diff --git a/tools/dev/enable_mirbuilder_dev_env.sh b/tools/dev/enable_mirbuilder_dev_env.sh
index 23e93d6e..b8c16440 100644
--- a/tools/dev/enable_mirbuilder_dev_env.sh
+++ b/tools/dev/enable_mirbuilder_dev_env.sh
@@ -29,8 +29,8 @@ export NYASH_JSON_SCHEMA_V1=${NYASH_JSON_SCHEMA_V1:-1}
 export NYASH_MIR_UNIFIED_CALL=${NYASH_MIR_UNIFIED_CALL:-1}
 
 # Parser: Stage-3 ON, allow semicolons
-export NYASH_PARSER_STAGE3=${NYASH_PARSER_STAGE3:-1}
-export HAKO_PARSER_STAGE3=${HAKO_PARSER_STAGE3:-1}
+export NYASH_FEATURES=${NYASH_PARSER_STAGE3:-1}
+export NYASH_FEATURES=${HAKO_PARSER_STAGE3:-1}
 export NYASH_PARSER_ALLOW_SEMICOLON=${NYASH_PARSER_ALLOW_SEMICOLON:-1}
 
 if [[ "${1:-}" != "quiet" ]]; then
diff --git a/tools/dev/enable_phase216_env.sh b/tools/dev/enable_phase216_env.sh
index 161a840f..d9a59e57 100644
--- a/tools/dev/enable_phase216_env.sh
+++ b/tools/dev/enable_phase216_env.sh
@@ -5,8 +5,8 @@ set -euo pipefail
 export HAKO_SELFHOST_BUILDER_FIRST=1
 export NYASH_USE_NY_COMPILER=0
 export HAKO_DISABLE_NY_COMPILER=1
-export NYASH_PARSER_STAGE3=1
-export HAKO_PARSER_STAGE3=1
+export NYASH_FEATURES=stage3
+export NYASH_FEATURES=stage3
 export NYASH_PARSER_ALLOW_SEMICOLON=1
 export NYASH_ENABLE_USING=1
 export HAKO_ENABLE_USING=1
diff --git a/tools/dev/hako_debug_run.sh b/tools/dev/hako_debug_run.sh
index 08603d15..66c6a3b8 100644
--- a/tools/dev/hako_debug_run.sh
+++ b/tools/dev/hako_debug_run.sh
@@ -63,8 +63,8 @@ if [[ "$MODE_CODE" -eq 0 && -z "$FILE" ]]; then
 fi
 
 # Base env (Stage-3 + tolerance)
-export NYASH_PARSER_STAGE3=1
-export HAKO_PARSER_STAGE3=1
+export NYASH_FEATURES=stage3
+export NYASH_FEATURES=stage3
 export NYASH_PARSER_ALLOW_SEMICOLON=1
 export NYASH_ENTRY_ALLOW_TOPLEVEL_MAIN=1
 
diff --git a/tools/dev/phase216_chain_canary.sh b/tools/dev/phase216_chain_canary.sh
index 4daf4c33..29dabe8d 100644
--- a/tools/dev/phase216_chain_canary.sh
+++ b/tools/dev/phase216_chain_canary.sh
@@ -23,7 +23,7 @@ OUT_EXE=$(mktemp --suffix .exe)
 # Emit MIR(JSON)
 HAKO_SELFHOST_BUILDER_FIRST=1 \
 NYASH_USE_NY_COMPILER=0 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
   bash "$ROOT/tools/hakorune_emit_mir.sh" "$TMP_SRC" "$TMP_JSON" >/dev/null
 
diff --git a/tools/dev/phase216_chain_canary_binop.sh b/tools/dev/phase216_chain_canary_binop.sh
index 4b47de2a..14ad1c68 100644
--- a/tools/dev/phase216_chain_canary_binop.sh
+++ b/tools/dev/phase216_chain_canary_binop.sh
@@ -14,7 +14,7 @@ OUT_EXE=$(mktemp --suffix .exe)
 
