Stop burning tokens on files Claude never uses.
The average Claude Code session wastes 30-50% of tokens on files that are read but never actually used. Every Read call consumes context — whether the file was relevant or not.
- A 200-line config file? 800 tokens gone.
- A README you glanced at once? 2,400 tokens burned.
- That
package.jsonClaude reads "just in case"? 120 tokens, every time.
At $15/M tokens (Opus), a developer spending $100/month is lighting $30-50 on fire on irrelevant context.
context-optimizer silently tracks every file read, edit, and search. It learns which files are actually useful and which are waste. Over time, it builds a profile of your coding patterns and tells you exactly where your tokens go — and how to stop wasting them.
The #1 token waste in Claude Code: re-reading the same file multiple times per session. Read Cache runs as a PreToolUse hook and blocks redundant reads when the file hasn't changed.
💾 [read-cache] tracker.js is already in context (983 lines, ~9.3K tokens saved).
File unchanged — no need to re-read! Tip: use offset/limit to read a different section.
- First read: always allowed
- File modified since last read: allowed (detects via mtime)
- Different section (offset/limit): allowed if not already covered
- Agent subprocess reads: tracked separately — won't block reads in the main conversation
- Same file, same range, unchanged: blocked — saves 100% of those tokens
Typical savings: 30-60% fewer tokens per session from read deduplication alone.
Create a .contextignore file in your project root (like .gitignore) to permanently block wasteful reads. No more loading lockfiles, build output, or generated code.
# .contextignore
package-lock.json
yarn.lock
*.min.js
*.min.css
dist/**
node_modules/**
*.sql
🚫 [contextignore] package-lock.json matches pattern "package-lock.json" in .contextignore.
Use Grep to search inside, or remove the pattern from .contextignore to allow reading.
- Project-level:
.contextignorein your repo root - Global rules:
~/.claude/.contextignorefor patterns across all projects - Supports globs:
*.lock,dist/**,*.min.js,*.generated.* - Copy
.contextignore.examplefrom the plugin to get started
When your context budget reaches 80%, the plugin automatically tells Claude to run /compact instead of just showing a warning. At 90%, it becomes urgent.
[context-budget] ⚡ Auto-compact recommended — 80% budget used.
Run /compact now to free ~12.5K tokens and keep the session efficient.
[context-budget] 🔴 Critical: 90% budget used (~90K/100K tokens).
Run /compact immediately or the session will lose older context.
- Toggle with
/cco-budget auto onor/cco-budget auto off - Configurable thresholds in
budget-config.json - Smart rate-limiting — won't spam every single tool call
Every session automatically generates a summary saved to disk. Start your next session by running /cco-replay to see what was done before — no need to re-read files or guess context.
╔══════════════════════════════════════════════════════════════╗
║ RECENT SESSION SUMMARIES ║
╚══════════════════════════════════════════════════════════════╝
[1] Session Mar 24 14:30 (12 min)
Edited: src/read-cache.js, src/utils.js, README.md (3 files)
Context: 45K tokens, 12 files read, 28% waste
[2] Session Mar 24 10:15 (25 min)
Edited: src/tracker.js, src/budget.js (2 files)
Context: 82K tokens, 18 files read, 15% waste
Run /cco-anatomy to generate a compact project map. Claude reads one file instead of opening twenty to understand the codebase.
# Project Anatomy: my-app
Generated: 2024-01-15 | 45 files | ~38K tokens if all read
## Structure
| Path | Lines | ~Tokens | Type |
|------|-------|---------|------|
| src/server.ts | 450 | 4.1K | source |
| src/routes/api.ts | 280 | 2.6K | source |
...
## Heaviest files (read these with offset/limit)
1. src/server.ts — 450 lines (~4.1K tokens)
ContextShield runs as a PreToolUse hook and warns you before loading known-waste files. It checks historical patterns and suggests alternatives in real-time.
