    warn "Stage‑B compilation failed (rc=$rc)"
+    rm -f "$json_out"
+    return 1
+  fi
+  echo "$json_out"
+  return 0
+}
+
+run_mir_via_gate_c() {
+  local json_path="$1"
+  if [ ! -f "$json_path" ]; then warn "JSON file not found: $json_path"; return 1; fi
+  NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 NYASH_NYRT_SILENT_RESULT=1 \
+    out="$("$ROOT/target/release/nyash" --json-file "$json_path" 2>&1)"
+  printf '%s\n' "$out" | awk '/^(✅|ResultType|Result:)/{next} NF{last=$0} END{ if(last) print last }'
+  local rc=$?
+  rm -f "$json_path"
+  return $rc
+}
+
+run_hako() {
+  local code="$1"
+  local json_path
+  json_path=$(hako_compile_to_mir_stageb "$code") || return 1
+  run_mir_via_gate_c "$json_path"
+}
+
+check_exact() {
+  local expect="$1"; shift
+  local got="$1"; shift
+  local name="$1"; shift
+  if [ "$got" = "$expect" ]; then pass "$name"; return 0; fi
+  printf "Expected: %s\nActual:   %s\n" "$expect" "$got" >&2
+  fail "$name"
+}
+
+require_hako
+
+info "Stage‑B binop: 1+2"
+out=$(run_hako 'box Main { static method main() { print(1+2); } }')
+check_exact "3" "$out" "stageb_binop_add" || exit 1
+
+info "Stage‑B binop precedence: 1+2*3"
+out=$(run_hako 'box Main { static method main() { print(1+2*3); } }')
+check_exact "7" "$out" "stageb_binop_prec" || exit 1
+
+exit 0
diff --git a/tools/smokes/v2/profiles/quick/core/selfhost_stageb_if_vm.sh b/tools/smokes/v2/profiles/quick/core/selfhost_stageb_if_vm.sh
new file mode 100644
index 00000000..11f39a5c
--- /dev/null
+++ b/tools/smokes/v2/profiles/quick/core/selfhost_stageb_if_vm.sh
@@ -0,0 +1,90 @@
+#!/bin/bash
+# selfhost_stageb_if_vm.sh — Hako Stage‑B pipeline if-statement canary (opt‑in)
+
+set -uo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+if ROOT_GIT=$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel 2>/dev/null); then
+  ROOT="$ROOT_GIT"
+else
+  ROOT="$(cd "$SCRIPT_DIR/../../../../.." && pwd)"
+fi
+HAKO_BIN_DEFAULT="$ROOT/tools/bin/hako"
+HAKO_BIN="${HAKO_BIN:-$HAKO_BIN_DEFAULT}"
+
+warn() { echo -e "[WARN] $*" >&2; }
+info() { echo -e "[INFO] $*" >&2; }
+fail() { echo -e "[FAIL] $*" >&2; return 1; }
+pass() { echo -e "[PASS] $*" >&2; }
+
+require_hako() {
+  if [ "${SMOKES_ENABLE_STAGEB:-0}" != "1" ]; then
+    warn "SMOKES_ENABLE_STAGEB!=1; skipping Stage‑B canaries"
+    exit 0
+  fi
+  if [ ! -x "$HAKO_BIN" ]; then
+    warn "Hako binary not found: $HAKO_BIN (set HAKO_BIN to override)"
+    warn "Skipping Stage‑B if canaries"
+    exit 0
+  fi
+}
+
+hako_compile_to_mir_stageb() {
+  local code="$1"
+  local hako_tmp="/tmp/hako_stageb_if_$$.hako"
+  local json_out="/tmp/hako_stageb_if_$$.mir.json"
+  printf "%s\n" "$code" > "$hako_tmp"
+
+  local raw="/tmp/hako_stageb_if_raw_$$.txt"
+  NYASH_PARSER_ALLOW_SEMICOLON=1 NYASH_SYNTAX_SUGAR_LEVEL=full NYASH_ENABLE_ARRAY_LITERAL=1 \
+  HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
