22. Compact Subsystem

Why Compacting Is a Whole Subsystem

The files under services/compact/ show that context shrinking is not one function call. There are separate pieces for microcompact, auto-compact thresholds, prompt templates, warning state, cleanup, grouping, and session-memory-aware compacting.

What microCompact.ts Reveals

Microcompact is selective. It targets specific tool outputs, estimates token pressure, manages cache edits, and keeps compacting state consistent with prompt-cache behavior. That means the goal is not only to save tokens, but to do so without wrecking cache efficiency or losing critical context.

What autoCompact.ts Reveals

Auto-compact is guarded by context-window math, feature interactions, recursion guards, and circuit-breaker logic. The system explicitly avoids compacting inside compact-related flows and certain specialized modes. This is context management as operational control flow.

Main Lesson