CDF hosted Streamlit apps failing due to missing "ssl" dependency

Update timeline

1. investigating Aug 24, 2026, 01:52 PM UTC

   We are investigating issues with CDF-hosted Streamlit apps, where apps get the error ModuleNotFoundError: No module named 'ssl' We are investigating the issue. The issue can affect all users of Streamlit apps regardless of which CDF clusters they are hosted in. In the meantime, explicitly adding the "ssl" module to your app's Python requirements can fix the immediate problem and is worth trying as a workaround. Note: CDF-hosted Streamlit apps are in public preview: https://docs.cognite.com/cdf/streamlit/index#streamlit-apps and are not yet in production: https://docs.cognite.com/cdf/product_feature_status#public-preview.

2. identified Aug 25, 2026, 07:44 AM UTC

   The issue leading to the ModuleNotFoundError: No module named 'ssl' error in Streamlit apps has been identified as a change in a third party library, specifically the Microsoft Authentication Library for Python (MSAL). MSAL is commonly used in conjuction with the Cognite SDK to handle authentication. MSAL version 1.38, released on 2026-08-24, references the ssl module without declaring a dependency on it. This works on ordinary CPython installations because that environment includes the ssl module by default. However, Streamlit in the browser uses the Pyodide runtime environment. Pyodide does not include the ssl module by default. This leads to failures when the latest MSAL library is used in Streamlit apps. The engineering team is currently adding a workaround to the Cognite Streamlit runtime environment setup to ensure that the ssl module is always present.

3. monitoring Aug 27, 2026, 11:06 AM UTC

   We have successfully resolved the underlying deployment issue. Our engineering team corrected the production deployment configuration, ensuring it now points to the correct Firebase project and hosting site. The fix has been verified across multiple production clusters and confirmed to be working as expected. If you had previously applied the temporary workaround of adding ssl to your application's INSTALLED PACKAGES, no further action is needed this entry can remain in place and will not interfere with the platform fix.

4. resolved Aug 31, 2026, 12:07 PM UTC

   The issue got fixed on 27th August. All Apps are now up and running.