Extension fails to activate in Cursor

[ag-gusto]

Environment data

• VS Code version: Cursor 2.1.17 (VS Code fork)
• Deepnote Extension version (available under the Extensions sidebar): 1.2.0
• OS (Windows | Mac | Linux distro) and version: macOS 15.7.1 (Sequoia)
• Python and/or Anaconda version: Python 3.9.6

Expected behaviour

When opening a .deepnote file, it should open in the notebook editor with the Deepnote UI, allowing me to run cells and interact with the notebook.

Actual behaviour

The extension fails to activate entirely. When attempting to open a .deepnote file, Cursor shows "Unable to open" with an option to "Open in text editor". The file opens as raw JSON instead of a notebook.

The extension host log shows:

Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'vscode' imported from 
~/.cursor/extensions/deepnote.vscode-deepnote-1.2.0-universal/dist/extension.node.proxy.js

Steps to reproduce:

1. Install Cursor IDE (VS Code fork)
2. Install the Deepnote extension v1.2.0 from the marketplace
3. Create or open any .deepnote file
4. Observe that the extension fails to activate and the file cannot be opened as a notebook

Logs

Output for Deepnote in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Deepnote)

2025-12-09 15:39:31.517 [info] ExtensionService#_doActivateExtension ms-toolsai.jupyter-renderers, startup: false, activationEvent: 'onNotebookSerializer:deepnote', root cause: Deepnote.vscode-deepnote
2025-12-09 15:39:31.520 [info] ExtensionService#_doActivateExtension Deepnote.vscode-deepnote, startup: false, activationEvent: 'onNotebookSerializer:deepnote'
2025-12-09 15:39:31.524 [error] Activating extension Deepnote.vscode-deepnote failed due to an error:
2025-12-09 15:39:31.524 [error] Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'vscode' imported from /Users/arthur.gonzalez/.cursor/extensions/deepnote.vscode-deepnote-1.2.0-universal/dist/extension.node.proxy.js
    at Object.getPackageJSONURL (node:internal/modules/package_json_reader:266:9)
    at packageResolve (node:internal/modules/esm/resolve:779:81)

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Note: This appears to be an ES module resolution issue in extension.node.proxy.js where the vscode package import fails in Cursor's extension host environment. The extension may work in standard VS Code but fails in VS Code forks like Cursor.