 HAKO_SELFHOST_BUILDER_FIRST=1 \
 NYASH_USE_NY_COMPILER=0 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
   bash "$ROOT/tools/hakorune_emit_mir.sh" "$TMP_SRC" "$TMP_JSON" >/dev/null
 
diff --git a/tools/dev/phase216_chain_canary_call.sh b/tools/dev/phase216_chain_canary_call.sh
index 6558b4e8..9c55746c 100644
--- a/tools/dev/phase216_chain_canary_call.sh
+++ b/tools/dev/phase216_chain_canary_call.sh
@@ -23,7 +23,7 @@ HAKO_STAGEB_FUNC_SCAN=1 \
 HAKO_MIR_BUILDER_FUNCS=1 \
 HAKO_MIR_BUILDER_CALL_RESOLVE=1 \
 NYASH_USE_NY_COMPILER=0 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
   bash "$ROOT/tools/hakorune_emit_mir.sh" "$TMP_SRC" "$TMP_JSON" >/dev/null
 
diff --git a/tools/dev/phase216_chain_canary_return.sh b/tools/dev/phase216_chain_canary_return.sh
index 000c607c..706815f2 100644
--- a/tools/dev/phase216_chain_canary_return.sh
+++ b/tools/dev/phase216_chain_canary_return.sh
@@ -14,7 +14,7 @@ OUT_EXE=$(mktemp --suffix .exe)
 
 HAKO_SELFHOST_BUILDER_FIRST=1 \
 NYASH_USE_NY_COMPILER=0 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
   bash "$ROOT/tools/hakorune_emit_mir.sh" "$TMP_SRC" "$TMP_JSON" >/dev/null
 
diff --git a/tools/dev/phase217_methodize_canary.sh b/tools/dev/phase217_methodize_canary.sh
index f56f7eda..141701f4 100644
--- a/tools/dev/phase217_methodize_canary.sh
+++ b/tools/dev/phase217_methodize_canary.sh
@@ -21,7 +21,7 @@ HAKO_MIR_BUILDER_FUNCS=1 \
 HAKO_MIR_BUILDER_CALL_RESOLVE=1 \
 HAKO_MIR_BUILDER_METHODIZE=1 \
 NYASH_USE_NY_COMPILER=0 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
   bash "$ROOT/tools/hakorune_emit_mir.sh" "$TMP_SRC" "$TMP_JSON" >/dev/null
 
diff --git a/tools/dev/stageb_loop_json_canary.sh b/tools/dev/stageb_loop_json_canary.sh
index 4533eec5..4c75e754 100644
--- a/tools/dev/stageb_loop_json_canary.sh
+++ b/tools/dev/stageb_loop_json_canary.sh
@@ -23,7 +23,7 @@ NYASH_BIN=${NYASH_BIN:-"$ROOT/target/release/hakorune"}
 
 # Emit Program(JSON v0) via Stage‑B
 OUT=$(NYASH_JSON_ONLY=1 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-      NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+      NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
       NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
       "$NYASH_BIN" --backend vm lang/src/compiler/entry/compiler_stageb.hako -- --source "$(cat "$TMP_SRC")" 2>/dev/null | awk '/^{/,/^}$/')
 
