Hybrid Context Optimizer — Shell Hook + MCP Server. Reduces LLM token consumption by 89-99%. Single Rust binary, zero dependencies.
RustOpen Source
The problem
What's broken without this
😤
Context window fills instantly
Large codebases and verbose CLI output consume your LLM context budget before you finish describing the problem.
💸
Token costs spiral out of control
Each file read, test output, and dependency tree dump multiplies your API bills and slows down iterative development.
🔁
Repetitive context re-submission
You manually trim, summarize, and re-paste the same project structure and logs across multiple LLM conversations.
The difference
Why it matters
✗ Without
Manual work
Slow iteration
Repeated mistakes
✓ With this
Runs as single Rust binary with zero external dependencies—no Node, Python, or Docker overhead
Dual-mode operation: transparent shell hook for any CLI tool, plus 10 MCP tools for explicit editor integration
Achieves 89–99% token reduction on real workloads without requiring LLM-side prompting or model changes
Under the hood
How it works
📥
Capture CLI output or file reads
Shell hook intercepts command output; MCP server handles explicit file/dependency requests from your editor.
⚙️
Parse with tree-sitter AST
Extracts semantic structure from 14 languages, strips whitespace and comments, encodes via Token Dense Dialect (TDD) to compress syntax trees by 70–90%.
📤
Send compressed context to LLM
Editor receives dense, structured output that preserves code meaning in 1–11% of original tokens.
What it does
Core capabilities
⚡
Fast
Optimized for speed and efficiency.
🎯
Reliable
Built to work consistently.
🔌
Integrates
Works with your existing tools.
I stopped manually copying file trees into Claude because lean-ctx compresses my entire project structure into a few hundred tokens—and my editor sees it automatically.
arc-web/diet-claude
Codebase
Built with care
💻
Rust
Built in Rust for type safety and reliability.
🏗️
Architecture
MCP Server
📦
Key deps
rmcp, tiktoken-rs, tokio
🔓
Open Source (MIT / PolyForm)
Fork it, extend it, ship it. It's yours.
Built by
Mike Ensor Arc Web
AI automation, marketing technology, building tools that work.
Mike builds open-source AI tools for agencies, marketers, and operators who are done waiting for software to catch up. All Arc Web projects are open source by default — fork them, extend them, ship them.