diff --git a/apps/app/src/components/ui/git-diff-panel.tsx b/apps/app/src/components/ui/git-diff-panel.tsx
index d6789547..b00e9d8e 100644
--- a/apps/app/src/components/ui/git-diff-panel.tsx
+++ b/apps/app/src/components/ui/git-diff-panel.tsx
@@ -620,6 +620,41 @@ export function GitDiffPanel({
                     onToggle={() => toggleFile(fileDiff.filePath)}
                   />
                 ))}
+                {/* Fallback for files that have no diff content (shouldn't happen after fix, but safety net) */}
+                {files.length > 0 && parsedDiffs.length === 0 && (
+                  <div className="space-y-2">
+                    {files.map((file) => (
+                      <div
+                        key={file.path}
+                        className="border border-border rounded-lg overflow-hidden"
+                      >
+                        <div className="w-full px-3 py-2 flex items-center gap-2 text-left bg-card">
+                          {getFileIcon(file.status)}
+                          <span className="flex-1 text-sm font-mono truncate text-foreground">
+                            {file.path}
+                          </span>
+                          <span
+                            className={cn(
+                              "text-xs px-1.5 py-0.5 rounded border font-medium",
+                              getStatusBadgeColor(file.status)
+                            )}
+                          >
+                            {getStatusDisplayName(file.status)}
+                          </span>
+                        </div>
+                        <div className="px-4 py-3 text-sm text-muted-foreground bg-background border-t border-border">
+                          {file.status === "?" ? (
+                            <span>New file - content preview not available</span>
+                          ) : file.status === "D" ? (
+                            <span>File deleted</span>
+                          ) : (
+                            <span>Diff content not available</span>
+                          )}
+                        </div>
+                      </div>
+                    ))}
+                  </div>
+                )}
               </div>
             </div>
           )}
diff --git a/apps/server/src/routes/common.ts b/apps/server/src/routes/common.ts
index 8a1fcc68..d1308b30 100644
--- a/apps/server/src/routes/common.ts
+++ b/apps/server/src/routes/common.ts
@@ -3,9 +3,304 @@
  */
 
 import { createLogger } from "../lib/logger.js";
+import fs from "fs/promises";
+import path from "path";
+import { exec } from "child_process";
+import { promisify } from "util";
 
 type Logger = ReturnType<typeof createLogger>;
 
