RunBlue Matter: Set API Key from the Command Palette (Cmd+Shift+P).
Features
Explain Selected Code — Select any code block and press Cmd+Shift+E (Mac) / Ctrl+Shift+E (Windows/Linux). An explanation appears in a side panel instantly.
Inline CodeLens — "Explain" button appears above your selection. Click to explain without using the keyboard shortcut.
Jupyter notebook support — Works inside .ipynb notebook cells. Blue Matter automatically includes context from earlier cells (imports, variables, functions) so explanations reference what was defined previously.
Python cell mode — Works in .py files that use # %% cell markers (VS Code Python Interactive Window / Jupyter-style cells).
From cache — Previously explained code loads instantly from a local cache with no API call.
Annotations — Add your own notes to code blocks with Cmd+Shift+N. Search them later with Blue Matter: Search Annotations.
Workspace indexing — Blue Matter indexes your repo's symbols and imports (including .ipynb notebooks) to give richer, context-aware explanations.
Keyboard Shortcuts
Command
Mac
Windows / Linux
Explain Selected Code
Cmd+Shift+E
Ctrl+Shift+E
Add Annotation
Cmd+Shift+N
Ctrl+Shift+N
Privacy
In standard mode, selected code is sent to OpenRouter's API for AI processing. OpenRouter's privacy policy applies.
In strict mode (Settings → Blue Matter: Privacy Mode → strict), all AI calls are disabled — only previously cached explanations are shown. No code ever leaves your machine.
Your API key is stored in your OS keychain via VS Code SecretStorage and is never written to settings files or logs.
