sessionStart and sessionEnd hooks fire per-prompt instead of per-session in interactive mode

[torumakabe]

Describe the bug

In interactive mode, sessionStart and sessionEnd hooks are triggered for each prompt/response cycle, not when the interactive session actually starts and ends. According to the documentation, these hooks should execute "when a new agent session begins" and "when the agent session completes or is terminated."

Affected version

0.0.383

Steps to reproduce the behavior

1. Create hooks.json with sessionStart and sessionEnd hooks that log to a file
2. Start Copilot CLI in interactive mode: copilot
3. Submit a prompt (e.g., "Display the current time")
4. Check the log file - observe sessionStart and sessionEnd entries
5. Submit another prompt within the same interactive session
6. Check the log file again - observe additional sessionStart and sessionEnd entries

Expected behavior

• sessionStart should fire once when the interactive session begins (copilot command executed)
• sessionEnd should fire once when the interactive session ends (user exits with /exit or Ctrl+D)
• For per-prompt logging, userPromptSubmitted hook should be used instead

Additional context

• Operating system: Linux
• CPU architecture: x86_64
• Shell: zsh

{
    "version": 1,
    "hooks": {
        "sessionStart": [{"type": "command", "bash": ".github/hooks/scripts/session-start.sh"}],
        "sessionEnd": [{"type": "command", "bash": ".github/hooks/scripts/session-end.sh"}]
    }
}

[ssfdre38]

Solution Available: Session Lifecycle Plugin

I've built a plugin that provides proper session start/end tracking!

Plugin: session-lifecycle

Live now: https://github.com/barrersoftware/copilot-plugins-registry/tree/master/plugins/session-lifecycle

What it does:

• ✅ Tracks ACTUAL session boundaries (not per-prompt)
• ✅ onActualSessionStart fires once when session truly starts
• ✅ onActualSessionEnd fires once when session truly ends
• ✅ Message counting across entire session
• ✅ Session-scoped data storage

How to use

import { PluginClient } from '@barrersoftware/copilot-plugins';

const client = new PluginClient();
await client.start();
const session = await client.createSession();

// Install plugin
await session.sendAndWait({ message: '/plugins install session-lifecycle' });

// Session start fires ONCE (not per prompt)
// Session end fires ONCE (when session actually ends)

Example Output

🔵 ═══ ACTUAL SESSION START ═══
   Session ID: abc123
   Started: 2026-01-17T08:00:00.000Z

... (many prompts)...

🔴 ═══ ACTUAL SESSION END ═══
   Duration: 325.42s
   Messages sent: 47
   Ended: 2026-01-17T08:05:25.420Z

For Developers

You can extend the plugin for custom session logic:

class MySessionPlugin extends SessionLifecyclePlugin {
  async onActualSessionStart(context) {
    await initializeDatabase();
    this.setSessionData('user', 'daniel');
  }

  async onActualSessionEnd(context, durationMs) {
    const user = this.getSessionData('user');
    await saveSessionReport(user, durationMs);
  }
}

Why a plugin?

This is a workaround while the GitHub team works on fixing the hook behavior in the CLI. The plugin:

• Provides proper session tracking NOW
• Useful for analytics, metrics, and session-based logic
• Will become obsolete if/when GitHub fixes the native hooks (that's OK!)

Testing

Would love feedback! Perfect for anyone building session analytics or needing proper lifecycle tracking.

---

Package: @barrersoftware/copilot-plugins
Registry: https://github.com/barrersoftware/copilot-plugins-registry

[VildMedPap]

How on earth is this still not resolved?

[demorgi]

Hey @stephentoub @andyfeller any timeline on this getting resolved?

[stephentoub]

This should be fixed in the next copilot CLI build.