[context-shield] README.md went unused in 5 sessions (~12.4K tokens).
Use Grep to find specific content instead of full Read.
[context-shield] utils.js is usually edited with: tracker.js, budget.js.
Consider loading them together.
Run /cco-shield to see protection status and stats.
Run /cco-claudemd to analyze your CLAUDE.md for token waste: duplicates, verbose patterns, oversized code blocks, excessive whitespace. Get concrete suggestions with estimated savings.
CLAUDE.MD ANALYSIS — /project/CLAUDE.md — 342 lines | ~2.9K tokens
──────────────────────────────────────────────────────────────
⚠ 3 duplicate line(s) found (~25 saveable)
● "please make sure to" found 4x — Simplify to: "Always X" (~12 saveable)
● Code block at line 45 is 38 lines — consider shortening (~233 saveable)
○ 28% empty/separator lines — reduce for token savings (~98 saveable)
POTENTIAL SAVINGS: ~368 tokens
File patterns now have confidence scores (0.0-1.0) based on session count, usefulness consistency, and recency. High-confidence patterns produce stronger recommendations; old unused patterns decay naturally.
Run /cco-export html to generate a static HTML dashboard you can open in any browser:
- Waste trend line chart
- Token usage bar chart
- Project breakdown doughnut
- Edits-per-session timeline
Run /cco to get a visual breakdown of every file in your session. Green = useful. Red = waste.
Run /cco-report for a comprehensive dashboard: total tokens, waste ratio, cost estimates, trends, and actionable recommendations.
Run /cco-digest for a weekly efficiency grade (S/A/B/C/D/F) with breakdown by precision, edit ratio, search accuracy, and focus.
Set a token budget and get real-time warnings as you approach the limit. Auto-compact kicks in at 80%, critical alerts at 90%.
[context-budget] 70% of budget used (~70K/100K) | Est. cost: $1.050 (opus)
[context-budget] ⚡ Auto-compact recommended — 80% budget used.
[context-budget] You can free ~8.2K tokens with /compact:
drop README.md (~2.4K), tsconfig.json (~1.1K), package.json (~320)
Run /cco-git and the plugin analyzes your git diff, finds related test files, configs, and historically useful files — then suggests exactly what to load.
Create reusable context sets for different task types:
/cco-templates create bug-fix # Save files you always need for bug fixes
/cco-templates apply bug-fix # Load them instantly next timeThe plugin learns from your behavior. When you start a new task, it silently suggests files you'll probably need based on historical patterns. No configuration required.
When installed as a plugin, commands are namespaced: /claude-context-optimizer:cco. With --plugin-dir, they're also available as /cco.
| Command | Description |
|---|---|
/cco |
Session heatmap — visual file-by-file token breakdown |
/cco-report |
Full ROI report — stats, trends, waste analysis, recommendations |
/cco-digest [days] |
Efficiency digest — score, grade, cost analysis (default: 7 days) |
/cco-budget [status|set|model|auto] |
Token budget — configure limits, cost model, auto-compact |
/cco-git |
Git-aware suggestions — smart file loading based on diff |
/cco-templates [list|create|apply|delete] |
Context templates — reusable file sets for task types |
/cco-export [md|html] |
Export reports — Markdown or static HTML dashboard |
/cco-clean |
Cleanup — remove old tracking data |
/cco-shield |
ContextShield status — waste protection stats |
/cco-claudemd |
CLAUDE.md analyzer — find and fix token bloat |
/cco-anatomy |
Project anatomy — compact codebase map with file sizes and token estimates |
/cco-replay [N] |
Session replay — recent session summaries for quick context recovery |
git clone https://github.com/egorfedorov/claude-context-optimizer.git ~/claude-context-optimizer
claude --plugin-dir ~/claude-context-optimizerTo make it persistent, add to ~/.claude/settings.json:
{
"plugins": [
"~/claude-context-optimizer"
]
}This gives you full functionality: skills, auto-tracking hooks, Read Cache, ContextShield, and budget alerts.
npx skills add https://github.com/egorfedorov/claude-context-optimizerInstalls skills globally to ~/.agents/skills/ and symlinks them to Claude Code. Works with Amp, Cline, Codex, Cursor, Gemini CLI, and other compatible agents.
