[FEATURE] Let side chat save its output — a single write-only "save to inbox" action
Problem
Side chat (Cmd+; / /btw) is great for asking about one part of an answer without interrupting the main session. Often that side conversation produces something worth keeping — a plan, a summary, a few hundred lines of notes.
There is currently no way to get it out except copying it and pasting it into the main conversation. That has real costs:
- the whole text now lives in the main session's context and is re-sent on every turn, although the main agent only needed it saved;
- the main agent may rephrase or trim it while writing the file;
- if the main agent is mid-turn, the paste has to wait.
And if you don't copy it in time, it's gone: side chat is not persisted, so closing it or an app update (#93122) discards it.
Why not just give side chat tools
I understand the read-only design is deliberate: a side conversation should not change the workspace while the main agent is running. I'm not asking to change that.
Proposal
Give side chat one narrow capability: save a message (or a selection) to an inbox folder.
- write-only: it can create new files in one fixed folder (e.g.
~/.claude/inbox/or a configurable path), nothing else; - no reads, no edits, no commands, no access to the project tree;
- surfaced as a button on side-chat messages ("Save to inbox") rather than a model-invoked tool, so nothing happens without the user choosing it.
The main session can then read or file an item when the user asks — the content enters its context only when it's actually needed.
This keeps the safety property (the workspace is untouched until the user decides) while removing the copy/paste round-trip.
Workaround I'm using meanwhile
Copy in side chat → a macOS hotkey saves the clipboard verbatim to ~/inbox/ → a skill in the main session lists / reads / files items on request. It works, but the copy step and the clipboard are exactly what a built-in action would remove: https://github.com/zaozhiyi/side-inbox
Related: #93122 (side chat discarded on update), #85848 (read-only sessions with exportable artifacts). Codex has the same gap: openai/codex#26227.