Context Manager

Context Manager

Prevent information loss when your Claude Code context window fills up. Automatically tracks usage, saves state, and restores after restart.

When to Activate

• User says /ctx or /ctx save or /ctx check
• User asks about context usage or remaining space
• User is working on a long task that might exhaust context
• Before starting a large task (reading many files, big implementation)

The Problem

Claude Code has a finite context window. When it fills up:

• The system compresses earlier messages (lossy)
• You lose working state, partial progress, and nuanced context
• Multi-step tasks break halfway through
• You repeat work you already did

Instructions

/ctx check — Check Current Usage

Read the context-usage.json file (updated by Claude Code hooks):

cat .claude/state/context-usage.json 2>/dev/null

Report to the user:

• Green (>60% remaining): Plenty of room. Work freely.
• Yellow (40-60% remaining): Getting warm. Save state before starting big tasks.
• **Red (/dev/null

If state exists:
1. Read and internalize the saved context
2. Summarize to the user: "Picking up where we left off — [task summary]"
3. Continue from "What's Next"

### `/ctx auto` — Enable Automatic Management

Set up a hook that monitors context usage and auto-saves:

Create `.claude/hooks/context-watchdog.json`:

```json
{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": { "tool_name": "*" },
        "hooks": [
          {
            "type": "command",
            "command": "node -e \"const f='.claude/state/context-usage.json';const fs=require('fs');try{const d=JSON.parse(fs.readFileSync(f));if(d.remaining_percentage .claude/state/context-usage.json

1. Add a Claude Code hook to track context usage (requires Claude Code hooks support)

1. Run your Claude Code session inside tmux for clean restart support:

tmux new-session -s claude "claude"

1. Enable /ctx auto for automatic warnings

Tips

• Save early, save often: The cost of saving is low. The cost of losing context is high.
• Restart > clear: /clear only clears history within the session. Restarting Claude Code gives a completely fresh context window.
• Front-load reading: Read all the files you'll need at the start of a task, before context fills up with working state.
• Use state files as TODO lists: "What's Next" in the state file doubles as your task list after restart.
• Checkpoint after breakthroughs: If you just figured out a tricky problem, save the insight immediately.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: RockaRhymeLLC
• Source: RockaRhymeLLC/claude-code-skills
• License: MIT

Install and usage instructions live in the source repository linked above.