File Attachments in Chat Input

Priority: P2 Issue: #6078

Image attachments and @file path mentions work. Non-image file content attachments are missing.

Supported Image Types

The following image formats are supported for paste and drag-and-drop:

• PNG (image/png)
• JPEG (image/jpeg)
• GIF (image/gif)
• WebP (image/webp)

Drag-and-Drop (Shift Required)

VS Code disables webview pointer-events during drag operations so it can handle drops in the editor area. To drop images into the chat input, hold Shift while dragging. This re-enables the webview to receive drop events (VS Code 1.91+, see microsoft/vscode#182449).

Remaining Work

• Add a file attachment button to the chat input toolbar (paperclip icon or similar)
• Support drag-and-drop of non-image files onto the chat input area
• Support a file picker dialog via the button
• For text-based files: read content and include as a text part in the message
• For binary files: show an unsupported notice
• Show attached files as chips/tags above the input with remove button
• Limit attachment size with a clear error if exceeded