Strategic Compact Skill

Suggests manual /compact at strategic points in your workflow rather than relying on arbitrary auto-compaction.

When to Activate

• Running long sessions that approach context limits (200K+ tokens)
• Working on multi-phase tasks (research → plan → implement → test)
• Switching between unrelated tasks within the same session
• After completing a major milestone and starting new work
• When responses slow down or become less coherent (context pressure)

Why Strategic Compaction?

Auto-compaction triggers at arbitrary points:

• Often mid-task, losing important context
• No awareness of logical task boundaries
• Can interrupt complex multi-step operations

Strategic compaction at logical boundaries:

• After exploration, before execution: Compact research context, keep implementation plan
• After completing a milestone: Fresh start for next phase
• Before major context shifts: Clear exploration context before different task

How It Works

The suggest-compact.js script runs on PreToolUse (Edit/Write) and:

1. Tracks tool calls: Counts tool invocations in session
2. Threshold detection: Suggests at configurable threshold (default: 50 calls)
3. Periodic reminders: Reminds every 25 calls after threshold

Hook Setup

Add to your ~/.gemini/settings.json:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Edit",
        "hooks": [{ "type": "command", "command": "node ~/.gemini/skills/strategic-compact/suggest-compact.js" }]
      },
      {
        "matcher": "Write",
        "hooks": [{ "type": "command", "command": "node ~/.gemini/skills/strategic-compact/suggest-compact.js" }]
      }
    ]
  }
}

Configuration

Environment variables:

• COMPACT_THRESHOLD: Tool calls before first suggestion (default: 50)

Compaction Decision Guide

Use this table to decide when to compact:

Phase Transition	Compact?	Why
Research → Planning	Yes	Research context is bulky; plan is the distilled output
Planning → Implementation	Yes	Plan is in TodoWrite or a file; free up context for code
Implementation → Testing	Maybe	Keep if tests reference recent code; compact if switching focus
Debugging → Next feature	Yes	Debug traces pollute context for unrelated work
Mid-implementation	No	Losing variable names, file paths, and partial state is costly
After a failed approach	Yes	Clear the dead-end reasoning before trying a new approach

What Survives Compaction

Understanding what persists helps you compact with confidence:

Persists	Lost
GEMINI.md instructions	Intermediate reasoning and analysis
TodoWrite task list	File contents you previously read
Memory files (~/.gemini/memory/)	Multi-step conversation context
Git state (commits, branches)	Tool call history and counts
Files on disk	Nuanced user preferences stated verbally

Best Practices

1. Compact after planning: Once plan is finalized in TodoWrite, compact to start fresh
2. Compact after debugging: Clear error-resolution context before continuing
3. Don't compact mid-implementation: Preserve context for related changes
4. Read the suggestion: The hook tells you when, you decide if
5. Write before compacting: Save important context to files or memory before compacting
6. Use /compact with a summary: Add a custom message: /compact Focus on implementing auth middleware next

Related

• The Longform Guide: Token optimization section
• Memory persistence hooks: For state that survives compaction
• continuous-learning skill: Extracts patterns before session ends