Optional copy-on-highlight for conversation text

[bloom-street]

Request

Add an optional Copy on highlight setting for conversation text in the web/desktop client. Selecting text should copy it to the system clipboard without a separate copy command.

Proposed behavior

• Off by default; a device-local switch in Settings → General.
• Copy the final non-empty plain-text selection when a mouse drag, double/triple click, or keyboard selection finishes.
• Only copy selections entirely within conversation messages. Ignore editable inputs, the composer, and selections outside the conversation.
• Preserve the highlight and existing Cite action. Avoid repeated writes for an unchanged selection and handle unavailable clipboard access without disrupting selection.
• Support the existing clipboard fallback on plain HTTP. Native mobile support is outside this initial proposal.

This reduces repetitive copy actions when transferring excerpts from responses to another application. Because enabling it replaces the current clipboard contents whenever a selection finishes, it should remain opt-in.

Direction and scope approval

Would maintainers accept this direction and scope? Are there different selection or clipboard semantics you would prefer?

A prototype was submitted prematurely as #15857, before opening this discussion. It is linked for review of the concrete proposal; it does not have maintainer approval. I am correcting that sequencing and will follow the contribution policy before requesting acceptance of the implementation.

Prototype evidence

The prototype has selection tests and was exercised in T3's Browser panel using isolated synthetic conversation data: enable the setting, select a paragraph, then paste it into the composer without a copy command. The selection and Cite action remained available.

Recording

Prepared with GPT-6.1-Sol through the Codex harness in T3 Code.