unable to develop teams tab app. Vite never listens on port 53000

[kale1d0code]

Vite.js never listens on localhost:53000 whenever the launch.json options are used.

To Reproduce
Steps to reproduce the behaviour:

1. Initialise a Microsoft 365 toolkit teams tab app
2. put it in a devcontainer to provide access to typescript
3. run any of the debug options (open in chrome, edge or, teams desktop)

Expected behaviour
App to be accessible on port 53000

Screenshots
If applicable, add screenshots to help explain your problem.

VS Code Extension Information (please complete the following information):

• OS: 10.0.26200 N/A Build 26200
• Version: 6.6.0

CLI Information (please complete the following information):

• OS: 10.0.26200 N/A Build 26200
• Version 6.6.0

Additional context
Add any other context about the problem here.

[m365-agent-toolkit-assistant]

👋 Hi @kale1d0code,

Thank you for reporting this issue! We want to let you know that:

⏱️ Our team will personally review your issue
🎯 You can expect a response within 2 business days

✨ This is an AI-generated initial response
🤖 AI-Generated Preliminary Analysis:

Known Issues & Troubleshooting Steps

There are several known issues related to Vite not starting on port 53000 or Teams tab app debugging failures:

1. Port conflicts (53000 already in use):

   • Port lock can occur if debug sessions end abruptly.
   • On Windows, restart the NAT service to release:

     net stop winnat
     net start winnat
     

2. Custom Domains/Ports:

   • Toolkit versions < 6.6.0 had hardcoded localhost:53000.
   • With 6.6.0, you can configure domains/ports in .env files or tasks.json.

3. Devcontainer/Debug Issues:

   • Ensure no background processes or containers are using the port (use lsof -i :53000).
   • Check launch.json, tasks.json, and .env for the correct port assignment.

4. Vite Entry Not Found or CSP Issues:

   • Check vite.config.js for correct entry (index.html) path and ensure validDomains in manifest includes required domains.

Actionable Steps:

• Restart your NAT service or check port usage.
• Confirm toolkit config (tasks.json, .env, vite.config.js) matches your intended port/domain.
• Upgrade to toolkit v6.6.0 if not already.
• If problem persists: share your launch.json, tasks.json, vite.config.js, and any error logs for deeper troubleshooting.

Reference:

• Port 53000 Issue
• Domain/Port Configuration Update

✨We'd love your feedback! Please take a moment to fill out our survey.

---

Note: This is an automated first response generated by AI. A human team member will review your issue and provide a more detailed response soon. We appreciate your patience!

[kale1d0code]

there are no port conflicts. a service never attempts to listen on port 53000 only 3978, 3979, and 39079
port 53000 was never made active. Vite claims its listening on port 3978 but I get no response from localhost:3978/tabs/home

[tecton]

Hi @kale1d0code, the port was unified to 3978 and you can open the URL https://localhost:3978/tabs/home to view it.