yvgude/lean-ctx: README-based editorial guide

yvgude/lean-ctx describes itself in the README as "Control what your AI can see. LeanCTX (Lean Context) is the context intelligence layer for AI agents , one local Rust binary that decides what they read, remembers what they learn, guards what they touch, and proves what they save.". This article keeps to facts that can be checked in the repository. Stars, forks, and promotional badges are signals of attention, not proof of quality. Under "Control what your AI can see.", the README says: LeanCTX , Context Engineering Layer for AI Coding Agents. That establishes the project's stated boundary, not a production test.

The README's "Why developers use LeanCTX" section gives a useful starting point for deciding whether the project fits: Lower API costs , 60,90% fewer tokens on reads and shell output, cached re-reads cost 13 tokens. If that problem is not yours, popularity is a poor reason to adopt it. Project names, commands, and component names are kept as written so a reader can return to the primary source without guessing at terminology. Another checkable README item is: Longer useful coding sessions , less context waste = more room for actual code reasoning. It can shape a first test, but it does not replace testing in the intended environment.

The operating model is spread across sections such as "Control what your AI can see.". The source evidence includes: | Problem | With LeanCTX | |---------|-------------| | Repeated file reads: 2000 tokens each | Cached re-reads: 13 tokens | | Raw git status: 800 tokens | Compressed: 120 tokens | | Every turn re-sends the whole history | Proxy compresses. This article does not turn missing architecture, performance, or security details into claims. A real deployment still needs a look at the repository layout, configuration files, and release history.

Start installation from the README's documented entry point. A command that can be checked in the source is: # 1) Install (pick one) curl -fsSL https://leanctx.com/install.sh | sh # universal (no Rust needed) brew tap yvgude/lean-ctx && brew install lean-ctx # macOS / Linux npm install -g lean-ctx-bin # Node.js cargo install lean-ctx # Rust pi install npm:pi-lean-ctx # Pi Coding Agent # 2) One-command setup for your agent lean-ctx wrap cursor # or: wrap claude / wrap codex / wrap vscode # Done. Savings appea When the README contains no runnable command, this article does not invent one. Open its "Why developers use LeanCTX" section and confirm system dependencies, default ports, and first-run initialization before using a public server.