diff --git a/src/agents/system-prompt-params.ts b/src/agents/system-prompt-params.ts
index e35709009c..8aca020420 100644
--- a/src/agents/system-prompt-params.ts
+++ b/src/agents/system-prompt-params.ts
@@ -1,6 +1,7 @@
 import fs from "node:fs";
 import path from "node:path";
 import type { OpenClawConfig } from "../config/config.js";
+import { findGitRoot } from "../infra/git-root.js";
 import {
   formatUserTime,
   resolveUserTimeFormat,
@@ -92,24 +93,3 @@ function resolveRepoRoot(params: {
   }
   return undefined;
 }
-
-function findGitRoot(startDir: string): string | null {
-  let current = path.resolve(startDir);
-  for (let i = 0; i < 12; i += 1) {
-    const gitPath = path.join(current, ".git");
-    try {
-      const stat = fs.statSync(gitPath);
-      if (stat.isDirectory() || stat.isFile()) {
-        return current;
-      }
-    } catch {
-      // ignore missing .git at this level
-    }
-    const parent = path.dirname(current);
-    if (parent === current) {
-      break;
-    }
-    current = parent;
-  }
-  return null;
-}
diff --git a/src/infra/git-commit.ts b/src/infra/git-commit.ts
index e2b1d07f9d..44778ce5a0 100644
--- a/src/infra/git-commit.ts
+++ b/src/infra/git-commit.ts
@@ -1,6 +1,7 @@
 import fs from "node:fs";
 import { createRequire } from "node:module";
 import path from "node:path";
+import { resolveGitHeadPath } from "./git-root.js";
 
 const formatCommit = (value?: string | null) => {
   if (!value) {
@@ -13,35 +14,6 @@ const formatCommit = (value?: string | null) => {
   return trimmed.length > 7 ? trimmed.slice(0, 7) : trimmed;
 };
 
-const resolveGitHead = (startDir: string) => {
-  let current = startDir;
-  for (let i = 0; i < 12; i += 1) {
-    const gitPath = path.join(current, ".git");
-    try {
-      const stat = fs.statSync(gitPath);
-      if (stat.isDirectory()) {
-        return path.join(gitPath, "HEAD");
-      }
-      if (stat.isFile()) {
-        const raw = fs.readFileSync(gitPath, "utf-8");
-        const match = raw.match(/gitdir:\s*(.+)/i);
-        if (match?.[1]) {
-          const resolved = path.resolve(current, match[1].trim());
-          return path.join(resolved, "HEAD");
-        }
-      }
-    } catch {
-      // ignore missing .git at this level
-    }
-    const parent = path.dirname(current);
-    if (parent === current) {
-      break;
-    }
-    current = parent;
-  }
-  return null;
-};
-
 let cachedCommit: string | null | undefined;
 
