The thread summary
Compressing a long conversation into something the user can scan.
The user opens a thread from eleven days ago. Forty-two messages. They scroll. They look for where they stopped. They give up and start from scratch, which means the thread has failed its job. The thread summary pattern intercepts this moment with a structured recap — not of every message, but of the work that happened inside the thread.
"Returning users aren't mid-turn. They're mid-relationship. The summary is the handshake."
Goal, decided, open, last turn.
When a user opens a thread with more than a few turns, a summary renders above the latest message. Four sections, kept compact: the goal of the thread, what was decided, what's still open, what happened on the last turn. Primary action: continue. Escape hatch: fork a new thread.
Ship the Q3 pricing migration plan.
- Flat tier replaces usage-based by Q3.
- 90-day grace window for grandfathered accounts.
- Two enterprise accounts still to contact.
- Email copy needs final review.
Agreed on rollout weeks, deferred naming.
Returning users aren't mid-turn. They're mid-relationship. The summary is the handshake.
Resumption is a different cognitive task.
Starting a thread is one kind of thinking. Resuming one is another. When the user resumes, they're asking "where did I stop and what's still unresolved?" That question has a standard answer — and the product can compose it in advance, so the user doesn't have to.
Summary hygiene.
- Four slots, max. Goal, decided, open, last. More slots produce a wall of text, which is what the summary was supposed to prevent.
- Live-regenerate. The summary is derived from the thread. If the user edits a message or makes a decision, the summary updates.
- Fork button. Sometimes resuming isn't the right move. A visible way to start a new thread with related context saves the day.
The summary that's just a truncation.
Naive summaries are the first three messages, the last three messages, and a row of ellipses. The user hasn't been given a useful recap — they've been given a trailer. They still have to reconstruct the middle themselves.
What this pattern gets wrong when it gets wrong.
- Stale memory
- A persistent fact about the user that's out of date and silently poisoning answers.
- Silent truncate
- The response ran out of room or tokens and the product didn't tell the user where it stopped.
Three shipping variants worth copying.
- A collapsible spine on the left, one line per turn
- A 'summarize the last 10 turns' shortcut
- Manually-edited summary lines get a user icon