Odd compaction behavior

[shaunpatel]

I'm noticing that when the auto-compaction gets triggered at 50%, it doesn't actually clear the tokens. It might reduce the percentage down to 40% or so, about 10%. This creates a strange feedback loop where the auto-compaction gets triggered very quickly. If I manually run this/compact, it reduces it down to 1 or 2%, as expected.

[vtemian]

Thanks for reporting this, @shaunpatel! Your detailed description of the feedback loop behavior was key to tracking this down.

Fixed in v0.8.3

The issue had two root causes:

1. Missing event: The session.compacted event is defined in the SDK but never emitted by OpenCode. We now listen for message.updated with summary: true instead, which fires when the summary message is created.

2. Race condition: The compaction listener was set up after calling summarize(), so fast compactions could complete before we started listening. Now we set up the listener first.

The auto-compaction now properly waits for summarization to complete before allowing new messages, so context should drop to <10% as expected.

Let us know if you run into any other issues!