diff --git a/scripts/build-all.mjs b/scripts/build-all.mjs
index 6d7b7fa0419..4b00df63f54 100644
--- a/scripts/build-all.mjs
+++ b/scripts/build-all.mjs
@@ -173,6 +173,16 @@ export const BUILD_ALL_PROFILE_STEP_ENV = {
       OPENCLAW_RUN_NODE_SKIP_DTS_BUILD: "1",
     },
   },
+  gatewayWatch: {
+    "runtime-postbuild": {
+      OPENCLAW_RUNTIME_POSTBUILD_STATIC_ASSETS: "0",
+    },
+  },
+  cliStartup: {
+    "runtime-postbuild": {
+      OPENCLAW_RUNTIME_POSTBUILD_STATIC_ASSETS: "0",
+    },
+  },
 };
 
 export function buildAllUsage() {
diff --git a/scripts/runtime-postbuild.mjs b/scripts/runtime-postbuild.mjs
index 7a43f923b65..7a977b38af8 100644
--- a/scripts/runtime-postbuild.mjs
+++ b/scripts/runtime-postbuild.mjs
@@ -453,6 +453,11 @@ export function writeLegacyCliExitCompatChunks(params = {}) {
   }
 }
 
+function shouldCopyStaticExtensionAssets(params) {
+  const env = params.env ?? process.env;
+  return env.OPENCLAW_RUNTIME_POSTBUILD_STATIC_ASSETS !== "0";
+}
+
 export function runRuntimePostBuild(params = {}) {
   const timingsEnabled = params.timings ?? process.env.OPENCLAW_RUNTIME_POSTBUILD_TIMINGS !== "0";
   const runPhase = (label, action) => {
@@ -471,6 +476,9 @@ export function runRuntimePostBuild(params = {}) {
   runPhase("official channel catalog", () => writeOfficialChannelCatalog(params));
   runPhase("bundled plugin runtime overlay", () => stageBundledPluginRuntime(params));
   runPhase("static extension assets", () => {
+    if (!shouldCopyStaticExtensionAssets(params)) {
+      return;
+    }
     const staticAssetParams = {
       rootDir: ROOT,
       ...params,
diff --git a/test/scripts/build-all.test.ts b/test/scripts/build-all.test.ts
index e9e9d81dc06..b63e9f7a0ba 100644
--- a/test/scripts/build-all.test.ts
+++ b/test/scripts/build-all.test.ts
@@ -180,9 +180,7 @@ describe("resolveBuildAllSteps", () => {
       help: true,
       profile: "cliStartup",
     });
-    expect(() => parseBuildAllArgs(["cliStartup", "--bogus"])).toThrow(
-      "unknown argument: --bogus",
-    );
+    expect(() => parseBuildAllArgs(["cliStartup", "--bogus"])).toThrow("unknown argument: --bogus");
     expect(() => parseBuildAllArgs(["wat"])).toThrow("Unknown build profile: wat");
   });
 
@@ -279,6 +277,28 @@ describe("resolveBuildAllSteps", () => {
     ]);
   });
 
+  it("skips generated static plugin assets for minimal backend-only profiles", () => {
+    for (const profile of ["gatewayWatch", "cliStartup"]) {
+      const runtimePostbuild = resolveBuildAllSteps(profile).find(
+        (step) => step.label === "runtime-postbuild",
+      );
+      if (!runtimePostbuild) {
+        throw new Error(`Missing ${profile} runtime-postbuild step`);
+      }
+
+      expect(BUILD_ALL_PROFILE_STEP_ENV[profile]["runtime-postbuild"]).toEqual({
+        OPENCLAW_RUNTIME_POSTBUILD_STATIC_ASSETS: "0",
+      });
+      expect(
+        resolveBuildAllStep(runtimePostbuild, {
+          env: { OPENCLAW_RUNTIME_POSTBUILD_STATIC_ASSETS: "1" },
+        }).options.env,
+      ).toMatchObject({
+        OPENCLAW_RUNTIME_POSTBUILD_STATIC_ASSETS: "0",
+      });
+    }
+  });
+
   it("writes the runtime postbuild stamp after the build stamp", () => {
     const labels = resolveBuildAllSteps("full").map((step) => step.label);
     expect(labels).toContain("runtime-postbuild");
diff --git a/test/scripts/runtime-postbuild.test.ts b/test/scripts/runtime-postbuild.test.ts
index 6257f026878..143a0420972 100644
--- a/test/scripts/runtime-postbuild.test.ts
+++ b/test/scripts/runtime-postbuild.test.ts
@@ -61,9 +61,7 @@ describe("runtime postbuild static assets", () => {
       "dist/extensions/diffs-language-pack/assets/viewer-runtime.js",
       "dist/extensions/diffs/assets/viewer-runtime.js",
     ]);
-    expect(payload.sources).toContain(
-      "extensions/diffs-language-pack/assets/viewer-runtime.js",
-    );
+    expect(payload.sources).toContain("extensions/diffs-language-pack/assets/viewer-runtime.js");
     expect(payload.sources).toContain("extensions/diffs/assets/viewer-runtime.js");
   });
 
@@ -208,6 +206,45 @@ describe("runtime postbuild static assets", () => {
     await expect(fs.readFile(runtimeAsset, "utf8")).resolves.toBe("console.log('viewer');\n");
   });
 
+  it("can skip static asset copies for minimal runtime builds", async () => {
+    const rootDir = createTempDir("openclaw-runtime-postbuild-");
+    const warn = vi.fn();
+    const output = "assets/viewer-runtime.js";
+
+    await fs.mkdir(path.join(rootDir, "src", "plugin-sdk"), { recursive: true });
+    await fs.writeFile(
+      path.join(rootDir, "src", "plugin-sdk", "root-alias.cjs"),
+      "module.exports = {};\n",
+      "utf8",
+    );
+    await fs.mkdir(path.join(rootDir, "extensions", "diffs"), { recursive: true });
+    await fs.writeFile(
+      path.join(rootDir, "extensions", "diffs", "package.json"),
+      JSON.stringify({
+        name: "@openclaw/diffs",
+        openclaw: {
+          extensions: ["./index.ts"],
+          build: {
+            staticAssets: [{ source: `./${output}`, output }],
+          },
+        },
+      }),
+      "utf8",
+    );
+
+    runRuntimePostBuild({
+      cwd: rootDir,
+      repoRoot: rootDir,
+      rootDir,
+      env: { OPENCLAW_RUNTIME_POSTBUILD_STATIC_ASSETS: "0" },
+      timings: false,
+      warn,
+    });
+
+    expect(warn).not.toHaveBeenCalled();
+    await expectPathMissing(path.join(rootDir, "dist", "extensions", "diffs", output));
+  });
+
   it("skips runtime overlay asset copies when the runtime extension root is absent", async () => {
     const rootDir = createTempDir("openclaw-runtime-postbuild-");
     await fs.mkdir(path.join(rootDir, "extensions", "demo", "assets"), { recursive: true });