feat: enhance list-branches endpoint to support fetching remote branches

- Updated the list-branches endpoint to accept an optional parameter for including remote branches.
- Implemented logic to fetch and deduplicate remote branches alongside local branches.
- Modified the CreatePRDialog component to utilize the updated API for branch selection, allowing users to select from both local and remote branches.

apps/server/src/routes/worktree/routes/list-branches.ts

@@ -1,5 +1,5 @@
 /**
- * POST /list-branches endpoint - List all local branches
+ * POST /list-branches endpoint - List all local branches and optionally remote branches
  *
  * Note: Git repository validation (isGitRepo, hasCommits) is handled by
  * the requireValidWorktree middleware in index.ts
@@ -21,8 +21,9 @@ interface BranchInfo {
 export function createListBranchesHandler() {
   return async (req: Request, res: Response): Promise<void> => {
     try {
-      const { worktreePath } = req.body as {
+      const { worktreePath, includeRemote = false } = req.body as {
         worktreePath: string;
+        includeRemote?: boolean;
       };
 
       if (!worktreePath) {
@@ -60,6 +61,55 @@ export function createListBranchesHandler() {
           };
         });
 
+      // Fetch remote branches if requested
+      if (includeRemote) {
+        try {
+          // Fetch latest remote refs (silently, don't fail if offline)
+          try {
+            await execAsync('git fetch --all --quiet', {
+              cwd: worktreePath,
+              timeout: 10000, // 10 second timeout
+            });
+          } catch {
+            // Ignore fetch errors - we'll use cached remote refs
+          }
+
+          // List remote branches
+          const { stdout: remoteBranchesOutput } = await execAsync(
+            'git branch -r --format="%(refname:short)"',
+            { cwd: worktreePath }
+          );
+
+          const localBranchNames = new Set(branches.map((b) => b.name));
+
+          remoteBranchesOutput
+            .trim()
+            .split('\n')
+            .filter((b) => b.trim())
+            .forEach((name) => {
+              // Remove any surrounding quotes
+              const cleanName = name.trim().replace(/^['"]|['"]$/g, '');
+              // Skip HEAD pointers like "origin/HEAD"
+              if (cleanName.includes('/HEAD')) return;
+
+              // Extract the branch name without the remote prefix for deduplication
+              // e.g., "origin/main" -> "main"
+              const branchNameWithoutRemote = cleanName.replace(/^[^/]+\//, '');
+
+              // Only add remote branches that don't exist locally (to avoid duplicates)
+              if (!localBranchNames.has(branchNameWithoutRemote)) {
+                branches.push({
+                  name: cleanName, // Keep full name like "origin/main"
+                  isCurrent: false,
+                  isRemote: true,
+                });
+              }
+            });
+        } catch {
+          // Ignore errors fetching remote branches - return local branches only
+        }
+      }
+
       // Get ahead/behind count for current branch
       let aheadCount = 0;
       let behindCount = 0;

apps/ui/src/components/views/board-view/dialogs/create-pr-dialog.tsx

@@ -1,4 +1,4 @@
-import { useState, useEffect, useRef } from 'react';
+import { useState, useEffect, useRef, useCallback } from 'react';
 import {
   Dialog,
   DialogContent,
@@ -12,6 +12,7 @@ import { Input } from '@/components/ui/input';
 import { Textarea } from '@/components/ui/textarea';
 import { Label } from '@/components/ui/label';
 import { Checkbox } from '@/components/ui/checkbox';
+import { BranchAutocomplete } from '@/components/ui/branch-autocomplete';
 import { GitPullRequest, Loader2, ExternalLink } from 'lucide-react';
 import { getElectronAPI } from '@/lib/electron';
 import { toast } from 'sonner';
@@ -52,9 +53,38 @@ export function CreatePRDialog({
   const [prUrl, setPrUrl] = useState<string | null>(null);
   const [browserUrl, setBrowserUrl] = useState<string | null>(null);
   const [showBrowserFallback, setShowBrowserFallback] = useState(false);
+  // Branch fetching state
+  const [branches, setBranches] = useState<string[]>([]);
+  const [isLoadingBranches, setIsLoadingBranches] = useState(false);
   // Track whether an operation completed that warrants a refresh
   const operationCompletedRef = useRef(false);
 
