diff --git a/.agents/notes/implemented/bug-fix/2026-09-12-git-helper-cli-runtime.md b/.agents/notes/implemented/bug-fix/2026-09-12-git-helper-cli-runtime.md
new file mode 100644
index 000000000..716526a3c
--- /dev/null
+++ b/.agents/notes/implemented/bug-fix/2026-09-12-git-helper-cli-runtime.md
@@ -0,0 +1,20 @@
+# Run the git credential helper under the CLI runtime
+
+Status: implemented
+Translation: current
+PR: https://github.com/LodyAI/Lody/pull/644
+
+[中文](2026-09-12-git-helper-cli-runtime.zh.md)
+
+## Abstract
+
+GitHub HTTPS clone already has a token. Dock-launched Lody inherits the macOS GUI PATH
+(`/usr/bin:/bin:/usr/sbin:/sbin`), which has no `node`. The helper was
+`!node "helper.cjs"`, so git failed with `could not read Username` /
+`turn_pre_prompt_failed`. Token prefetch and the broker are in-process HTTP and never
+needed PATH `node`.
+
+Host helper is now `!"<process.execPath>" "helper.cjs"` (both words quoted; Windows `\`
+→ `/`). Electron also sets `ELECTRON_RUN_AS_NODE=1` so `Lody Helper` is not opened as a
+GUI. The diagnostic probe spawns `execPath`, not `node`. Container helpers stay `!node`
+because the image has `node` and the host execPath is not in the container.
diff --git a/.agents/notes/implemented/bug-fix/2026-09-12-git-helper-cli-runtime.zh.md b/.agents/notes/implemented/bug-fix/2026-09-12-git-helper-cli-runtime.zh.md
new file mode 100644
index 000000000..810902454
--- /dev/null
+++ b/.agents/notes/implemented/bug-fix/2026-09-12-git-helper-cli-runtime.zh.md
@@ -0,0 +1,20 @@
+# 在 CLI 自身运行时下执行 git 凭据助手
+
+Status: implemented
+Translation: current
+PR: https://github.com/LodyAI/Lody/pull/644
+
+[English](2026-09-12-git-helper-cli-runtime.md)
+
+## 摘要
+
+GitHub HTTPS clone 本身已经拿到了令牌。从 Dock 启动的 Lody 继承的是 macOS 图形界面的
+PATH（`/usr/bin:/bin:/usr/sbin:/sbin`），其中没有 `node`。而助手命令是
+`!node "helper.cjs"`，于是 git 以 `could not read Username` 失败，对外表现为
+`turn_pre_prompt_failed`。令牌预取和 Broker 都是进程内 HTTP，从来不需要 PATH 上的
+`node`。
+
+现在宿主机助手是 `!"<process.execPath>" "helper.cjs"`（两个词都加引号；Windows 上
+`\` → `/`）。在 Electron 下还会设置 `ELECTRON_RUN_AS_NODE=1`，避免把 `Lody Helper`
+当作 GUI 打开。诊断探针启动的是 `execPath` 而不是 `node`。容器内的助手仍为 `!node`，
+因为镜像里有 `node`，而宿主机的 execPath 并不存在于容器中。
diff --git a/apps/cli/src/lib/git-credential-helper-script.ts b/apps/cli/src/lib/git-credential-helper-script.ts
index a91ae5d78..39cdf95c3 100644
--- a/apps/cli/src/lib/git-credential-helper-script.ts
+++ b/apps/cli/src/lib/git-credential-helper-script.ts
@@ -338,12 +338,47 @@ export const ensureCredentialHelperScript = (repoId: RepoId): void => {
 
 const escapeForGitHelper = (value: string): string => value.replace(/"/g, '\\"');
 
-export const buildCredentialHelperValueForHost = (repoId: RepoId): string => {
-  const helperPath = escapeForGitHelper(getCredentialHelperHostPath(repoId));
-  return `!node "${helperPath}"`;
+/**
+ * Quote one word of a `credential.helper = !<shell command>` value.
+ *
+ * Git runs the `!` form through a shell — `sh` on POSIX, the bundled MinGW bash on
+ * Windows — so every path must be quoted (installation directories contain spaces:
+ * `Lody Helper`, `Program Files`) and Windows separators must be forward slashes,
+ * because backslashes are escape characters to that shell rather than separators.
+ */
+const quoteForGitHelper = (value: string): string => {
+  const normalized = process.platform === 'win32' ? value.replace(/\\/g, '/') : value;
+  return `"${escapeForGitHelper(normalized)}"`;
 };
 