Note: Skills CLI installs skill prompts only. Auto-tracking hooks (Read Cache, ContextShield, budget alerts) require the plugin directory installation (Option 1) to function.
claude plugin update claude-context-optimizer@egorfedorov-pluginsThen restart Claude Code to apply the update.
- Node.js >= 18
- Claude Code (with plugin/skills support)
Once installed, the plugin works automatically — no commands needed:
Before every file re-read (Read Cache):
- Blocks re-reading files that haven't changed since last read in this session
- Allows automatically if the file was modified or a new section is requested
On session start: Weekly savings streak, warnings about consistently wasted files, auto-generated template notifications.
Before every file read (ContextShield): Checks if the file was wasted in 3+ past sessions, suggests Grep alternatives, shows co-occurrence groups.
On every file read: Warns on 3+ reads without edits (suggests offset/limit), tiered warnings for large files (200+ soft, 500+ strong).
On budget thresholds (50%, 70%, 85%, 95%): Usage percentage, cost estimates, and at 85%+ lists specific files to drop with exact token savings.
On session end: Compares waste vs recent average, updates pattern database.
After 5+ sessions: Auto-creates file templates from frequently edited files.
You literally just code. The plugin watches and helps.
You use Claude Code normally
│
▼
┌─────────────────────┐
│ PreToolUse Hook │ Read Cache: blocks re-reads of unchanged files.
│ read-cache.js │ ContextShield: warns about historically wasted files.
│ context-shield.js │
└─────────┬───────────┘
│
▼
┌─────────────────────┐
│ PostToolUse Hook │ Silent. Runs on every Read/Edit/Write/Glob/Grep/Agent.
│ tracker.js │ Records: file path, line count, token estimate, timestamp.
│ budget.js │ Tracks token accumulation, warns at thresholds.
└─────────┬───────────┘
│
▼
┌─────────────────────┐
│ Session Store │ ~/.claude-context-optimizer/sessions/<id>.json
│ Per-file tracking │ Reads, edits, usefulness score, confidence score.
└─────────┬───────────┘
│
▼
┌─────────────────────┐
│ SessionEnd Hook │ Finalizes session. Computes waste. Updates patterns DB.
│ Confidence Learning │ Patterns scored 0.0-1.0, decay over time.
└─────────┬───────────┘
│
▼
┌─────────────────────┐
│ Reports & Insights │ /cco, /cco-report, /cco-digest, /cco-claudemd
│ HTML Dashboard │ Static Chart.js analytics, open in any browser
│ ContextShield │ Proactive waste prevention before file reads
│ Smart Suggestions │ Confidence-scored recommendations
└─────────────────────┘
A file is useful if: edited after reading (+3 per edit), read multiple times (+0.5 per re-read, diminishing), or partially read with offset/limit (+1 bonus).
A file is wasted if: usefulness score is zero or negative (read but never edited, no re-reads). Large files (100+ lines) read 3+ times without edits get a penalty.
Tokens are estimated using extension-specific ratios (e.g., 3.8 chars/token for JS/TS, 4.2 for Markdown, 3.2 for JSON) applied to line counts. Not exact, but consistent enough for comparative analysis.