diff --git a/tools/dev_stageb.sh b/tools/dev_stageb.sh
index 00608f88..eb78826e 100644
--- a/tools/dev_stageb.sh
+++ b/tools/dev_stageb.sh
@@ -35,7 +35,7 @@ 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_FEATURES=stage3 NYASH_FEATURES=stage3 \
 NYASH_VARMAP_GUARD_STRICT=0 NYASH_BLOCK_SCHEDULE_VERIFY=0 NYASH_PHI_VERIFY=0 \
 NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
 "$BIN" --backend vm "$ROOT/lang/src/compiler/entry/compiler.hako" -- --stage-b --source "$CODE" >"$RAW" 2>&1 || true
diff --git a/tools/dump_stageb_min_mir.sh b/tools/dump_stageb_min_mir.sh
index 413d2eef..acdc24f0 100644
--- a/tools/dump_stageb_min_mir.sh
+++ b/tools/dump_stageb_min_mir.sh
@@ -33,7 +33,7 @@ echo "[stageb/dump] emitting Program(JSON v0) → $OUT_PROGRAM"
 NYASH_JSON_ONLY=1 \
 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
 HAKO_STAGEB_FUNC_SCAN=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 \
 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
 HAKO_LOOPSSA_EXIT_PHI="${HAKO_LOOPSSA_EXIT_PHI:-0}" \
diff --git a/tools/hako_check/dot_edges_smoke.sh b/tools/hako_check/dot_edges_smoke.sh
index 03f753a0..e66b7f59 100644
--- a/tools/hako_check/dot_edges_smoke.sh
+++ b/tools/hako_check/dot_edges_smoke.sh
@@ -25,7 +25,7 @@ HK
 export LD_LIBRARY_PATH="${ROOT}/target/release:${LD_LIBRARY_PATH:-}"
 OUT=$(
   NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-  NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 \
+  NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 \
   NYASH_DISABLE_PLUGINS=1 NYASH_BOX_FACTORY_POLICY=builtin_first \
   "$BIN" --backend vm "$ROOT/tools/hako_check/cli.hako" -- --format dot --source-file "$TMP_HAKO" "$(sed 's/\r$//' "$TMP_HAKO")"
 )
diff --git a/tools/hakorune_emit_mir.sh b/tools/hakorune_emit_mir.sh
index 5431de65..68da7407 100644
--- a/tools/hakorune_emit_mir.sh
+++ b/tools/hakorune_emit_mir.sh
@@ -348,7 +348,7 @@ diagnose_stageb_failure() {
   if printf '%s\n' "$raw" | grep -q "Undefined variable: local"; then
     echo "[stageb/diagnose] Undefined variable: local" >&2
     echo "[stageb/hint] 'local' は Stage‑3 キーワードだよ。" >&2
-    echo "[stageb/hint] NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 を有効にするか、tools/hakorune_emit_mir.sh 経由で実行してね。" >&2
+    echo "[stageb/hint] NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 を有効にするか、tools/hakorune_emit_mir.sh 経由で実行してね。" >&2
   fi
   # Generic parse error
   if printf '%s\n' "$raw" | grep -q "Parse error"; then
@@ -395,7 +395,7 @@ fi
 PROG_JSON_RAW=$(cd "$ROOT" && \
                 NYASH_JSON_ONLY=${NYASH_JSON_ONLY:-1} NYASH_DISABLE_NY_COMPILER=${NYASH_DISABLE_NY_COMPILER:-1} HAKO_DISABLE_NY_COMPILER=${HAKO_DISABLE_NY_COMPILER:-1} \
                 HAKO_STAGEB_FUNC_SCAN="${HAKO_STAGEB_FUNC_SCAN:-1}" \
-                NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+                NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
                 NYASH_ENABLE_USING=${NYASH_ENABLE_USING:-1} HAKO_ENABLE_USING=${HAKO_ENABLE_USING:-1} \
                 "$NYASH_BIN" --backend vm "$stageb_target" -- "${stageb_extra[@]}" --source "$(cat "$CODE_TMP")" 2>&1)
 rc=$?
@@ -588,7 +588,7 @@ HCODE
   set +e
   (cd "$ROOT" && \
     NYASH_DISABLE_PLUGINS=1 NYASH_FILEBOX_MODE="core-ro" \
-    NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+    NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
     HAKO_BUILDER_PROGRAM_JSON="$prog_json" \
     "$NYASH_BIN" --backend vm "$tmp_hako" 2>&1 | tee "$tmp_stdout" >/dev/null)
   local rc=$?
@@ -630,7 +630,7 @@ HAKO
     # AotPrep(run_json) は自己ホストVMで JSON を1回走査するだけなので、既定ではステップ上限なし（0）で実行する。
     # 必要に応じて HAKO_VM_MAX_STEPS / NYASH_VM_MAX_STEPS を明示上書き可能。
     HAKO_VM_MAX_STEPS="${HAKO_VM_MAX_STEPS:-0}" NYASH_VM_MAX_STEPS="${NYASH_VM_MAX_STEPS:-0}" \