+  HAKO_PARSER_STAGE3=1 NYASH_PARSER_STAGE3=1 \
+  NYASH_VARMAP_GUARD_STRICT=0 NYASH_BLOCK_SCHEDULE_VERIFY=0 NYASH_PHI_VERIFY=0 \
+  NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
+  "$ROOT/target/release/nyash" --backend vm \
+    "$ROOT/lang/src/compiler/entry/compiler_stageb.hako" -- --source "$(cat "$hako_tmp")" > "$raw" 2>&1
+  awk '/"version":0/ && /"kind":"Program"/ {print; exit}' "$raw" > "$json_out"
+  rm -f "$raw" "$hako_tmp"
+
+  if [ ! -f "$json_out" ]; then
+    warn "Stage‑B compilation failed"
+    return 1
+  fi
+  echo "$json_out"
+}
+
+run_mir_via_gate_c() {
+  local json_path="$1"
+  NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 NYASH_NYRT_SILENT_RESULT=1 \
+    out="$("$ROOT/target/release/nyash" --json-file "$json_path" 2>&1)"
+  printf '%s\n' "$out" | awk '/^(✅|ResultType|Result:)/{next} NF{last=$0} END{ if(last) print last }'
+  rm -f "$json_path"
+}
+
+run_hako() {
+  local code="$1"
+  local json_path
+  json_path=$(hako_compile_to_mir_stageb "$code") || return 1
+  run_mir_via_gate_c "$json_path"
+}
+
+check_exact() {
+  local expect="$1"; shift
+  local got="$1"; shift
+  local name="$1"; shift
+  if [ "$got" = "$expect" ]; then pass "$name"; return 0; fi
+  printf "Expected: %s\nActual:   %s\n" "$expect" "$got" >&2
+  fail "$name"
+}
+
+require_hako
+
+info "Stage‑B if: true branch"
+out=$(run_hako 'box Main { static method main() { if(5>4){ print(1); } } }')
+check_exact "1" "$out" "stageb_if_true" || exit 1
+
+info "Stage‑B if: false branch"
+out=$(run_hako 'box Main { static method main() { if(4>5){ print(1); } } }')
+check_exact "" "$out" "stageb_if_false" || exit 1
+
+exit 0
diff --git a/tools/smokes/v2/profiles/quick/core/selfhost_stageb_index_vm.sh b/tools/smokes/v2/profiles/quick/core/selfhost_stageb_index_vm.sh
new file mode 100644
index 00000000..645c10e5
--- /dev/null
+++ b/tools/smokes/v2/profiles/quick/core/selfhost_stageb_index_vm.sh
@@ -0,0 +1,108 @@
+#!/bin/bash
+# selfhost_stageb_index_vm.sh — Hako Stage‑B pipeline index operator canary (opt‑in)
+
+set -uo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+if ROOT_GIT=$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel 2>/dev/null); then
+  ROOT="$ROOT_GIT"
+else
+  ROOT="$(cd "$SCRIPT_DIR/../../../../.." && pwd)"
+fi
+HAKO_BIN_DEFAULT="$ROOT/tools/bin/hako"
+HAKO_BIN="${HAKO_BIN:-$HAKO_BIN_DEFAULT}"
+
+warn() { echo -e "[WARN] $*" >&2; }
+info() { echo -e "[INFO] $*" >&2; }
+fail() { echo -e "[FAIL] $*" >&2; return 1; }
+pass() { echo -e "[PASS] $*" >&2; }
+
+require_hako() {
+  if [ "${SMOKES_ENABLE_STAGEB:-0}" != "1" ]; then
+    warn "SMOKES_ENABLE_STAGEB!=1; skipping Stage‑B canaries"
+    exit 0
+  fi
+  if [ ! -x "$HAKO_BIN" ]; then
+    warn "Hako binary not found: $HAKO_BIN (set HAKO_BIN to override)"
+    warn "Skipping Stage‑B index canaries"
+    exit 0
+  fi
+}
+
