jupyter_server_config.py

import os

PORT = int(os.environ.get("PORT", "7860"))
TOKEN = os.environ.get("JUPYTER_TOKEN", "")

c.ServerApp.ip = "0.0.0.0"
c.ServerApp.port = PORT
c.ServerApp.open_browser = False
c.ServerApp.allow_root = True
c.ServerApp.allow_remote_access = True

# Show your repo contents
c.ServerApp.root_dir = "/work"

# Make the Space load JupyterLab directly (instead of a blank / page)
# Change this path to your repo folder name if needed.
c.ServerApp.default_url = "/lab/tree/Split-Skip-and-Play"

# Allow embedding in the Hugging Face Space page iframe
c.ServerApp.tornado_settings = {
    "headers": {
        "Content-Security-Policy": "frame-ancestors *"
    }
}

# Cookies in an iframe need SameSite=None; Secure
c.ServerApp.cookie_options = {"SameSite": "None", "Secure": True}

# In iframe contexts, browsers sometimes drop the xsrf cookie; this avoids kernel-start failures.
# IMPORTANT: keep a token (JUPYTER_TOKEN) if your Space is public.
c.ServerApp.disable_check_xsrf = True

# Require token if provided (set this in Space Settings -> Secrets)
c.ServerApp.token = TOKEN