+const execAsync = promisify(exec);
+const logger = createLogger("Common");
+
+// Max file size for generating synthetic diffs (1MB)
+const MAX_SYNTHETIC_DIFF_SIZE = 1024 * 1024;
+
+// Binary file extensions to skip
+const BINARY_EXTENSIONS = new Set([
+  ".png", ".jpg", ".jpeg", ".gif", ".bmp", ".ico", ".webp", ".svg",
+  ".pdf", ".doc", ".docx", ".xls", ".xlsx", ".ppt", ".pptx",
+  ".zip", ".tar", ".gz", ".rar", ".7z",
+  ".exe", ".dll", ".so", ".dylib",
+  ".mp3", ".mp4", ".wav", ".avi", ".mov", ".mkv",
+  ".ttf", ".otf", ".woff", ".woff2", ".eot",
+  ".db", ".sqlite", ".sqlite3",
+  ".pyc", ".pyo", ".class", ".o", ".obj",
+]);
+
+// Status map for git status codes
+const GIT_STATUS_MAP: Record<string, string> = {
+  M: "Modified",
+  A: "Added",
+  D: "Deleted",
+  R: "Renamed",
+  C: "Copied",
+  U: "Updated",
+  "?": "Untracked",
+};
+
+/**
+ * File status interface for git status results
+ */
+export interface FileStatus {
+  status: string;
+  path: string;
+  statusText: string;
+}
+
+/**
+ * Check if a file is likely binary based on extension
+ */
+function isBinaryFile(filePath: string): boolean {
+  const ext = path.extname(filePath).toLowerCase();
+  return BINARY_EXTENSIONS.has(ext);
+}
+
+/**
+ * Check if a path is a git repository
+ */
+export async function isGitRepo(repoPath: string): Promise<boolean> {
+  try {
+    await execAsync("git rev-parse --is-inside-work-tree", { cwd: repoPath });
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Parse the output of `git status --porcelain` into FileStatus array
+ */
+export function parseGitStatus(statusOutput: string): FileStatus[] {
+  return statusOutput
+    .split("\n")
+    .filter(Boolean)
+    .map((line) => {
+      const statusChar = line[0];
+      const filePath = line.slice(3);
+      return {
+        status: statusChar,
+        path: filePath,
+        statusText: GIT_STATUS_MAP[statusChar] || "Unknown",
+      };
+    });
+}
+
+/**
+ * Generate a synthetic unified diff for an untracked (new) file
+ * This is needed because `git diff HEAD` doesn't include untracked files
+ */
+export async function generateSyntheticDiffForNewFile(
+  basePath: string,
+  relativePath: string
+): Promise<string> {
+  const fullPath = path.join(basePath, relativePath);
+
+  try {
+    // Check if it's a binary file
+    if (isBinaryFile(relativePath)) {
+      return `diff --git a/${relativePath} b/${relativePath}
+new file mode 100644
+index 0000000..0000000
+Binary file ${relativePath} added
+`;
+    }
+
+    // Get file stats to check size
+    const stats = await fs.stat(fullPath);
+    if (stats.size > MAX_SYNTHETIC_DIFF_SIZE) {
+      const sizeKB = Math.round(stats.size / 1024);
+      return `diff --git a/${relativePath} b/${relativePath}
+new file mode 100644
+index 0000000..0000000
+--- /dev/null
++++ b/${relativePath}
+@@ -0,0 +1 @@
++[File too large to display: ${sizeKB}KB]
+`;
+    }
+
+    // Read file content
+    const content = await fs.readFile(fullPath, "utf-8");
+    const hasTrailingNewline = content.endsWith("\n");
+    const lines = content.split("\n");
+
+    // Remove trailing empty line if the file ends with newline
+    if (lines.length > 0 && lines.at(-1) === "") {
+      lines.pop();
+    }
+
+    // Generate diff format
+    const lineCount = lines.length;
+    const addedLines = lines.map(line => `+${line}`).join("\n");
+
+    let diff = `diff --git a/${relativePath} b/${relativePath}
+new file mode 100644
+index 0000000..0000000
+--- /dev/null
++++ b/${relativePath}
+@@ -0,0 +1,${lineCount} @@
+${addedLines}`;
+
+    // Add "No newline at end of file" indicator if needed
+    if (!hasTrailingNewline && content.length > 0) {
+      diff += "\n\\ No newline at end of file";
+    }
+
+    return diff + "\n";
+  } catch (error) {
+    // Log the error for debugging
+    logger.error(`Failed to generate synthetic diff for ${fullPath}:`, error);
+    // Return a placeholder diff
+    return `diff --git a/${relativePath} b/${relativePath}
+new file mode 100644
+index 0000000..0000000
+--- /dev/null
++++ b/${relativePath}
+@@ -0,0 +1 @@
++[Unable to read file content]
+`;
+  }
+}
+
+/**
+ * Generate synthetic diffs for all untracked files and combine with existing diff
