Chatbot won't drop the old topic

Same bot, brand new question, and it's still stuck on the topic from five minutes ago.

Beginner to intermediateRead 5 minDoing: a few hours7 steps

▶ Start

What you'll have at the end

A chat that answers a new question cleanly instead of dragging in leftover context from a topic you already left.

Before you start

You need

You have a multi-turn chatbot that keeps some state between turns, recent messages, looked-up facts, or both, and sends that state back to the model on every call.

Not covered

Trimming history because the conversation is running long for the token budget is a separate technique, covered by the recipe on compacting old turns; this only covers dropping the old topic's facts because the topic itself changed, at any length.

Leans on

7 steps

Where to go next

Compact old turns before your context window overflows

go there when the conversation is simply getting too long for the token budget, not when the topic itself has changed

Checked 15 Aug 2026

Part of the Context Engineering cookbook