workbench/contrib/chat Code Organization

This contrib is, as of the end of 2025, the largest workbench contrib in VS Code by a substantial margin. Let's try to keep it organized! Here's a rough description of some of the key folders.

Key Folders

browser/

• accessibility/ - Screen reader support and accessible views.

• actions/ - All chat action registrations.

• attachments/ - Context attachment model, pickers, context widgets.

• chatContentParts/ - Rendering components for different response content types (markdown, code blocks, tool output, etc.).

• chatEditing/ - The edit session model, edit diff UI, edit snapshots.

• chatSetup/ - Placeholder registrations before the chat extentension is set up. Running the chat auth/install flow.

• contextContrib/ - The contribution point for chat context providers - note the difference from attachments/.

• widget/ - The core files related to rendering parts of the ChatWidget, including the list, the input, the model/agent pickers, and other main UI parts. Must have direct references from ChatWidget itself.

• widgetHosts/ - Hosts that embed chat widgets in other places (view pane, editor, quick chat).

common/

• chatService/ - IChatService interface, implementation, and related code.

• model/ - Chat data model, view model, and session storage.

• participants/ - Chat participant management (sometimes called "agents" in code).

• tools/ - Language model tools infrastructure and services.

  • builtinTools/ - Implementations of some built-in tools.