+ */
+export async function appendUntrackedFileDiffs(
+  basePath: string,
+  existingDiff: string,
+  files: Array<{ status: string; path: string }>
+): Promise<string> {
+  // Find untracked files (status "?")
+  const untrackedFiles = files.filter(f => f.status === "?");
+
+  if (untrackedFiles.length === 0) {
+    return existingDiff;
+  }
+
+  // Generate synthetic diffs for each untracked file
+  const syntheticDiffs = await Promise.all(
+    untrackedFiles.map(f => generateSyntheticDiffForNewFile(basePath, f.path))
+  );
+
+  // Combine existing diff with synthetic diffs
+  const combinedDiff = existingDiff + syntheticDiffs.join("");
+
+  return combinedDiff;
+}
+
+/**
+ * List all files in a directory recursively (for non-git repositories)
+ * Excludes hidden files/folders and common build artifacts
+ */
+export async function listAllFilesInDirectory(
+  basePath: string,
+  relativePath: string = ""
+): Promise<string[]> {
+  const files: string[] = [];
+  const fullPath = path.join(basePath, relativePath);
+
+  // Directories to skip
+  const skipDirs = new Set([
+    "node_modules", ".git", ".automaker", "dist", "build",
+    ".next", ".nuxt", "__pycache__", ".cache", "coverage"
+  ]);
+
+  try {
+    const entries = await fs.readdir(fullPath, { withFileTypes: true });
+
+    for (const entry of entries) {
+      // Skip hidden files/folders (except we want to allow some)
+      if (entry.name.startsWith(".") && entry.name !== ".env") {
+        continue;
+      }
+
+      const entryRelPath = relativePath ? `${relativePath}/${entry.name}` : entry.name;
+
+      if (entry.isDirectory()) {
+        if (!skipDirs.has(entry.name)) {
+          const subFiles = await listAllFilesInDirectory(basePath, entryRelPath);
+          files.push(...subFiles);
+        }
+      } else if (entry.isFile()) {
+        files.push(entryRelPath);
+      }
+    }
+  } catch (error) {
+    // Log the error to help diagnose file system issues
+    logger.error(`Error reading directory ${fullPath}:`, error);
+  }
+
+  return files;
+}
+
+/**
+ * Generate diffs for all files in a non-git directory
+ * Treats all files as "new" files
+ */
+export async function generateDiffsForNonGitDirectory(
+  basePath: string
+): Promise<{ diff: string; files: FileStatus[] }> {
+  const allFiles = await listAllFilesInDirectory(basePath);
+
+  const files: FileStatus[] = allFiles.map(filePath => ({
+    status: "?",
+    path: filePath,
+    statusText: "New",
+  }));
+
+  // Generate synthetic diffs for all files
+  const syntheticDiffs = await Promise.all(
+    files.map(f => generateSyntheticDiffForNewFile(basePath, f.path))
+  );
+
+  return {
+    diff: syntheticDiffs.join(""),
+    files,
+  };
+}
+
+/**
+ * Get git repository diffs for a given path
+ * Handles both git repos and non-git directories
+ */
+export async function getGitRepositoryDiffs(
+  repoPath: string
+): Promise<{ diff: string; files: FileStatus[]; hasChanges: boolean }> {
+  // Check if it's a git repository
+  const isRepo = await isGitRepo(repoPath);
+
+  if (!isRepo) {
+    // Not a git repo - list all files and treat them as new
+    const result = await generateDiffsForNonGitDirectory(repoPath);
+    return {
+      diff: result.diff,
+      files: result.files,
+      hasChanges: result.files.length > 0,
+    };
+  }
+
+  // Get git diff and status
+  const { stdout: diff } = await execAsync("git diff HEAD", {
+    cwd: repoPath,
+    maxBuffer: 10 * 1024 * 1024,
+  });
+  const { stdout: status } = await execAsync("git status --porcelain", {
+    cwd: repoPath,
+  });
+
+  const files = parseGitStatus(status);
+
+  // Generate synthetic diffs for untracked (new) files
+  const combinedDiff = await appendUntrackedFileDiffs(repoPath, diff, files);
+
+  return {
+    diff: combinedDiff,
+    files,
+    hasChanges: files.length > 0,
+  };
+}
+
 /**
  * Get error message from error object
  */
diff --git a/apps/server/src/routes/git/routes/diffs.ts b/apps/server/src/routes/git/routes/diffs.ts
index dd0e809f..eb532a03 100644
--- a/apps/server/src/routes/git/routes/diffs.ts
+++ b/apps/server/src/routes/git/routes/diffs.ts
@@ -3,11 +3,8 @@
  */
 
