fable-agent/PHASES/phase-02-context-manager.md

Phase 2: Context Manager

Purpose: Sliding window with summarization and priority-based pruning. TS Module: src/tier1-foundation/context-manager.ts

What It Does

Manages the agent's context window within budget constraints.

When the budget is exceeded:

1. Summarize lowest-priority entries (oldest 30% by priority score)
2. Drop entries that have already been summarized and remain low-priority
3. Never drop critical priority entries

Priority Levels

Priority	Weight	When to Use
critical	100	Current goal, task definition, rubric
high	50	Recent observations, active state
normal	10	Skill contents, historical context
low	1	Archived iterations, verbose logs

Usage

Context is managed automatically by the feedback loop. Add key information explicitly when needed via the TS engine or by writing directly to the context window.