diff --git a/packages/core/src/utils/shell-ast-parser-lazy.test.ts b/packages/core/src/utils/shell-ast-parser-lazy.test.ts
new file mode 100644
index 00000000000..244efd00b90
--- /dev/null
+++ b/packages/core/src/utils/shell-ast-parser-lazy.test.ts
@@ -0,0 +1,205 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import path from 'node:path';
+import { fileURLToPath, pathToFileURL } from 'node:url';
+import { createRequire } from 'node:module';
+import { build, type Metafile, type Plugin } from 'esbuild';
+import { afterEach, describe, expect, it, vi } from 'vitest';
+
+const repoRoot = fileURLToPath(new URL('../../../../', import.meta.url));
+const tempDirs: string[] = [];
+
+afterEach(() => {
+  vi.doUnmock('web-tree-sitter');
+  vi.resetModules();
+  for (const dir of tempDirs.splice(0)) {
+    rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+function wasmBinaryPlugin(): Plugin {
+  return {
+    name: 'wasm-binary-test',
+    setup(pluginBuild) {
+      pluginBuild.onResolve({ filter: /\.wasm\?binary$/ }, (args) => {
+        const specifier = args.path.replace(/\?binary$/, '');
+        const localRequire = createRequire(
+          path.resolve(args.resolveDir || repoRoot, '_dummy_.js'),
+        );
+        return {
+          path: localRequire.resolve(specifier),
+          namespace: 'wasm-binary',
+        };
+      });
+      pluginBuild.onLoad(
+        { filter: /.*/, namespace: 'wasm-binary' },
+        (args) => ({
+          contents: readFileSync(args.path),
+          loader: 'binary',
+        }),
+      );
+    },
+  };
+}
+
+function staticClosure(metafile: Metafile, entry: string): Set<string> {
+  const closure = new Set<string>();
+  const pending = [entry];
+  while (pending.length > 0) {
+    const outputPath = pending.pop()!;
+    if (closure.has(outputPath)) continue;
+    const output = metafile.outputs[outputPath];
+    if (!output) throw new Error(`Missing metafile output: ${outputPath}`);
+    closure.add(outputPath);
+    for (const imported of output.imports) {
+      if (!imported.external && imported.kind !== 'dynamic-import') {
+        pending.push(imported.path);
+      }
+    }
+  }
+  return closure;
+}
+
+function expectDeferredInput(
+  metafile: Metafile,
+  closure: Set<string>,
+  inputFragment: string,
+): void {
+  const owningOutputs = Object.entries(metafile.outputs).filter(([, output]) =>
+    Object.keys(output.inputs).some((input) =>
+      input.replaceAll('\\', '/').includes(inputFragment),
+    ),
+  );
+  expect(owningOutputs.length).toBeGreaterThan(0);
+  expect(owningOutputs.every(([outputPath]) => !closure.has(outputPath))).toBe(
+    true,
+  );
+}
+
+describe('shellAstParser lazy runtime', () => {
+  it('loads web-tree-sitter on first use and deduplicates initialization', async () => {
+    const runtimeLoaded = vi.fn();
+    const init = vi.fn(async () => undefined);
+
+    class ParserMock {
+      static init = init;
+      static Language = { load: vi.fn(async () => ({})) };
+
+      setLanguage = vi.fn();
+    }
+
+    vi.doMock('web-tree-sitter', () => {
+      runtimeLoaded();
+      return { default: ParserMock };
+    });
+
+    const parser = await import('./shellAstParser.js');
+    expect(runtimeLoaded).not.toHaveBeenCalled();
+
+    await Promise.all([parser.initParser(), parser.initParser()]);
+
+    expect(runtimeLoaded).toHaveBeenCalledTimes(1);
+    expect(init).toHaveBeenCalledTimes(1);
+  });
+
+  it('latches a runtime import failure and falls back without retrying', async () => {
+    const runtimeLoads = vi.fn();
+    vi.doMock('web-tree-sitter', () => {
+      runtimeLoads();
+      throw new Error('runtime chunk unavailable');
+    });
+
+    const parser = await import('./shellAstParser.js');
+    expect(await parser.isShellCommandReadOnlyAST('git status')).toBe(true);
+    expect(await parser.isShellCommandReadOnlyAST('rm -rf temp')).toBe(false);
+    await expect(parser.initParser()).rejects.toThrow(
+      'tree-sitter WASM failed to initialise',
+    );
+    expect(runtimeLoads).toHaveBeenCalledTimes(1);
+  });
+
+  it('keeps the packaged runtime deferred and parses from emitted chunks', async () => {
+    const tempDir = mkdtempSync(path.join(tmpdir(), 'qwen-shell-ast-parser-'));
+    tempDirs.push(tempDir);