+  // Fetch branches for autocomplete
+  const fetchBranches = useCallback(async () => {
+    if (!worktree?.path) return;
+
+    setIsLoadingBranches(true);
+    try {
+      const api = getElectronAPI();
+      if (!api?.worktree?.listBranches) {
+        return;
+      }
+      // Fetch both local and remote branches for PR base branch selection
+      const result = await api.worktree.listBranches(worktree.path, true);
+      if (result.success && result.result) {
+        // Extract branch names, filtering out the current worktree branch
+        const branchNames = result.result.branches
+          .map((b) => b.name)
+          .filter((name) => name !== worktree.branch);
+        setBranches(branchNames);
+      }
+    } catch {
+      // Silently fail - branches will default to main only
+    } finally {
+      setIsLoadingBranches(false);
+    }
+  }, [worktree?.path, worktree?.branch]);
+
   // Reset state when dialog opens or worktree changes
   useEffect(() => {
     if (open) {
@@ -72,6 +102,9 @@ export function CreatePRDialog({
       setShowBrowserFallback(false);
       // Reset operation tracking
       operationCompletedRef.current = false;
+      // Reset branches and fetch fresh ones
+      setBranches([]);
+      fetchBranches();
     } else {
       // Reset everything when dialog closes
       setTitle('');
@@ -84,8 +117,9 @@ export function CreatePRDialog({
       setBrowserUrl(null);
       setShowBrowserFallback(false);
       operationCompletedRef.current = false;
+      setBranches([]);
     }
-  }, [open, worktree?.path, defaultBaseBranch]);
+  }, [open, worktree?.path, defaultBaseBranch, fetchBranches]);
 
   const handleCreate = async () => {
     if (!worktree) return;
@@ -346,15 +380,16 @@ export function CreatePRDialog({
                 />
               </div>
 
-              <div className="grid grid-cols-2 gap-4">
+              <div className="flex flex-col gap-4">
                 <div className="grid gap-2">
                   <Label htmlFor="base-branch">Base Branch</Label>
-                  <Input
-                    id="base-branch"
-                    placeholder="main"
+                  <BranchAutocomplete
                     value={baseBranch}
-                    onChange={(e) => setBaseBranch(e.target.value)}
-                    className="font-mono text-sm"
+                    onChange={setBaseBranch}
+                    branches={branches}
+                    placeholder="Select base branch..."
+                    disabled={isLoadingBranches}
+                    data-testid="base-branch-autocomplete"
                   />
                 </div>
                 <div className="flex items-end">

apps/ui/src/lib/http-api-client.ts

@@ -1746,8 +1746,8 @@ export class HttpApiClient implements ElectronAPI {
     pull: (worktreePath: string) => this.post('/api/worktree/pull', { worktreePath }),
     checkoutBranch: (worktreePath: string, branchName: string) =>
       this.post('/api/worktree/checkout-branch', { worktreePath, branchName }),
-    listBranches: (worktreePath: string) =>
-      this.post('/api/worktree/list-branches', { worktreePath }),
+    listBranches: (worktreePath: string, includeRemote?: boolean) =>
+      this.post('/api/worktree/list-branches', { worktreePath, includeRemote }),
     switchBranch: (worktreePath: string, branchName: string) =>
       this.post('/api/worktree/switch-branch', { worktreePath, branchName }),
     openInEditor: (worktreePath: string, editorCommand?: string) =>

apps/ui/src/types/electron.d.ts

@@ -858,8 +858,11 @@ export interface WorktreeAPI {
     code?: 'NOT_GIT_REPO' | 'NO_COMMITS';
   }>;
 
-  // List all local branches
-  listBranches: (worktreePath: string) => Promise<{
+  // List branches (local and optionally remote)
+  listBranches: (
+    worktreePath: string,
+    includeRemote?: boolean
+  ) => Promise<{
     success: boolean;
     result?: {
       currentBranch: string;