-    NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+    NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
     NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 HAKO_USING_RESOLVER_FIRST=1 \
     NYASH_AOT_COLLECTIONS_HOT=${NYASH_AOT_COLLECTIONS_HOT:-0} NYASH_LLVM_FAST=${NYASH_LLVM_FAST:-0} NYASH_MIR_LOOP_HOIST=${NYASH_MIR_LOOP_HOIST:-0} NYASH_AOT_MAP_KEY_MODE=${NYASH_AOT_MAP_KEY_MODE:-auto} \
     NYASH_AOT_NUMERIC_CORE=${NYASH_AOT_NUMERIC_CORE:-0} NYASH_AOT_NUMERIC_CORE_TRACE=${NYASH_AOT_NUMERIC_CORE_TRACE:-0} \
@@ -768,7 +768,7 @@ HCODE
     HAKO_MIR_BUILDER_DEBUG="${HAKO_MIR_BUILDER_DEBUG:-}" \
     NYASH_DISABLE_PLUGINS="${NYASH_DISABLE_PLUGINS:-0}" NYASH_FILEBOX_MODE="core-ro" HAKO_PROVIDER_POLICY="safe-core-first" \
     NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 HAKO_USING_RESOLVER_FIRST=1 \
-    NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+    NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
     NYASH_USE_NY_COMPILER=0 HAKO_USE_NY_COMPILER=0 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
     NYASH_MACRO_DISABLE=1 HAKO_MACRO_DISABLE=1 \
     # Builder 実行時は Step budget を既定で「無制限（0）」にしておく（大きな Program(JSON) でも上限で落とさない）。
@@ -892,7 +892,7 @@ HCODE
   set +e
   (cd "$ROOT" && \
     NYASH_DISABLE_PLUGINS="${NYASH_DISABLE_PLUGINS:-0}" NYASH_FILEBOX_MODE="core-ro" \
-    NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+    NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
     HAKO_BUILDER_PROGRAM_JSON="$prog_json" \
     NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 HAKO_USING_RESOLVER_FIRST=1 \
     "$NYASH_BIN" --backend vm "$tmp_hako" 2>"$tmp_stderr" | tee "$tmp_stdout" >/dev/null)
@@ -958,7 +958,7 @@ EOF
     set +e
     HAKO_PREP_INPUT="$(cat "$out_path")" \
     NYASH_FILEBOX_MODE=core-ro \
-    NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+    NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
     NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 HAKO_USING_RESOLVER_FIRST=1 \
     NYASH_AOT_COLLECTIONS_HOT=${NYASH_AOT_COLLECTIONS_HOT:-0} NYASH_LLVM_FAST=${NYASH_LLVM_FAST:-0} NYASH_MIR_LOOP_HOIST=${NYASH_MIR_LOOP_HOIST:-0} NYASH_AOT_MAP_KEY_MODE=${NYASH_AOT_MAP_KEY_MODE:-auto} \
     NYASH_AOT_NUMERIC_CORE=${NYASH_AOT_NUMERIC_CORE:-0} NYASH_AOT_NUMERIC_CORE_TRACE=${NYASH_AOT_NUMERIC_CORE_TRACE:-0} \
diff --git a/tools/joinir_ab_test.sh b/tools/joinir_ab_test.sh
index a708aef7..fb3b16a4 100644
--- a/tools/joinir_ab_test.sh
+++ b/tools/joinir_ab_test.sh
@@ -22,8 +22,8 @@ echo ""
 # Route A: Traditional if_phi
 echo "=== Route A (if_phi) ==="
 HAKO_JOINIR_IF_SELECT=0 \
-NYASH_PARSER_STAGE3=1 \
-HAKO_PARSER_STAGE3=1 \
+NYASH_FEATURES=stage3 \
+NYASH_FEATURES=stage3 \
     ./target/release/hakorune "$test_case" \
     > /tmp/route_a.out 2>&1
 route_a_rc=$?
@@ -35,8 +35,8 @@ echo "=== Route B (JoinIR) ==="
 HAKO_JOINIR_IF_SELECT=1 \
 HAKO_JOINIR_STAGE1=1 \
 HAKO_JOINIR_DEBUG=1 \
-NYASH_PARSER_STAGE3=1 \
-HAKO_PARSER_STAGE3=1 \
+NYASH_FEATURES=stage3 \
+NYASH_FEATURES=stage3 \
     ./target/release/hakorune "$test_case" \
     > /tmp/route_b.out 2>&1
 route_b_rc=$?
diff --git a/tools/ny_selfhost_inline.sh b/tools/ny_selfhost_inline.sh
index 8b37a490..54b5d312 100644
--- a/tools/ny_selfhost_inline.sh
+++ b/tools/ny_selfhost_inline.sh
@@ -13,7 +13,7 @@
 #     - nyash_binary: optional path to hakorune/nyash binary (default: target/release/hakorune or nyash).
 #
 # Notes:
-#   - Forces Stage-3 parser ON for the child (NYASH_PARSER_STAGE3=1/HAKO_PARSER_STAGE3=1).
+#   - Forces Stage-3 parser ON for the child (NYASH_FEATURES=stage3/NYASH_FEATURES=stage3).
 #   - Enables using resolver with file-based using (dev profile) so that lang.compiler.* modules can be found.
 #   - Does NOT perform Stage-0 prelude text merge or preexpand_at_local; it feeds the raw source to ParserBox.
 