+/**
+ * Host-side helpers run under the CLI's own runtime (`process.execPath`), never a bare
+ * `node`. A desktop launched from the macOS Dock (or a Windows shortcut) inherits the
+ * GUI PATH, which usually has no `node` at all: git would then fail to start the helper,
+ * find no username with `GIT_TERMINAL_PROMPT=0`, and abort the clone. This mirrors what
+ * the CLI/MCP/watch-worker spawns already do.
+ */
+export const buildCredentialHelperValueForHost = (repoId: RepoId): string =>
+  `!${quoteForGitHelper(process.execPath)} ${quoteForGitHelper(
+    getCredentialHelperHostPath(repoId)
+  )}`;
+
+/**
+ * Container helpers run inside the devcontainer image, where `node` is on PATH and the
+ * host's `process.execPath` does not exist.
+ */
 export const buildCredentialHelperValueForContainer = (repoId: RepoId): string => {
   const helperPath = escapeForGitHelper(getCredentialHelperContainerPath(repoId));
   return `!node "${helperPath}"`;
 };
+
+/**
+ * Extra environment every git child (and the diagnostic helper probe) needs so that
+ * running `process.execPath` starts a Node process. In the packaged desktop the CLI is
+ * the Electron binary; without this flag the helper invocation launches a second GUI
+ * app instead of executing the helper script.
+ */
+export const buildCredentialHelperRuntimeEnv = (): Record<string, string> =>
+  process.versions.electron || process.env.ELECTRON_RUN_AS_NODE
+    ? { ELECTRON_RUN_AS_NODE: '1' }
+    : {};
diff --git a/apps/cli/src/session/session-manager.ts b/apps/cli/src/session/session-manager.ts
index 1e5968ce8..bca96ba92 100644
--- a/apps/cli/src/session/session-manager.ts
+++ b/apps/cli/src/session/session-manager.ts
@@ -73,6 +73,7 @@ import {
 import type { CloudGithubTokenManager, CloudPort } from '@lody/platform';
 import { isDevEnv } from '@/utils/runtime-env';
 import {
+  buildCredentialHelperRuntimeEnv,
   buildCredentialHelperValueForHost,
   ensureCredentialHelperScript,
 } from '@/lib/git-credential-helper-script';
@@ -1591,6 +1592,9 @@ export class SessionManager extends EventEmitter<SessionManagerEvents> {
 
     config.env = {
       ...sessionEnv,
+      // The helper command is `process.execPath`, so ACP git children need this flag
+      // to run the packaged desktop binary as Node.
+      ...buildCredentialHelperRuntimeEnv(),
       LODY_GIT_CRED_BROKER_URL: brokerUrl,
       LODY_GIT_CRED_BROKER_TOKEN: brokerEnv.token,
       // Keeps the helper's connection-refused fallback inside this workspace instead
diff --git a/apps/cli/src/session/worktree/AGENTS.md b/apps/cli/src/session/worktree/AGENTS.md
index eace4cd1d..2bb22ce27 100644
--- a/apps/cli/src/session/worktree/AGENTS.md
+++ b/apps/cli/src/session/worktree/AGENTS.md
@@ -22,6 +22,14 @@ and file responsibilities: [../README.md](../README.md).
   (per-workspace `broker-<workspaceId>.json`) for the same reason. Diagnostics must probe the
   same broker the failing command used, or they report a misroute as the caller's workspace
   lacking the repo link. Regression test: `worktree-manager-broker-auth.test.ts`.
+- INVARIANT: never spawn a bare `node` for the credential helper. `credential.helper` is
+  built from `process.execPath` with both words quoted (Windows separators normalized to
+  `/` for git's MinGW bash), and the diagnostic probe spawns the same runtime. A desktop
+  launched from the Dock or a shortcut inherits the GUI PATH, which usually has no `node`,
+  so a `!node` helper never starts and git fails with `terminal prompts disabled` even
+  though the broker is healthy. Git children and the ACP session env also carry
+  `ELECTRON_RUN_AS_NODE=1` when the CLI is the Electron binary
+  ([note](../../../../../.agents/notes/implemented/bug-fix/2026-09-12-git-helper-cli-runtime.md)).
 
