Codex Desktop on macOS: app becomes unresponsive after pasting very long text into message input

What version of the Codex App are you using (From “About Codex” dialog)?

26.602.40724

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Darwin 25.5.0 arm64 arm

What issue are you seeing?

When I paste a very long text block into the Codex message input area, Codex becomes completely unresponsive. The whole application stops responding.

The only recovery path I found was to force quit Codex and restart it.

What steps can reproduce the bug?

1. Open Codex Desktop on macOS.
2. Focus the message input area.
3. Paste a very long text block into the input area.
4. Observe that the app becomes unresponsive.

What is the expected behavior?

Codex should remain responsive after pasting a very long text block into the message input area.

The expected behavior should be one of the following:

1. Codex accepts the pasted content directly as text input in the message composer.
2. If the pasted content is too large for the composer, Codex automatically appends the content to the conversation as a .txt attachment.
3. If neither is possible, Codex shows a clear validation message explaining that the pasted content is too large, without freezing the app.

Additional information

This looks like a composer/input-size/rendering/performance issue. Pasting a large text payload into the message composer should not hang the entire desktop application.

For large pasted text, automatically treating the content as a .txt attachment would be a useful fallback behavior and would avoid blocking the UI.