`hs project dev` cannot connect to a project

[JanHranicky]

Hi,

I encountered similiar issue to this one. I am trying to develop a HubSpot extension, but HubSpot’s CLI command `hs project dev` doesn’t seem to be working for me. After setting up the project and uploading it to my account, I run `hs project dev` and the following window opens:

The extension is installed in the account. While trying to find a solution, I also noticed that running `hs project dev` without the extension being installed prompts you to install it. However, when I do it this way, the command gets stuck in an infinite loop waiting for the extension to be installed.
Installing the extension using `hs project dev`:

I’m not sure if the problem is related.

Thanks, any help is appreciated!

[Jaycee_Lewis]

Hey, @JanHranicky Were you able to make progress? If not, please let me know and we can try to tag in some of our community experts. — Jaycee

[JanHranicky]

Hey, @Jaycee_Lewis. Unfortunately no, did not make any progress on this

[Berangere]

Hi @JanHranicky and thank you so much for reaching out and for your prompt reply!

I wanted to share a few resources that might be helpful:
- Create UI Extensions in your project-built private app
- Projects and sandboxes CLI reference
- Local Development Troubleshooting
To ensure you have the best support, I’d love to bring in our amazing experts. Hi @Anton, @RSchweighart and @SteveHTM do you have any tips or guidance to assist @JanHranicky further, please?
Wishing everyone a wonderful day, and thank you all so much for your help!
Bérangère

[vilsk]

Hi all, I’m running into the same issue with hs project dev not connecting to the project. I’m on a Debian 13 LXC container with Node.js 22, and I can’t see any obvious error why the HubSpot CLI isn’t establishing the connection. Here’s what I’ve checked so far:
• Node.js v22 (supported according to the CLI docs)
• Latest HubSpot CLI installed (hs --version confirms it)
• The project is already installed in my HubSpot account
• Auth (hs auth) is completed and linked to the correct account
Yet hs project dev still won’t connect or stays stuck. Does anyone have new suggestions or specific checks I should try (e.g., firewall/WebSocket issues, project config in hsproject.json, CLI vs platform version mismatches)?
Thanks a lot!
Soren

[JanHranicky]

Hi Soren,
I managed to solve my issue by allowing permission for `app.hubspot.com` in my browser. There should be a popup first time you run `hs project dev`, which then never appears again. If you ignore it, there’s a good chance you’ll get stuck.
There is a warning in the docs I found after solving my issue about this popup Projects and sandboxes CLI reference - HubSpot docs

Try checking/allowing the permission and pray it works
Gl,
Jan

[vilsk]

Hi Jan,

thank you for your answer.
I´m using firefox .. maybe thats the reason? Or do i need a local installation?

[vilsk]

Thank you all for your help.
Found a solution ..
It needs a port-mapping: 5173:127.0.0.1:5173 -L 8080:127.0.0.1:8080 -L 35177:127.0.0.1:35177’
Then its possible to use an LXC
Hope that could helps others with same problems ..
best reg.
Soren