+hako_compile_to_mir_stageb() {
+  local code="$1"
+  local hako_tmp="/tmp/hako_stageb_idx_$$.hako"
+  local json_out="/tmp/hako_stageb_idx_$$.mir.json"
+  printf "%s\n" "$code" > "$hako_tmp"
+
+  local raw="/tmp/hako_stageb_idx_raw_$$.txt"
+  NYASH_PARSER_ALLOW_SEMICOLON=1 NYASH_SYNTAX_SUGAR_LEVEL=full NYASH_ENABLE_ARRAY_LITERAL=1 \
+  HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
+  HAKO_PARSER_STAGE3=1 NYASH_PARSER_STAGE3=1 \
+  NYASH_VARMAP_GUARD_STRICT=0 NYASH_BLOCK_SCHEDULE_VERIFY=0 NYASH_PHI_VERIFY=0 \
+  NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
+  "$ROOT/target/release/nyash" --backend vm \
+    "$ROOT/lang/src/compiler/entry/compiler_stageb.hako" -- --source "$(cat "$hako_tmp")" > "$raw" 2>&1
+  awk '/"version":0/ && /"kind":"Program"/ {print; exit}' "$raw" > "$json_out"
+  rm -f "$raw" "$hako_tmp"
+
+  if [ ! -f "$json_out" ]; then
+    warn "Stage‑B compilation failed"
+    return 1
+  fi
+  echo "$json_out"
+}
+
+run_mir_via_gate_c() {
+  local json_path="$1"
+  NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 NYASH_NYRT_SILENT_RESULT=1 \
+    out="$("$ROOT/target/release/nyash" --json-file "$json_path" 2>&1)"
+  printf '%s\n' "$out" | awk '/^(✅|ResultType|Result:)/{next} NF{last=$0} END{ if(last) print last }'
+  rm -f "$json_path"
+}
+
+run_hako() {
+  local code="$1"
+  local json_path
+  json_path=$(hako_compile_to_mir_stageb "$code") || return 1
+  run_mir_via_gate_c "$json_path"
+}
+
+check_exact() {
+  local expect="$1"; shift
+  local got="$1"; shift
+  local name="$1"; shift
+  if [ "$got" = "$expect" ]; then pass "$name"; return 0; fi
+  printf "Expected: %s\nActual:   %s\n" "$expect" "$got" >&2
+  fail "$name"
+}
+
+require_hako
+
+info "Stage‑B index: array read"
+out=$(run_hako 'box Main { static method main() { local a=[1,2,3]; print(a[0]); } }')
+check_exact "1" "$out" "stageb_index_array_read" || exit 1
+
+info "Stage‑B index: array write"
+out=$(run_hako 'box Main { static method main() { local a=[1,2]; a[1]=9; print(a[1]); } }')
+check_exact "9" "$out" "stageb_index_array_write" || exit 1
+
+info "Stage‑B index: map rw"
+out=$(run_hako 'box Main { static method main() { local m={"a":1}; m["b"]=7; print(m["b"]); } }')
+check_exact "7" "$out" "stageb_index_map_rw" || exit 1
+
+info "Stage‑B index: nested array"
+out=$(run_hako 'box Main { static method main() { local a=[[1,2],[3,4]]; print(a[1][0]); } }')
+check_exact "3" "$out" "stageb_index_nested_array" || exit 1
+
+info "Stage‑B index: missing map key diagnostic"
+if run_hako 'box Main { static method main() { local m={"a":1}; print(m["c"]); } }' >/tmp/hako_stageb_idx_diag.txt 2>&1; then
+  warn "expected failure but command succeeded"
+  cat /tmp/hako_stageb_idx_diag.txt >&2
+  fail "stageb_index_map_missing_diag" || exit 1
+else
+  pass "stageb_index_map_missing_diag"
+fi
+rm -f /tmp/hako_stageb_idx_diag.txt
+
+exit 0