diff --git a/scripts/tsdown-build.mjs b/scripts/tsdown-build.mjs
index 4767ade3bff..0e11c439e44 100644
--- a/scripts/tsdown-build.mjs
+++ b/scripts/tsdown-build.mjs
@@ -16,6 +16,7 @@ const extraArgs = process.argv.slice(2);
 const INEFFECTIVE_DYNAMIC_IMPORT_RE = /\[INEFFECTIVE_DYNAMIC_IMPORT\]/;
 const UNRESOLVED_IMPORT_RE = /\[UNRESOLVED_IMPORT\]/;
 const ANSI_ESCAPE_RE = new RegExp(String.raw`\u001B\[[0-9;]*m`, "g");
+const HASHED_ROOT_JS_RE = /^(?<base>.+)-[A-Za-z0-9_-]+\.js$/u;
 
 function removeDistPluginNodeModulesSymlinks(rootDir) {
   const extensionsDir = path.join(rootDir, "extensions");
@@ -47,6 +48,34 @@ function pruneStaleRuntimeSymlinks() {
   removeDistPluginNodeModulesSymlinks(path.join(cwd, "dist-runtime"));
 }
 
+export function pruneStaleRootChunkFiles(params = {}) {
+  const cwd = params.cwd ?? process.cwd();
+  const fsImpl = params.fs ?? fs;
+  const roots = [path.join(cwd, "dist"), path.join(cwd, "dist-runtime")];
+  for (const root of roots) {
+    let entries = [];
+    try {
+      entries = fsImpl.readdirSync(root, { withFileTypes: true });
+    } catch {
+      continue;
+    }
+
+    for (const entry of entries) {
+      if (!entry.isFile()) {
+        continue;
+      }
+      if (!HASHED_ROOT_JS_RE.test(entry.name)) {
+        continue;
+      }
+      try {
+        fsImpl.rmSync(path.join(root, entry.name), { force: true });
+      } catch {
+        // Best-effort cleanup. The subsequent build will overwrite any stragglers.
+      }
+    }
+  }
+}
+
 export function pruneSourceCheckoutBundledPluginNodeModules(params = {}) {
   const cwd = params.cwd ?? process.cwd();
   const logger = params.logger ?? console;
@@ -116,6 +145,7 @@ function isMainModule() {
 if (isMainModule()) {
   pruneSourceCheckoutBundledPluginNodeModules();
   pruneStaleRuntimeSymlinks();
+  pruneStaleRootChunkFiles();
   const invocation = resolveTsdownBuildInvocation();
   const result = spawnSync(invocation.command, invocation.args, invocation.options);
 
diff --git a/test/scripts/tsdown-build.test.ts b/test/scripts/tsdown-build.test.ts
index 430230588a5..fe0f0ab5e6d 100644
--- a/test/scripts/tsdown-build.test.ts
+++ b/test/scripts/tsdown-build.test.ts
@@ -1,9 +1,15 @@
 import fs from "node:fs";
+import fsPromises from "node:fs/promises";
+import path from "node:path";
 import { describe, expect, it, vi } from "vitest";
 import {
   pruneSourceCheckoutBundledPluginNodeModules,
+  pruneStaleRootChunkFiles,
   resolveTsdownBuildInvocation,
 } from "../../scripts/tsdown-build.mjs";
+import { createScriptTestHarness } from "./test-helpers.js";
+
+const { createTempDir } = createScriptTestHarness();
 
 describe("resolveTsdownBuildInvocation", () => {
   it("routes Windows tsdown builds through the pnpm runner instead of shell=true", () => {
@@ -56,4 +62,44 @@ describe("resolveTsdownBuildInvocation", () => {
     warn.mockRestore();
     rmSync.mockRestore();
   });
+
+  it("prunes stale hashed root chunk files but keeps stable aliases and nested assets", async () => {
+    const rootDir = createTempDir("openclaw-tsdown-build-");
+    const distDir = path.join(rootDir, "dist");
+    const distRuntimeDir = path.join(rootDir, "dist-runtime");
+    await fsPromises.mkdir(path.join(distDir, "control-ui"), { recursive: true });
+    await fsPromises.mkdir(distRuntimeDir, { recursive: true });
+    await fsPromises.writeFile(path.join(distDir, "delegate-BPjCe4gC.js"), "old delegate\n");
+    await fsPromises.writeFile(path.join(distDir, "compact.runtime-2DiEmVcA.js"), "old runtime\n");
+    await fsPromises.writeFile(path.join(distDir, "compact.runtime.js"), "stable alias\n");
+    await fsPromises.writeFile(path.join(distDir, "entry.js"), "entry\n");
+    await fsPromises.writeFile(path.join(distDir, "control-ui", "index.html"), "asset\n");
+    await fsPromises.writeFile(
+      path.join(distRuntimeDir, "heartbeat-runner.runtime-fspOEj_1.js"),
+      "old runtime\n",
+    );
+    await fsPromises.writeFile(path.join(distRuntimeDir, "heartbeat-runner.runtime.js"), "alias\n");
+
+    pruneStaleRootChunkFiles({ cwd: rootDir });
+
+    await expect(
+      fsPromises.readFile(path.join(distDir, "compact.runtime.js"), "utf8"),
+    ).resolves.toBe("stable alias\n");
+    await expect(fsPromises.readFile(path.join(distDir, "entry.js"), "utf8")).resolves.toBe(
+      "entry\n",
+    );
+    await expect(
+      fsPromises.readFile(path.join(distDir, "control-ui", "index.html"), "utf8"),
+    ).resolves.toBe("asset\n");
+    await expect(
+      fsPromises.readFile(path.join(distRuntimeDir, "heartbeat-runner.runtime.js"), "utf8"),
+    ).resolves.toBe("alias\n");
+    await expect(fsPromises.stat(path.join(distDir, "delegate-BPjCe4gC.js"))).rejects.toThrow();
+    await expect(
+      fsPromises.stat(path.join(distDir, "compact.runtime-2DiEmVcA.js")),
+    ).rejects.toThrow();
+    await expect(
+      fsPromises.stat(path.join(distRuntimeDir, "heartbeat-runner.runtime-fspOEj_1.js")),
+    ).rejects.toThrow();
+  });
 });