 import type { Request, Response } from "express";
-import { exec } from "child_process";
-import { promisify } from "util";
 import { getErrorMessage, logError } from "../common.js";
-
-const execAsync = promisify(exec);
+import { getGitRepositoryDiffs } from "../../common.js";
 
 export function createDiffsHandler() {
   return async (req: Request, res: Response): Promise<void> => {
@@ -20,43 +17,15 @@ export function createDiffsHandler() {
       }
 
       try {
-        const { stdout: diff } = await execAsync("git diff HEAD", {
-          cwd: projectPath,
-          maxBuffer: 10 * 1024 * 1024,
-        });
-        const { stdout: status } = await execAsync("git status --porcelain", {
-          cwd: projectPath,
-        });
-
-        const files = status
-          .split("\n")
-          .filter(Boolean)
-          .map((line) => {
-            const statusChar = line[0];
-            const filePath = line.slice(3);
-            const statusMap: Record<string, string> = {
-              M: "Modified",
-              A: "Added",
-              D: "Deleted",
-              R: "Renamed",
-              C: "Copied",
-              U: "Updated",
-              "?": "Untracked",
-            };
-            return {
-              status: statusChar,
-              path: filePath,
-              statusText: statusMap[statusChar] || "Unknown",
-            };
-          });
-
+        const result = await getGitRepositoryDiffs(projectPath);
         res.json({
           success: true,
-          diff,
-          files,
-          hasChanges: files.length > 0,
+          diff: result.diff,
+          files: result.files,
+          hasChanges: result.hasChanges,
         });
-      } catch {
+      } catch (innerError) {
+        logError(innerError, "Git diff failed");
         res.json({ success: true, diff: "", files: [], hasChanges: false });
       }
     } catch (error) {
diff --git a/apps/server/src/routes/git/routes/file-diff.ts b/apps/server/src/routes/git/routes/file-diff.ts
index 7f480a6f..fdf66998 100644
--- a/apps/server/src/routes/git/routes/file-diff.ts
+++ b/apps/server/src/routes/git/routes/file-diff.ts
@@ -6,6 +6,7 @@ import type { Request, Response } from "express";
 import { exec } from "child_process";
 import { promisify } from "util";
 import { getErrorMessage, logError } from "../common.js";
+import { generateSyntheticDiffForNewFile } from "../../common.js";
 
 const execAsync = promisify(exec);
 
@@ -25,16 +26,33 @@ export function createFileDiffHandler() {
       }
 
       try {
-        const { stdout: diff } = await execAsync(
-          `git diff HEAD -- "${filePath}"`,
-          {
-            cwd: projectPath,
-            maxBuffer: 10 * 1024 * 1024,
-          }
+        // First check if the file is untracked
+        const { stdout: status } = await execAsync(
+          `git status --porcelain -- "${filePath}"`,
+          { cwd: projectPath }
         );
 
+        const isUntracked = status.trim().startsWith("??");
+
+        let diff: string;
+        if (isUntracked) {
+          // Generate synthetic diff for untracked file
+          diff = await generateSyntheticDiffForNewFile(projectPath, filePath);
+        } else {
+          // Use regular git diff for tracked files
+          const result = await execAsync(
+            `git diff HEAD -- "${filePath}"`,
+            {
+              cwd: projectPath,
+              maxBuffer: 10 * 1024 * 1024,
+            }
+          );
+          diff = result.stdout;
+        }
+
         res.json({ success: true, diff, filePath });
-      } catch {
+      } catch (innerError) {
+        logError(innerError, "Git file diff failed");
         res.json({ success: true, diff: "", filePath });
       }
     } catch (error) {
diff --git a/apps/server/src/routes/worktree/routes/diffs.ts b/apps/server/src/routes/worktree/routes/diffs.ts
index cc2c6cf4..b9823902 100644
--- a/apps/server/src/routes/worktree/routes/diffs.ts
+++ b/apps/server/src/routes/worktree/routes/diffs.ts
@@ -3,13 +3,10 @@
  */
 
 import type { Request, Response } from "express";
-import { exec } from "child_process";
-import { promisify } from "util";
 import path from "path";
 import fs from "fs/promises";
 import { getErrorMessage, logError } from "../common.js";
-
-const execAsync = promisify(exec);
+import { getGitRepositoryDiffs } from "../../common.js";
 
