diff --git a/Makefile b/Makefile
index 18c95429..39844711 100644
--- a/Makefile
+++ b/Makefile
@@ -4,40 +4,32 @@
 #   make layout    Rust layout（layout_file）
 #   make json      Go json 扩展（json-rwirext 可执行文件）
 #   make oldhero   Go 旧 runtime（kvlang-go，兼容保留，即将归档）
-#   make shm       链 kvspace-c 后端（SHM，默认，= all 的后端组件）
-#   make durable   链 kvspace_durable 后端（redis/fs/s3）
-#   make test      durable 后端全量 tutorial 回归
+#   make test      全量 tutorial 回归
 #   make install   一次性安装产物到最终态目录（.so→/usr/lib，可执行→/usr/bin，头→/usr/include/kvlang/）
-#   make all       全部（shm 后端 + json）
+#   make all       全部（runtime + term + layout + json）
 #   make clean     清理 bin/ 与各构建目录
-# 切换后端只需 make shm / make durable：runtime 经 cmake 重配、layout 经环境变量重建。
+# kvspace 后端由 libkvspace dispatch 前端按 DSN 运行时选择，不再编译期切换。
 
 BIN         := bin
-KVSPACE_LIB ?= kvspace-c
 
-.PHONY: all runtime term layout json oldhero shm durable test install clean
+.PHONY: all runtime term layout json oldhero test install clean
 
 all: runtime term layout json
 
-shm: runtime term layout
-
-durable: KVSPACE_LIB := kvspace_durable
-durable: runtime term layout
-
-test: durable
+test: all
 	python3 tutorial/test.py --no-build
 
 runtime:
-	cmake -S runtime -B build/runtime -DCMAKE_BUILD_TYPE=Release -DKVSPACE_LIB=$(KVSPACE_LIB)
+	cmake -S runtime -B build/runtime -DCMAKE_BUILD_TYPE=Release
 	cmake --build build/runtime --target kvlang_runtime -j
 
 term:
-	KVLANG_KVSPACE_LIB=$(KVSPACE_LIB) cargo build --release --manifest-path runtime-rwirext_example/rust/term/Cargo.toml
+	cargo build --release --manifest-path runtime-rwirext_example/rust/term/Cargo.toml
 	cp runtime-rwirext_example/rust/term/target/release/kvlang $(BIN)/kvlang
 
 layout:
-	KVLANG_KVSPACE_LIB=$(KVSPACE_LIB) cargo build --release --manifest-path layout/Cargo.toml --example layout_file
-	KVLANG_KVSPACE_LIB=$(KVSPACE_LIB) cargo build --release --manifest-path layout/Cargo.toml
+	cargo build --release --manifest-path layout/Cargo.toml --example layout_file
+	cargo build --release --manifest-path layout/Cargo.toml
 	cp layout/target/release/examples/layout_file $(BIN)/
 
 install:
@@ -48,11 +40,7 @@ install:
 	install -m 644 runtime/include/kvlang_runtime.h runtime/include/kvlang_rwirext.h /usr/include/kvlang/
 
 json:
-ifeq ($(KVSPACE_LIB),kvspace_durable)
-	cd runtime-rwirext_example/go/json && CGO_LDFLAGS="-L$(CURDIR)/../kvspace-durable/target/release -lkvspace_durable -Wl,--disable-new-dtags -Wl,-rpath,$(CURDIR)/../kvspace-durable/target/release" go build -o ../../../bin/json-rwirext ./cmd/
-else
-	cd runtime-rwirext_example/go/json && CGO_LDFLAGS="-L$(CURDIR)/../kvspace-c/build -lkvspace-c -Wl,--disable-new-dtags -Wl,-rpath,$(CURDIR)/../kvspace-c/build -Wl,-rpath,$(CURDIR)/../blockmalloc/build -Wl,-rpath,$(CURDIR)/../slotsboxmalloc/build" go build -o ../../../bin/json-rwirext ./cmd/
-endif
+	cd runtime-rwirext_example/go/json && CGO_LDFLAGS="-lkvspace" go build -o ../../../bin/json-rwirext ./cmd/
 