 ## Worktrees, branches, and setup
 
diff --git a/apps/cli/src/session/worktree/worktree-manager.ts b/apps/cli/src/session/worktree/worktree-manager.ts
index 4547beda0..5b91dbcea 100644
--- a/apps/cli/src/session/worktree/worktree-manager.ts
+++ b/apps/cli/src/session/worktree/worktree-manager.ts
@@ -7,6 +7,7 @@ import { Logger } from '@/utils/logger';
 import { withFileLock } from '@/utils/file-lock';
 import { redactUrlAuth } from '@/utils/github';
 import {
+  buildCredentialHelperRuntimeEnv,
   buildCredentialHelperValueForHost,
   ensureCredentialHelperScript,
   getCredentialHelperHostPath,
@@ -314,6 +315,9 @@ export class WorktreeManager {
     const mergedEnv: NodeJS.ProcessEnv = {
       ...process.env,
       ...env,
+      // The credential helper runs `process.execPath`; under Electron that binary only
+      // behaves as Node with this flag set.
+      ...buildCredentialHelperRuntimeEnv(),
       GIT_TERMINAL_PROMPT: '0',
     };
     this.logger.debug(`[${this.repoId}] Running git ${args.join(' ')}`);
@@ -565,6 +569,7 @@ export class WorktreeManager {
       const env: NodeJS.ProcessEnv = {
         ...process.env,
         ...buildBrokerAuthEnv(options.brokerAuth),
+        ...buildCredentialHelperRuntimeEnv(),
         LODY_GIT_CRED_HELPER_DEBUG: 'true',
         LODY_GIT_CRED_HELPER_DEBUG_FILE: debugFile,
       };
@@ -603,7 +608,11 @@ export class WorktreeManager {
   }): Promise<{ exitCode: number | null; returnedCredentials: boolean; stderrNonEmpty: boolean }> {
     const input = `protocol=https\nhost=${options.host}\npath=/${options.repoFullName}.git\n\n`;
     return await new Promise((resolve, reject) => {
-      const child = spawn('node', [options.helperPath, 'get'], {
+      // Probe with the SAME runtime git uses for the helper (`process.execPath`).
+      // Spawning a bare `node` would make the probe fail with ENOENT on a desktop
+      // launched from the Dock — exactly the failure being diagnosed — or, worse,
+      // succeed against an unrelated PATH Node and hide it.
+      const child = spawn(process.execPath, [options.helperPath, 'get'], {
         env: options.env,
         stdio: ['pipe', 'pipe', 'pipe'],
         windowsHide: true,
diff --git a/apps/cli/tests/worktree-manager.create.test.ts b/apps/cli/tests/worktree-manager.create.test.ts
index 2f9f56904..e6aa4d81a 100644
--- a/apps/cli/tests/worktree-manager.create.test.ts
+++ b/apps/cli/tests/worktree-manager.create.test.ts
@@ -75,11 +75,14 @@ describe('WorktreeManager', () => {
 
   describe('git credential config', () => {
     it('clears inherited helpers before installing the Lody helper', () => {
-      expect(buildGitHubCredentialConfigArgs('!node "/tmp/lody-helper.cjs"')).toEqual([
+      // The helper value names the CLI runtime explicitly and quotes both words,
+      // because installation paths contain spaces and the GUI PATH has no `node`.
+      const helperValue = '!"/Applications/Lody Helper.app/node" "/tmp/lody-helper.cjs"';
+      expect(buildGitHubCredentialConfigArgs(helperValue)).toEqual([
         '-c',
         'credential.helper=',
         '-c',
-        'credential.helper=!node "/tmp/lody-helper.cjs"',
+        `credential.helper=${helperValue}`,
         '-c',
         'credential.useHttpPath=true',
       ]);