⚡ ContextZip

CLI output eats your AI context window. ContextZip compresses it 40-97% (61% avg across 102 tests).
npx contextzip

🌐 Languages

한국어 • 日本語 • 中文 • Español • Português • हिन्दी • Français • Deutsch • Русский • Türkçe • Tiếng Việt

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⬇️ Install

npx contextzip

Restart Claude Code. Every command is now compressed. Zero config. macOS · Linux · Windows

Tip

Need raw output? Use contextzip proxy <command> to bypass all filters. Missing jq? Install it: brew install jq (macOS) or apt install jq (Linux). Required for the Claude Code hook.

Other install methods

# macOS / Linux
curl -fsSL https://raw.githubusercontent.com/jee599/contextzip/main/install.sh | bash
brew install jee599/tap/contextzip

# Windows (PowerShell)
npx contextzip

# Rust developers
cargo install --git https://github.com/jee599/contextzip

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👀 See the Difference

💥 Node.js Error — 30 lines → 3 lines (92% saved)

❌ Before TypeError: Cannot read properties of undefined (reading 'id') at getUserProfile (users.ts:47) at processAuth (auth.ts:12) at Layer.handle (node_modules/ express/lib/router/layer.js:95) ... 25 more node_modules lines

✅ After TypeError: Cannot read properties of undefined (reading 'id') → users.ts:47 getUserProfile() → auth.ts:12 processAuth() (+ 27 framework frames hidden) 💾 saved 92%

📦 npm install — 150 lines → 3 lines (95% saved)

❌ Before npm warn deprecated inflight@1.0.6 npm warn deprecated rimraf@3.0.2 ... 45 more deprecated warnings added 847 packages, audited 848 8 vulnerabilities (2 moderate, 6 high) ... 20 more lines

✅ After ✓ 847 packages (32s) ⚠ 8 vulnerabilities (6 high, 2 mod) ⚠ bcrypt@3.0.0: CVE-2023-31484 💾 saved 95%

🐳 Docker Build — 50 lines → 1 line (96% saved)

❌ Before Step 1/12 : FROM node:20-alpine ---> abc123def456 Step 2/12 : WORKDIR /app ---> Using cache ... 8 more steps with hashes Successfully tagged my-app:latest

✅ After ✓ built my-app:latest (12 steps, 8 cached) 💾 saved 96%

Note

Currently supports legacy Docker builder output (Step N/M format). Docker BuildKit format passes through uncompressed.

🔨 TypeScript Build — 40 errors grouped (81% saved)

❌ Before src/api/users.ts:47:5 - error TS2322: Type 'string' not assignable to 'number' ... 36 more identical errors Found 40 errors in 8 files.

✅ After TS2322: 'string' → 'number' (×40) users.ts :47, :83 orders.ts :12, :45 ... +6 files 💾 saved 81%

More examples: Rust panic, Python, Web page, ANSI, Docker failure, Java/Go

🐍 Python Traceback (72% saved) — Framework frames (flask, importlib) hidden, your code + error message kept.

🦀 Rust Panic (2-7% saved) — std::panicking, tokio::runtime frames hidden, your crate frames kept.

🌐 Web Page (73% saved) — Nav, footer, sidebar, cookie banner, social links stripped. <main>/<article> content kept.

🎨 ANSI/Spinners (83% saved) — Escape codes, spinner frames, intermediate progress bars removed. Final states kept.

🐳 Docker failure — Failed step + 2 prior steps + error message + exit code always preserved.

☕ Java — Removes java.lang.reflect, sun.reflect, org.springframework, org.apache frames.

🐹 Go — Removes runtime/, runtime.gopanic, runtime.main frames.

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📊 The Numbers Don't Lie

102 real-world tests. No cherry-picking.

Category	Tests	Avg Savings	🏆 Best	💀 Worst
🐳 Docker build	10	88%	97%	77%
🎨 ANSI/spinners	15	83%	98%	0%
💥 Error traces	20	59%	97%	-12%
🔨 Build errors	15	56%	90%	-10%
🌐 Web pages	15	43%	64%	5%
💻 CLI commands	12	42%	99%	-56%
📦 Package install	15	39%	99%	2%

Weighted total: 61% savings → 326K chars in, 127K chars out

Note

Negative = output grew. Happens on tiny inputs. We put the worst numbers in the table because hiding them would be dishonest. Full benchmark →

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🆚 Why Not Just RTK?

Built on RTK (28k⭐). All 34 RTK commands included. Plus:

	RTK	ContextZip
CLI compression (git, test, ls)	✅	✅
Error stacktraces (Node/Python/Rust/Go/Java)	❌	✅
Web page content extraction	❌	✅
ANSI / spinner / decoration removal	🟡	✅
Build error grouping (tsc/eslint/cargo)	🟡	✅
Package install noise (npm/pip/cargo)	❌	✅
Docker build compression	🟡	✅
Per-command savings display	❌	✅

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🛡️ Nothing Important Gets Lost

🔴 Error messages	ALWAYS preserved
📍 File:line in build errors	NEVER removed
🔒 Security warnings (CVE, GHSA)	ALWAYS kept
🐳 Docker failure context	ALWAYS preserved
⏎ Exit codes	ALWAYS propagated

Important

ContextZip only removes confirmed noise. When in doubt → passthrough.

🏎️ How It Works

  ┌─────────────────────────────────────────────┐
  │  Claude Code runs: git status               │
  │                         ↓                   │
  │  Hook rewrites → contextzip git status      │
  │                         ↓                   │
  │  ┌──────────────────────────────────────┐   │
  │  │ [1] ANSI preprocessor    strip junk  │   │
  │  │ [2] Command router    40+ filters    │   │
  │  │ [3] Error post-proc   compress stack │   │
  │  │ [4] SQLite tracker    record savings │   │
  │  └──────────────────────────────────────┘   │
  │                         ↓                   │
  │  Compressed output → Claude's context       │
  │  💾 contextzip: 200 → 40 tokens (80%)       │
  └─────────────────────────────────────────────┘

🔧 Commands

# Automatic (hook rewrites — no prefix needed):
git status    npm install    cargo test    docker build .

# Manual:
contextzip web https://docs.example.com    # page → content only
contextzip err node server.js              # error-focused output

# Analytics:
contextzip gain                  # dashboard
contextzip gain --by-feature     # per-filter stats
contextzip gain --graph          # daily chart

# Manage:
contextzip init --show    contextzip update    contextzip uninstall

📈 Track Everything

$ contextzip gain
📊 ContextZip Token Savings
════════════════════════════════════════
Total commands:    2,927
Tokens saved:      10.3M (89.2%)

$ contextzip gain --by-feature
Feature        Commands  Saved     Avg%
cli (RTK)      2,100     6.8M     78%
error          89        1.2M     93%
web            43        0.9M     73%
build          112       0.4M     81%

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🤝 Contribute

git clone https://github.com/jee599/contextzip.git && cd contextzip
cargo test         # 1,056 tests
cargo clippy       # lint

📡 Telemetry

ContextZip collects anonymous usage statistics (command count, savings percentage) to improve the tool. No personal data or command content is transmitted.

Disable: export CONTEXTZIP_TELEMETRY_DISABLED=1

📜 License

MIT — Fork of RTK by rtk-ai.

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⚡ Less noise. More code. Ship faster.