 oldhero:
 	cd oldhero && go build -ldflags="-s -w" -o ../bin/kvlang-go ./cmd/kvlang/
diff --git a/layout/build.rs b/layout/build.rs
index 1d63a1be..6c64dcb8 100644
--- a/layout/build.rs
+++ b/layout/build.rs
@@ -1,17 +1,5 @@
-// 链接 kvspace 动态库（cdylib）。布局侧只通过 extern "C" ABI 调用。
-// 依赖 .so 已由 ci/deps.sh 安装到 /usr/lib；默认 kvspace-durable，KVLANG_KVSPACE_LIB=kvspace-c 时用 SHM 版。
+// 链接 kvspace dispatch 前端（已安装 /usr/lib）。布局侧只通过 extern "C" ABI 调用，
+// 运行期由前端按 DSN 选后端（shm://→kvspace-c，其余→kvspace-durable）。
 fn main() {
-    println!("cargo:rerun-if-env-changed=KVLANG_KVSPACE_LIB");
-    let manifest = env!("CARGO_MANIFEST_DIR");
-    let array2d = format!("{manifest}/../.."); // array2d 工作区
-    let lib = std::env::var("KVLANG_KVSPACE_LIB").unwrap_or_else(|_| "kvspace_durable".into());
-    let dir = if lib == "kvspace_durable" {
-        format!("{array2d}/kvspace-durable/target/release")
-    } else {
-        format!("{array2d}/kvspace-c/build")
-    };
-    println!("cargo:rustc-link-search=native={dir}");
-    println!("cargo:rustc-link-lib=dylib={lib}");
-    println!("cargo:rustc-link-arg=-Wl,--disable-new-dtags");
-    println!("cargo:rustc-link-arg=-Wl,-rpath,{dir}");
+    println!("cargo:rustc-link-lib=dylib=kvspace");
 }
diff --git a/layout/src/lower.rs b/layout/src/lower.rs
index fedde228..2fb1bd5b 100644
--- a/layout/src/lower.rs
+++ b/layout/src/lower.rs
@@ -188,7 +188,6 @@ fn lower_for_with_cont(
     let idx_slot = lg.tmp();
     let cond_slot = lg.tmp();
     let len_slot = lg.tmp();
-    let keys_slot = lg.tmp();
     let key_slot = lg.tmp();
     let is_obj = s.iter.op == "obj"
         || s.iter.op == "map"
diff --git a/runtime-rwirext_example/rust/term/build.rs b/runtime-rwirext_example/rust/term/build.rs
index b6cc41b5..f504884b 100644
--- a/runtime-rwirext_example/rust/term/build.rs
+++ b/runtime-rwirext_example/rust/term/build.rs
@@ -1,34 +1,13 @@
-// 链接 C runtime（libkvlang_runtime.so）+ kvspace 后端（扩展宿主自连 kvspace）。
-// 产物统一在 kvlang/bin/，后端由 KVLANG_KVSPACE_LIB 选（对齐 runtime/layout），不 hardcode 绝对路径。
+// 链接 C runtime（libkvlang_runtime.so，bin/）+ kvspace dispatch 前端（已安装 /usr/lib）。
+// 产物统一在 kvlang/bin/；kvspace 后端由前端按 DSN 运行时选择。
 fn main() {
-    println!("cargo:rerun-if-env-changed=KVLANG_KVSPACE_LIB");
     let manifest = env!("CARGO_MANIFEST_DIR");
     let bin = format!("{manifest}/../../../bin"); // kvlang/bin
-    let array2d = format!("{manifest}/../../../.."); // array2d 工作区
 
     println!("cargo:rustc-link-search=native={bin}");
     println!("cargo:rustc-link-lib=dylib=kvlang_runtime");
-
-    let backend = std::env::var("KVLANG_KVSPACE_LIB").unwrap_or_else(|_| "kvspace-c".to_string());
-    let (lib, dirs) = if backend == "kvspace_durable" {
-        ("kvspace_durable", vec![format!("{array2d}/kvspace-durable/target/release")])
-    } else {
-        // kvspace-c 依赖 blockmalloc/slotsboxmalloc，需一并入 rpath（DT_RPATH 传递）
-        (
-            "kvspace-c",
-            vec![
-                format!("{array2d}/kvspace-c/build"),
-                format!("{array2d}/blockmalloc/build"),
-                format!("{array2d}/slotsboxmalloc/build"),
-            ],
-        )
-    };
-    println!("cargo:rustc-link-search=native={}", dirs[0]);
-    println!("cargo:rustc-link-lib=dylib={lib}");
+    println!("cargo:rustc-link-lib=dylib=kvspace");
 
     println!("cargo:rustc-link-arg=-Wl,--disable-new-dtags"); // rpath 转 DT_RPATH，传递解析 kvspace 的子依赖
     println!("cargo:rustc-link-arg=-Wl,-rpath,$ORIGIN");
-    for d in &dirs {
-        println!("cargo:rustc-link-arg=-Wl,-rpath,{d}");
-    }
 }
diff --git a/runtime/CMakeLists.txt b/runtime/CMakeLists.txt
index cc74888d..12523179 100644
--- a/runtime/CMakeLists.txt
+++ b/runtime/CMakeLists.txt
@@ -5,9 +5,6 @@ set(CMAKE_C_STANDARD 11)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
-# ── kvspace 后端（kvspace-c 或 kvspace_durable，均导出同一 C ABI）────
-set(KVSPACE_LIB "kvspace-c" CACHE STRING "kvspace 后端库：kvspace-c / kvspace_durable")
-
 # ── 输出统一到 bin/ ──────────────────────────────────────────────
 set(BIN_DIR "${CMAKE_SOURCE_DIR}/../bin")
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${BIN_DIR}")
@@ -20,12 +17,8 @@ add_library(kvlang_runtime SHARED
 target_include_directories(kvlang_runtime PUBLIC include src)
 target_compile_definitions(kvlang_runtime PRIVATE _GNU_SOURCE)
 
-if(KVSPACE_LIB STREQUAL "kvspace-c")
-    target_link_libraries(kvlang_runtime PRIVATE kvspace-c blockmalloc slotsboxmalloc)
-else()
-    target_link_libraries(kvlang_runtime PRIVATE kvspace_durable)
-endif()
-target_link_libraries(kvlang_runtime PRIVATE m pthread)
-# --export-dynamic 供 kvlang（term 扩展）找符号；--disable-new-dtags 使 rpath 转 DT_RPATH（传递），
-# 让 runtime → kvspace-c → blockmalloc/slotsboxmalloc 的传递依赖能被 runtime 的 rpath 找到。
+# 链接 kvspace dispatch 前端（已安装 /usr/lib），运行期按 DSN 选后端，编译期不再选后端。
+target_link_libraries(kvlang_runtime PRIVATE kvspace m pthread)
+
+# --export-dynamic 供 kvlang（term 扩展）找符号；--disable-new-dtags 使 rpath 转 DT_RPATH（传递）。
 set_target_properties(kvlang_runtime PROPERTIES LINK_FLAGS "-Wl,--export-dynamic -Wl,--disable-new-dtags")