diff --git a/.opencode/plans/1773656570427-mighty-tiger.md b/.opencode/plans/1773656570427-mighty-tiger.md
index f622b79..8d601b2 100644
--- a/.opencode/plans/1773656570427-mighty-tiger.md
+++ b/.opencode/plans/1773656570427-mighty-tiger.md
@@ -127,7 +127,13 @@ export interface CloseSessionResult {
 // src/core/utils.ts
 // All helper functions extracted from current multi-model.ts
 
-export function runCommand(command: string): Promise<{ stdout: string; stderr: string; exitCode: number }> {
+export type CommandResult = {
+  ok: boolean;
+  stdout: string;
+  stderr: string;
+};
+
+export async function runCommand(parts: string[]): Promise<CommandResult> {
   // Implementation using Bun.$
 }
 
@@ -180,7 +186,7 @@ export interface WorktreeInfo {
 
 export async function getWorktreesForSession(sessionName: string): Promise<WorktreeInfo[]> {
   // Get all worktrees and filter for this session
-  const { stdout } = await runCommand("git worktree list --porcelain");
+  const { stdout } = await runCommand(["git", "worktree", "list", "--porcelain"]);
   const worktrees: WorktreeInfo[] = [];
   
   const homedir = process.env.HOME || process.env.USERPROFILE || "/tmp";
@@ -292,8 +298,7 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
   
   try {
     // Check if session exists
-    const { exitCode } = await runCommand(`tmux has-session -t ${options.sessionName} 2>/dev/null`);
-    const sessionExists = exitCode === 0;
+    const { ok: sessionExists } = await runCommand(["tmux", "has-session", "-t", options.sessionName]);
     
     // Get list of worktrees for this session before killing tmux
     const worktrees = await getWorktreesForSession(options.sessionName);
@@ -315,7 +320,7 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
     
     // Kill tmux session if it exists
     if (sessionExists) {
-      await runCommand(`tmux kill-session -t ${options.sessionName}`);
+      await runCommand(["tmux", "kill-session", "-t", options.sessionName]);
     }
     
     let cleanupPerformed = false;
@@ -325,10 +330,10 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
       for (const worktree of worktrees) {
         try {
           // Remove worktree
-          await runCommand(`git worktree remove -f ${worktree.path}`);
+          await runCommand(["git", "worktree", "remove", "-f", worktree.path]);
           worktreesRemoved.push(worktree.path);
           
-          await runCommand(`git branch -D ${worktree.branch}`);
+          await runCommand(["git", "branch", "-D", worktree.branch]);
           branchesDeleted.push(worktree.branch);
         } catch (err) {
           console.warn(`Warning: Failed to cleanup worktree ${worktree.path}: ${err}`);
@@ -338,7 +343,7 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
       // Also remove the base directory if empty
       const worktreeBase = `~/.local/share/opencode/multi-model/${options.sessionName}`;
       try {
-        await runCommand(`rmdir ${worktreeBase} 2>/dev/null || true`);
+        await runCommand(["rmdir", worktreeBase]);
       } catch {
         // Ignore errors if directory not empty
       }