 export function createDiffsHandler() {
   return async (req: Request, res: Response): Promise<void> => {
@@ -37,45 +34,33 @@ export function createDiffsHandler() {
       );
 
       try {
+        // Check if worktree exists
         await fs.access(worktreePath);
-        const { stdout: diff } = await execAsync("git diff HEAD", {
-          cwd: worktreePath,
-          maxBuffer: 10 * 1024 * 1024,
-        });
-        const { stdout: status } = await execAsync("git status --porcelain", {
-          cwd: worktreePath,
-        });
-
-        const files = status
-          .split("\n")
-          .filter(Boolean)
-          .map((line) => {
-            const statusChar = line[0];
-            const filePath = line.slice(3);
-            const statusMap: Record<string, string> = {
-              M: "Modified",
-              A: "Added",
-              D: "Deleted",
-              R: "Renamed",
-              C: "Copied",
-              U: "Updated",
-              "?": "Untracked",
-            };
-            return {
-              status: statusChar,
-              path: filePath,
-              statusText: statusMap[statusChar] || "Unknown",
-            };
-          });
 
+        // Get diffs from worktree
+        const result = await getGitRepositoryDiffs(worktreePath);
         res.json({
           success: true,
-          diff,
-          files,
-          hasChanges: files.length > 0,
+          diff: result.diff,
+          files: result.files,
+          hasChanges: result.hasChanges,
         });
-      } catch {
-        res.json({ success: true, diff: "", files: [], hasChanges: false });
+      } catch (innerError) {
+        // Worktree doesn't exist - fallback to main project path
+        logError(innerError, "Worktree access failed, falling back to main project");
+
+        try {
+          const result = await getGitRepositoryDiffs(projectPath);
+          res.json({
+            success: true,
+            diff: result.diff,
+            files: result.files,
+            hasChanges: result.hasChanges,
+          });
+        } catch (fallbackError) {
+          logError(fallbackError, "Fallback to main project also failed");
+          res.json({ success: true, diff: "", files: [], hasChanges: false });
+        }
       }
     } catch (error) {
       logError(error, "Get worktree diffs failed");
diff --git a/apps/server/src/routes/worktree/routes/file-diff.ts b/apps/server/src/routes/worktree/routes/file-diff.ts
index 27fafba5..a9cc4faf 100644
--- a/apps/server/src/routes/worktree/routes/file-diff.ts
+++ b/apps/server/src/routes/worktree/routes/file-diff.ts
@@ -8,6 +8,7 @@ import { promisify } from "util";
 import path from "path";
 import fs from "fs/promises";
 import { getErrorMessage, logError } from "../common.js";
+import { generateSyntheticDiffForNewFile } from "../../common.js";
 
 const execAsync = promisify(exec);
 
@@ -37,16 +38,34 @@ export function createFileDiffHandler() {
 
       try {
         await fs.access(worktreePath);
-        const { stdout: diff } = await execAsync(
-          `git diff HEAD -- "${filePath}"`,
-          {
-            cwd: worktreePath,
-            maxBuffer: 10 * 1024 * 1024,
-          }
+
+        // First check if the file is untracked
+        const { stdout: status } = await execAsync(
+          `git status --porcelain -- "${filePath}"`,
+          { cwd: worktreePath }
         );
 
+        const isUntracked = status.trim().startsWith("??");
+
+        let diff: string;
+        if (isUntracked) {
+          // Generate synthetic diff for untracked file
+          diff = await generateSyntheticDiffForNewFile(worktreePath, filePath);
+        } else {
+          // Use regular git diff for tracked files
+          const result = await execAsync(
+            `git diff HEAD -- "${filePath}"`,
+            {
+              cwd: worktreePath,
+              maxBuffer: 10 * 1024 * 1024,
+            }
+          );
+          diff = result.stdout;
+        }
+
         res.json({ success: true, diff, filePath });
-      } catch {
+      } catch (innerError) {
+        logError(innerError, "Worktree file diff failed");
         res.json({ success: true, diff: "", filePath });
       }
     } catch (error) {