 const readCommitFromPackageJson = () => {
@@ -102,7 +74,7 @@ export const resolveCommitHash = (options: { cwd?: string; env?: NodeJS.ProcessE
     return cachedCommit;
   }
   try {
-    const headPath = resolveGitHead(options.cwd ?? process.cwd());
+    const headPath = resolveGitHeadPath(options.cwd ?? process.cwd());
     if (!headPath) {
       cachedCommit = null;
       return cachedCommit;
diff --git a/src/infra/git-root.test.ts b/src/infra/git-root.test.ts
new file mode 100644
index 0000000000..ed313ac9f0
--- /dev/null
+++ b/src/infra/git-root.test.ts
@@ -0,0 +1,59 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+import { findGitRoot, resolveGitHeadPath } from "./git-root.js";
+
+async function makeTempDir(label: string): Promise<string> {
+  return fs.mkdtemp(path.join(os.tmpdir(), `openclaw-${label}-`));
+}
+
+describe("git-root", () => {
+  it("finds git root and HEAD path when .git is a directory", async () => {
+    const temp = await makeTempDir("git-root-dir");
+    const repoRoot = path.join(temp, "repo");
+    const workspace = path.join(repoRoot, "nested", "workspace");
+    await fs.mkdir(path.join(repoRoot, ".git"), { recursive: true });
+    await fs.mkdir(workspace, { recursive: true });
+
+    expect(findGitRoot(workspace)).toBe(repoRoot);
+    expect(resolveGitHeadPath(workspace)).toBe(path.join(repoRoot, ".git", "HEAD"));
+  });
+
+  it("resolves HEAD path when .git is a gitdir pointer file", async () => {
+    const temp = await makeTempDir("git-root-file");
+    const repoRoot = path.join(temp, "repo");
+    const workspace = path.join(repoRoot, "nested", "workspace");
+    const gitDir = path.join(repoRoot, ".actual-git");
+    await fs.mkdir(workspace, { recursive: true });
+    await fs.mkdir(gitDir, { recursive: true });
+    await fs.writeFile(path.join(repoRoot, ".git"), "gitdir: .actual-git\n", "utf-8");
+
+    expect(findGitRoot(workspace)).toBe(repoRoot);
+    expect(resolveGitHeadPath(workspace)).toBe(path.join(gitDir, "HEAD"));
+  });
+
+  it("keeps root detection for .git file and skips invalid gitdir content for HEAD lookup", async () => {
+    const temp = await makeTempDir("git-root-invalid-file");
+    const parentRoot = path.join(temp, "repo");
+    const childRoot = path.join(parentRoot, "child");
+    const nested = path.join(childRoot, "nested");
+    await fs.mkdir(path.join(parentRoot, ".git"), { recursive: true });
+    await fs.mkdir(nested, { recursive: true });
+    await fs.writeFile(path.join(childRoot, ".git"), "not-a-gitdir-pointer\n", "utf-8");
+
+    expect(findGitRoot(nested)).toBe(childRoot);
+    expect(resolveGitHeadPath(nested)).toBe(path.join(parentRoot, ".git", "HEAD"));
+  });
+
+  it("respects maxDepth traversal limit", async () => {
+    const temp = await makeTempDir("git-root-depth");
+    const repoRoot = path.join(temp, "repo");
+    const nested = path.join(repoRoot, "a", "b", "c");
+    await fs.mkdir(path.join(repoRoot, ".git"), { recursive: true });
+    await fs.mkdir(nested, { recursive: true });
+
+    expect(findGitRoot(nested, { maxDepth: 2 })).toBeNull();
+    expect(resolveGitHeadPath(nested, { maxDepth: 2 })).toBeNull();
+  });
+});
diff --git a/src/infra/git-root.ts b/src/infra/git-root.ts
new file mode 100644
index 0000000000..9966947079
--- /dev/null
+++ b/src/infra/git-root.ts
@@ -0,0 +1,72 @@
+import fs from "node:fs";
+import path from "node:path";
+
+export const DEFAULT_GIT_DISCOVERY_MAX_DEPTH = 12;
+
+function walkUpFrom<T>(
+  startDir: string,
+  opts: { maxDepth?: number },
+  resolveAtDir: (dir: string) => T | null | undefined,
+): T | null {
+  let current = path.resolve(startDir);
+  const maxDepth = opts.maxDepth ?? DEFAULT_GIT_DISCOVERY_MAX_DEPTH;
+  for (let i = 0; i < maxDepth; i += 1) {
+    const resolved = resolveAtDir(current);
+    if (resolved !== null && resolved !== undefined) {
+      return resolved;
+    }
+    const parent = path.dirname(current);
+    if (parent === current) {
+      break;
+    }
+    current = parent;
+  }
+  return null;
+}
+
+function hasGitMarker(repoRoot: string): boolean {
+  const gitPath = path.join(repoRoot, ".git");
+  try {
+    const stat = fs.statSync(gitPath);
+    return stat.isDirectory() || stat.isFile();
+  } catch {
+    return false;
+  }
+}
+
+export function findGitRoot(startDir: string, opts: { maxDepth?: number } = {}): string | null {
+  // A `.git` file counts as a repo marker even if it is not a valid gitdir pointer.
+  return walkUpFrom(startDir, opts, (repoRoot) => (hasGitMarker(repoRoot) ? repoRoot : null));
+}
+
+function resolveGitDirFromMarker(repoRoot: string): string | null {
+  const gitPath = path.join(repoRoot, ".git");
+  try {
+    const stat = fs.statSync(gitPath);
+    if (stat.isDirectory()) {
+      return gitPath;
+    }
+    if (!stat.isFile()) {
+      return null;
+    }
+    const raw = fs.readFileSync(gitPath, "utf-8");
+    const match = raw.match(/gitdir:\s*(.+)/i);
+    if (!match?.[1]) {
+      return null;
+    }
+    return path.resolve(repoRoot, match[1].trim());
+  } catch {
+    return null;
+  }
+}
+
+export function resolveGitHeadPath(
+  startDir: string,
+  opts: { maxDepth?: number } = {},
+): string | null {
+  // Stricter than findGitRoot: keep walking until a resolvable git dir is found.
+  return walkUpFrom(startDir, opts, (repoRoot) => {
+    const gitDir = resolveGitDirFromMarker(repoRoot);
+    return gitDir ? path.join(gitDir, "HEAD") : null;
+  });
+}