macOS: Ctrl+V / Cmd+V does not paste clipboard images (terminal emulator limitation)

[idanshimon]

Summary

Pasting clipboard images via Ctrl+V or Cmd+V does not work on macOS. This feature works on Windows out of the box.

Root Cause

The Copilot CLI detects image paste via an empty bracketed paste sequence (\x1B[200~\x1B[201~). On Windows, Windows Terminal emits this sequence when Ctrl+V is pressed with an image-only clipboard — triggering onEmptyPasteFallback() → ClipboardManager().getImageData().

On macOS, terminal emulators (Terminal.app, iTerm2) intercept Cmd+V at the OS level:

Clipboard content	What the terminal sends to the process
Text	Bracketed paste with the text
Image only	Nothing at all ← the problem

Ctrl+V (without Cmd) reaches the process as raw byte \x16 (ASCII 22), which is treated as a literal character — not a paste trigger.

Expected Behavior

Ctrl+V (or some keyboard shortcut) in the Copilot CLI on macOS should attach a clipboard image when one is present, matching the Windows experience.

Suggested Fix

In the key handler, detect \x16 (Ctrl+V) and check ClipboardManager().getAvailableFormats() or getImageData(). If an image is found and no text is present, proceed with the image attachment flow directly — without needing the bracketed paste sequence as intermediary.

Workaround

A community monkey-patch is available that intercepts \x16 in process.stdin.read() and injects the bracketed paste sequence when an image is on the clipboard:

👉 https://github.com/idanshimon/copilot-cli-image-paste

curl -fsSL https://raw.githubusercontent.com/idanshimon/copilot-cli-image-paste/main/patch.sh | bash

Environment

• macOS (Apple Silicon + Intel, both affected)
• Terminal.app and iTerm2 (both affected — OS-level limitation)
• Copilot CLI 1.0.40-0 (also observed on earlier versions)