At the moment TieredCompact is naive. It uses context thresholds the consumer determines and fires when those thresholds are hit. It just does different things at different threshold levels.

Your idea of using task shape to dynamically set those thresholds (or even move to model-triggered) I think is the key but is a trickier implementation. That's what I haven't gotten around to yet.

Definitely on my todo list but happy to check out a PR if you have something in mind.

Some additional info on my current public hack is also at: https://github.com/antoinezambelli/forge/blob/main/docs/USER...

Honestly probably not a PR from me right now — I'm in the middle of shipping something else — but the design idea I keep returning to is splitting the trigger into two signals:

1. Runtime-computed "context pressure" — tokens-since-last-compaction, depth of tool-call nesting, response/call ratio in recent turns. The runtime computes this; the model never sees it.

2. Model-emitted "natural breakpoint" — a tool call the model fires when it perceives it's done with a thread (file closed, task complete, branch abandoned).

Compaction fires on the AND of both. Keeps the model from compacting mid-reasoning-chain, and keeps the runtime from waiting until 90% context for the model to notice on its own.