+    const entryPath = path.join(tempDir, 'entry.ts');
+    writeFileSync(
+      entryPath,
+      `export { _resetParser, isShellCommandReadOnlyAST, parseShellCommand } from ${JSON.stringify(
+        path.join(repoRoot, 'packages/core/src/utils/shellAstParser.ts'),
+      )};\n`,
+    );
+
+    const result = await build({
+      absWorkingDir: tempDir,
+      entryPoints: { entry: entryPath },
+      bundle: true,
+      outdir: 'dist',
+      entryNames: '[name]',
+      chunkNames: 'chunks/[name]-[hash]',
+      splitting: true,
+      platform: 'node',
+      format: 'esm',
+      target: 'node22',
+      metafile: true,
+      inject: [path.join(repoRoot, 'scripts/esbuild-shims.js')],
+      define: {
+        __dirname: '__qwen_dirname',
+        __filename: '__qwen_filename',
+        global: 'globalThis',
+      },
+      plugins: [wasmBinaryPlugin()],
+      logLevel: 'silent',
+    });
+    writeFileSync(
+      path.join(tempDir, 'dist/package.json'),
+      JSON.stringify({ type: 'module' }),
+    );
+
+    const closure = staticClosure(result.metafile, 'dist/entry.js');
+    for (const inputFragment of [
+      'node_modules/web-tree-sitter/tree-sitter.js',
+      'node_modules/web-tree-sitter/tree-sitter.wasm',
+      'node_modules/tree-sitter-wasms/out/tree-sitter-bash.wasm',
+    ]) {
+      expectDeferredInput(result.metafile, closure, inputFragment);
+    }
+
+    const packagedParser = (await import(
+      /* @vite-ignore */ `${
+        pathToFileURL(path.join(tempDir, 'dist/entry.js')).href
+      }?test=${Date.now()}`
+    )) as {
+      _resetParser(): void;
+      isShellCommandReadOnlyAST(command: string): Promise<boolean>;
+      parseShellCommand(command: string): Promise<{
+        rootNode: { type: string };
+        delete(): void;
+      }>;
+    };
+    const [treeA, treeB] = await Promise.all([
+      packagedParser.parseShellCommand('git status --short'),
+      packagedParser.parseShellCommand('echo ready | grep ready'),
+    ]);
+    expect(treeA.rootNode.type).toBe('program');
+    expect(treeB.rootNode.type).toBe('program');
+    treeA.delete();
+    treeB.delete();
+    expect(await packagedParser.isShellCommandReadOnlyAST('git status')).toBe(
+      true,
+    );
+    expect(await packagedParser.isShellCommandReadOnlyAST('rm -rf temp')).toBe(
+      false,
+    );
+
+    packagedParser._resetParser();
+    const recoveredTree = await packagedParser.parseShellCommand('pwd');
+    expect(recoveredTree.rootNode.type).toBe('program');
+    recoveredTree.delete();
+  }, 20_000);
+});
diff --git a/packages/core/src/utils/shellAstParser.ts b/packages/core/src/utils/shellAstParser.ts
index 055e2f5629f..3ad7e87ccf3 100644
--- a/packages/core/src/utils/shellAstParser.ts
+++ b/packages/core/src/utils/shellAstParser.ts
@@ -14,7 +14,7 @@
  *   4. `extractCommandRules()`  – extract minimum-scope wildcard permission rules
  */
 
-import Parser from 'web-tree-sitter';
+import type Parser from 'web-tree-sitter';
 import fs from 'node:fs';
 import { createRequire } from 'node:module';
 import path from 'node:path';
@@ -619,18 +619,23 @@ export async function initParser(): Promise<void> {
   if (initPromise) return initPromise;
 
   initPromise = (async () => {
+    // Dynamically import the web-tree-sitter runtime to minimize synchronous bundle size.
+    const { default: ParserClass } = (await import(
+      'web-tree-sitter'
+    )) as unknown as { default: typeof Parser };
+
     const treeSitterWasm = await loadWasmBinary(
       () => import('web-tree-sitter/tree-sitter.wasm?binary' as string),
       'web-tree-sitter/tree-sitter.wasm',
     );
-    await Parser.init({ wasmBinary: treeSitterWasm });
-    parserInstance = new Parser();
+    await ParserClass.init({ wasmBinary: treeSitterWasm });
+    parserInstance = new ParserClass();
     const bashWasm = await loadWasmBinary(
       () =>
         import('tree-sitter-wasms/out/tree-sitter-bash.wasm?binary' as string),
       'tree-sitter-wasms/out/tree-sitter-bash.wasm',
     );
-    bashLanguage = await Parser.Language.load(bashWasm);
+    bashLanguage = await ParserClass.Language.load(bashWasm);
     parserInstance.setLanguage(bashLanguage);
   })().catch((err: unknown) => {
     // Mark as permanently failed so callers can use the regex fallback