~/.claude-context-optimizer/
├── sessions/ # Per-session tracking data (JSON)
├── budget/ # Per-session budget state
├── templates/ # User-defined context templates
├── exports/ # Exported reports (MD/HTML)
├── read-cache/ # Per-session read cache state
├── config.json # Budget and preference settings
├── patterns.json # Cross-session file usage patterns
└── global-stats.json # Aggregate statistics
claude-context-optimizer/
├── .claude-plugin/
│ └── plugin.json # Plugin manifest
├── src/
│ ├── utils.js # Shared constants, formatting, scoring, donation info
│ ├── read-cache.js # Smart Read Cache: blocks redundant file reads
│ ├── contextignore.js # .contextignore: pattern-based file blocking
│ ├── replay.js # Session Replay: recent session summaries
│ ├── anatomy.js # Project Anatomy: compact codebase map generator
│ ├── tracker.js # Core: file & token tracking engine + session summaries
│ ├── context-shield.js # ContextShield: PreToolUse waste prevention
│ ├── claudemd-analyzer.js # CLAUDE.md token bloat analyzer
│ ├── budget.js # Token budget monitor with alerts
│ ├── digest.js # Efficiency score & weekly digest
│ ├── git-context.js # Git-aware context suggestions
│ ├── report.js # ROI report generator
│ └── export.js # Chart.js HTML dashboard exporter
├── skills/
│ ├── cco/SKILL.md # /cco — session heatmap
│ ├── cco-report/SKILL.md # /cco-report — full ROI report
│ ├── cco-digest/SKILL.md # /cco-digest — efficiency digest
│ ├── cco-budget/SKILL.md # /cco-budget — budget manager
│ ├── cco-git/SKILL.md # /cco-git — git suggestions
│ ├── cco-export/SKILL.md # /cco-export — report export
│ ├── cco-templates/SKILL.md # /cco-templates — template manager
│ ├── cco-clean/SKILL.md # /cco-clean — data cleanup
│ ├── cco-shield/SKILL.md # /cco-shield — ContextShield status
│ ├── cco-claudemd/SKILL.md # /cco-claudemd — CLAUDE.md analyzer
│ ├── cco-anatomy/SKILL.md # /cco-anatomy — project anatomy
│ └── smart-loader/SKILL.md # Auto-suggestion skill (model-invoked)
├── agents/
│ └── context-analyzer.md # Deep analysis agent
├── hooks/
│ └── hooks.json # Hook configuration
├── assets/ # SVG visuals for README
├── docs/
│ └── index.html # Landing page (GitHub Pages)
└── package.json
This plugin:
- Tracks only file paths and line counts — never file contents
- Stores everything locally in
~/.claude-context-optimizer/ - Sends zero telemetry — no network calls, no analytics, no tracking
- Can be fully wiped with
/cco-clean --reset-all
Your data never leaves your machine. Period.
Q: Does this slow down Claude Code? A: No. Hook scripts run asynchronously and typically complete in <10ms.
Q: How accurate are the token estimates? A: They use a ~4 tokens/line heuristic. Not exact, but consistent across sessions for reliable trends.
Q: Can I use this with Claude Sonnet / Haiku?
A: Yes. Set your model with /cco-budget model sonnet for accurate cost estimates.
Q: Will this work with subagents? A: Yes. The PostToolUse hook fires for all tool calls, including those made by subagents.
Q: Does Read Cache break anything? A: No. It only blocks truly redundant reads — same file, same range, no modifications since last read. If the file changed or you request a different section, the read goes through normally.
context-optimizer is 100% free and open source. No paywalls, no premium tiers, no telemetry. If it saves you money on tokens, consider supporting development:
| Chain | Address |
|---|---|
| BTC | bc1q428exz5t2h9rzk7z5ya70madh0j3rs6h4gfgyd |
| ETH (ERC-20) | 0xB3f0C8e42B7cA9d65920cEfe82e3fef1B5C9d0C9 |
| SOL | 8ctK8nt3CBkPZGfWQXX8TsnqUYUy4JAbT1EMhr8rsQxm |
PRs welcome: better token counting (AST-based), VSCode heatmap overlay, team pattern sharing, /cost integration, multi-language CLAUDE.md analysis.
MIT — do whatever you want with it.
Built with frustration at wasted tokens and love for efficiency.
If we saved you money, return the favor.