The Chat Doctor: what it checks and how it heads off chat problems

Anyone who's chatted with a language model long enough knows the feeling: a chat starts repeating itself, or a reply cuts off strangely. The Chat Doctor is our attempt to not just shrug that off, but to make it visible — and fixable.

Five warning signs, spotted entirely offline

After every reply, a small, purely local heuristic checks five things: 20-word repetitions within the reply, an unusual share of broken characters, a sudden script switch, an abnormal length deviation, and a closing sentence that keeps repeating across replies. For the script check, we compare against your own recent genuine replies — so a Japanese or Cyrillic chat isn't flagged just for not being Latin script. None of this leaves your device; none of it touches a server.

A quiet line, never an alarm

If the combination of the five signals looks off, you see a calm, small hint line in the chat — no popup, no interruption. If a provider itself cuts a reply off with an error, we show the Chat Doctor invitation regardless of the score, because that's almost always a real problem. You can mute the hint line for a single chat, or turn it off entirely in settings — on by default, but it's your call.

Repairing means suggesting, never intervening automatically

The actual analysis run is free, offline, and looks at your chat's recent messages. The doctor knows five possible actions, from a cleanup rule to a re-anchor that reminds the model what a normal conversational tone looks like. None of it happens automatically: you get a report, you choose, and only an explicit apply click changes anything. Even then the doctor never deletes your message text — cleanup rules get disabled, not deleted, so you can switch them back on later.

Undoable, even afterward

Every repair run can be undone — the last run per chat, not just right after it happened. Trying to undo the same run a second time returns a clear error instead of silently doing nothing. One deliberate exception: if you branch a problematic chat off to edit it, the branch counts as its own chat — you undo that the same way as any other chat, by deleting it, not through the doctor's undo.

The doctor makes a diagnosis. What happens next is your call — and every bit of it can be undone.