@@ -79,7 +79,7 @@ SRC_CONTENT="$(cat "$SRC")"
 
 NYASH_INLINE_SRC="$SRC_CONTENT" \
 NYASH_JSON_ONLY=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
 NYASH_ALLOW_USING_FILE=1 HAKO_ALLOW_USING_FILE=1 \
 "$BIN" --backend vm "$HARNESS"
diff --git a/tools/perf/bench_compare_c_vs_hako.sh b/tools/perf/bench_compare_c_vs_hako.sh
index 0d002f87..de5d6a13 100644
--- a/tools/perf/bench_compare_c_vs_hako.sh
+++ b/tools/perf/bench_compare_c_vs_hako.sh
@@ -83,8 +83,8 @@ C_MED=$(printf "%s\n" "${C_SERIES}" | median_ms)
 # Minimal env for fast VM bring-up (bench profile)
 # - Disable dynamic plugins and nyash.toml env injection to avoid startup scans
 HAKO_ENV=(
-  NYASH_PARSER_STAGE3=1
-  HAKO_PARSER_STAGE3=1
+  NYASH_FEATURES=stage3
+  NYASH_FEATURES=stage3
   NYASH_PARSER_ALLOW_SEMICOLON=1
   NYASH_DISABLE_PLUGINS=1
   NYASH_SKIP_TOML_ENV=1
diff --git a/tools/perf/record_baselines.sh b/tools/perf/record_baselines.sh
index 240293f8..8cfa765f 100644
--- a/tools/perf/record_baselines.sh
+++ b/tools/perf/record_baselines.sh
@@ -64,7 +64,7 @@ record_one() {
   local hako_bin="${TARGET_DIR}/release/hakorune"
   local hako_prog="${ROOT_DIR}/benchmarks/bench_${key}.hako"
   if [[ -x "${hako_bin}" && -f "${hako_prog}" ]]; then
-    local -a HAKO_ENV=(NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1)
+    local -a HAKO_ENV=(NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1)
     local hako_series; hako_series=$(collect_series "${WARMUP}" "${REPEAT}" env "${HAKO_ENV[@]}" timeout 20s "${hako_bin}" --backend vm "${hako_prog}")
     ny_vm_ms=$(printf "%s\n" "${hako_series}" | median_ms)
     # Optional subtract: measure minimal VM startup (ret0)
diff --git a/tools/selfhost/gen_v0_from_selfhost_pipeline_min.sh b/tools/selfhost/gen_v0_from_selfhost_pipeline_min.sh
index baeb1327..82d7f0c0 100644
--- a/tools/selfhost/gen_v0_from_selfhost_pipeline_min.sh
+++ b/tools/selfhost/gen_v0_from_selfhost_pipeline_min.sh
@@ -18,6 +18,6 @@ HCODE
 
 NYASH_USING_PROFILE=dev NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
 
diff --git a/tools/selfhost/gen_v1_from_builder.sh b/tools/selfhost/gen_v1_from_builder.sh
index 9b2c274e..34828d7b 100644
--- a/tools/selfhost/gen_v1_from_builder.sh
+++ b/tools/selfhost/gen_v1_from_builder.sh
@@ -16,5 +16,5 @@ HCODE
 )
 
 NYASH_USING_AST=1 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_JSON_ONLY=1 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
diff --git a/tools/selfhost/gen_v1_from_builder_branch_ret_44.sh b/tools/selfhost/gen_v1_from_builder_branch_ret_44.sh
index de24f09f..d36ccccb 100644
--- a/tools/selfhost/gen_v1_from_builder_branch_ret_44.sh
+++ b/tools/selfhost/gen_v1_from_builder_branch_ret_44.sh
@@ -19,6 +19,6 @@ HCODE
 )
 
 NYASH_USING_AST=1 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
 
diff --git a/tools/selfhost/gen_v1_from_builder_compare_cfg.sh b/tools/selfhost/gen_v1_from_builder_compare_cfg.sh
index 19e7b413..1c1094f2 100644
--- a/tools/selfhost/gen_v1_from_builder_compare_cfg.sh
+++ b/tools/selfhost/gen_v1_from_builder_compare_cfg.sh
@@ -17,6 +17,6 @@ HCODE
 )
 
