From 015f62a73b36642df779444c30fa4c86df94dca0 Mon Sep 17 00:00:00 2001
From: Layne Penney <dev@layne.pro>
Date: Sun, 25 Jan 2026 19:57:56 -0600
Subject: [PATCH] fix(orchestrate): graceful IPC disconnect to prevent race
 condition

The IPC client was using socket.destroy() which immediately closes the
socket without waiting for pending writes to complete. This caused a
race condition where:

1. Child agent sends task_complete message
2. Child immediately calls disconnect() which destroys the socket
3. Server receives 'close' event before processing the completion message
4. Reader/worker marked as "disconnected unexpectedly"

Fix: Use socket.end() with a drain wait and 1-second timeout to ensure
pending writes complete before closing the connection.

Also fixes non-interactive mode (-P flag) where readline was being
created and immediately closing, triggering premature exit before the
prompt could be processed.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 src/index.ts                  |  7 +++++--
 src/orchestrate/ipc/client.ts | 26 +++++++++++++++++++++++---
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 290f3d9..4bf2ee7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -3394,7 +3394,10 @@ Begin by analyzing the query and planning your research approach.`;
     console.log(chalk.dim('\nGoodbye!'));
   };
 
-  if (!useInkUi) {
+  // Skip readline creation for non-interactive mode
+  const isNonInteractive = Boolean(options.prompt);
+
+  if (!useInkUi && !isNonInteractive) {
     // Enable bracketed paste mode for better paste detection
     enableBracketedPaste();
 
@@ -3448,7 +3451,7 @@ Begin by analyzing the query and planning your research approach.`;
     rl.on('error', (err) => {
       logger.error(`Readline error: ${err.message}`, err);
     });
-  } else {
+  } else if (useInkUi) {
     exitApp = () => {
       inkController?.requestExit();
     };
diff --git a/src/orchestrate/ipc/client.ts b/src/orchestrate/ipc/client.ts
index 53d8154..e3afe67 100644
--- a/src/orchestrate/ipc/client.ts
+++ b/src/orchestrate/ipc/client.ts
@@ -154,13 +154,33 @@ export class IPCClient extends EventEmitter {
 
   /**
    * Disconnect from the server.
+   * Waits for pending writes to complete before closing the socket.
    */
   async disconnect(): Promise<void> {
-    if (this.socket) {
-      this.socket.destroy();
-      this.socket = null;
+    if (!this.socket) {
+      this.connected = false;
+      return;
     }
+
+    const socket = this.socket;
+    this.socket = null;
     this.connected = false;
+
+    // Wait for pending writes to drain, then close gracefully
+    await new Promise<void>((resolve) => {
+      const timeout = setTimeout(() => {
+        socket.destroy();
+        resolve();
+      }, 1000); // Timeout after 1 second
+
+      socket.once('close', () => {
+        clearTimeout(timeout);
+        resolve();
+      });
+
+      // End gracefully - allows pending writes to complete
+      socket.end();
+    });
   }
 
   /**