 NYASH_USING_AST=1 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
 
diff --git a/tools/selfhost/gen_v1_from_builder_compare_ret.sh b/tools/selfhost/gen_v1_from_builder_compare_ret.sh
index 4af65c96..c9609630 100644
--- a/tools/selfhost/gen_v1_from_builder_compare_ret.sh
+++ b/tools/selfhost/gen_v1_from_builder_compare_ret.sh
@@ -17,6 +17,6 @@ HCODE
 )
 
 NYASH_USING_AST=1 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
 
diff --git a/tools/selfhost/gen_v1_from_provider.sh b/tools/selfhost/gen_v1_from_provider.sh
index c08473d2..8169761d 100644
--- a/tools/selfhost/gen_v1_from_provider.sh
+++ b/tools/selfhost/gen_v1_from_provider.sh
@@ -33,5 +33,5 @@ HCODE
 NYASH_PROGRAM_JSON="$prog_json" \
 NYASH_JSON_SCHEMA_V1=1 \
 NYASH_USING_AST=1 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
diff --git a/tools/selfhost/gen_v1_from_provider_min.sh b/tools/selfhost/gen_v1_from_provider_min.sh
index 2aa1dff3..3947b114 100644
--- a/tools/selfhost/gen_v1_from_provider_min.sh
+++ b/tools/selfhost/gen_v1_from_provider_min.sh
@@ -20,6 +20,6 @@ HCODE
 NYASH_PROGRAM_JSON="$prog_json" \
 NYASH_JSON_SCHEMA_V1=1 \
 NYASH_USING_AST=1 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
 
diff --git a/tools/selfhost/gen_v1_from_selfhost_pipeline_min.sh b/tools/selfhost/gen_v1_from_selfhost_pipeline_min.sh
index d2d13a10..4fd182dd 100644
--- a/tools/selfhost/gen_v1_from_selfhost_pipeline_min.sh
+++ b/tools/selfhost/gen_v1_from_selfhost_pipeline_min.sh
@@ -18,5 +18,5 @@ HCODE
 
 NYASH_USING_PROFILE=dev NYASH_ENABLE_USING=1 HAKO_ENABLE_USING=1 \
 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_JSON_ONLY=1 run_nyash_vm -c "$code" 2>/dev/null | tr -d '\r'
diff --git a/tools/selfhost/gen_v1_min.sh b/tools/selfhost/gen_v1_min.sh
index 04d8e2bc..1c95b04a 100644
--- a/tools/selfhost/gen_v1_min.sh
+++ b/tools/selfhost/gen_v1_min.sh
@@ -38,7 +38,7 @@ sed -i '/using selfhost\.shared\.common\.entry_point_base/d' "$pref" 2>/dev/null
 
 # できるだけ静かに実行して JSON のみを出力
 NYASH_ROOT="$ROOT" NYASH_ENTRY_ALLOW_TOPLEVEL_MAIN=1 \
-NYASH_PARSER_STAGE3=1 HAKO_PARSER_STAGE3=1 NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_FEATURES=stage3 NYASH_FEATURES=stage3 NYASH_PARSER_ALLOW_SEMICOLON=1 \
 NYASH_DISABLE_NY_COMPILER=1 HAKO_DISABLE_NY_COMPILER=1 NYASH_USING_AST=0 \
 "$NYASH_BIN" --backend vm "$pref" 2>/dev/null | tr -d '\r'
 rm -f "$tmp" "$pref" 2>/dev/null || true
diff --git a/tools/selfhost_smoke.sh b/tools/selfhost_smoke.sh
index 1803248e..57c7c582 100644
--- a/tools/selfhost_smoke.sh
+++ b/tools/selfhost_smoke.sh
@@ -17,7 +17,7 @@ echo "[selfhost-smoke] Step 1: Emit JSON via selfhost compiler (lang/, optional)
 OUT_JSON="/tmp/nyash_selfhost_out.json"
 set -x
 # Use lang side entry (Stage‑B). Emission is optional; failure does not fail the smoke.
-if NYASH_ENABLE_USING=1 NYASH_ALLOW_USING_FILE=1 NYASH_USING_AST=1 NYASH_PARSER_STAGE3=1 \
+if NYASH_ENABLE_USING=1 NYASH_ALLOW_USING_FILE=1 NYASH_USING_AST=1 NYASH_FEATURES=stage3 \
    "${NY_BIN}" --backend vm "${ROOT_DIR}/lang/src/compiler/entry/compiler_stageb.hako" -- --source 'box Main { static method main() { return 0 } }' > "${OUT_JSON}" 2>/dev/null; then
   :
 else