# LeanCTX — Full Documentation Index

> LeanCTX (short for Lean Context) is the open-source context engineering layer for AI agents. It decides what agents read, compresses what they send, remembers what they learn, guards what they touch, proves what they save, and replays what they saw. 60–90% fewer tokens as the receipt. Single Rust binary, 30+ AI tools, zero telemetry. Version 3.9.3.

## Documentation

- [Getting Started](https://leanctx.com/docs/getting-started/): Installation, setup, and first steps
- [Configuration](https://leanctx.com/docs/configuration/): config.toml, security, environment variables, hooks
- [Tool API Reference](https://leanctx.com/docs/tools/): All 81 MCP tools with schemas and examples
- [CLI Reference](https://leanctx.com/docs/cli-reference/): Terminal commands and flags
- [Quick Reference](https://leanctx.com/docs/quick-reference/): Daily workflow cheat sheet
- [Security](https://leanctx.com/docs/security/): PathJail, shell allowlist, sandbox, roles, secret detection
- [Budgets & SLOs](https://leanctx.com/docs/budgets-and-slos/): Token/cost budgets and service level objectives
- [Observatory](https://leanctx.com/docs/observatory/): Real-time dashboard and analytics
- [Changelog](https://leanctx.com/docs/changelog/): Version history with detailed release notes

## Features

- [How It Works](https://leanctx.com/how-it-works/): Data flow, compression pipeline, quality preservation
- [Architecture](https://leanctx.com/architecture/): The Cognitive Context Layer — architecture and capabilities
- [Compatibility](https://leanctx.com/compatibility/): 30+ AI coding tools with setup commands

## Concepts

- [Read Modes](https://leanctx.com/docs/concepts/read-modes/): 10 modes for different file reading strategies
- [Token Savings](https://leanctx.com/docs/concepts/token-savings/): How compression works and what it saves
- [Protocols](https://leanctx.com/docs/concepts/protocols/): CEP, CCP, and TDD communication protocols

## Tool Categories

- [Core Tools](https://leanctx.com/docs/tools/core/): ctx_read, ctx_shell, ctx_search, ctx_tree, ctx_overview, ctx_multi_read, ctx_expand, ctx_preload, ctx_prefetch, ctx_delta, ctx_dedup, ctx_compress, ctx_fill, ctx_context, ctx_provider, ctx_cache
- [Session Tools](https://leanctx.com/docs/tools/session/): ctx_session, ctx_agent, ctx_handoff, ctx_share
- [Memory Tools](https://leanctx.com/docs/tools/memory/): ctx_knowledge, ctx_compress_memory
- [Intelligence Tools](https://leanctx.com/docs/tools/intelligence/): ctx_intent, ctx_graph, ctx_graph_diagram, ctx_index, ctx_symbol, ctx_impact, ctx_callers, ctx_callees, ctx_callgraph, ctx_semantic_search, ctx_discover, ctx_discover_tools
- [Analysis Tools](https://leanctx.com/docs/tools/analysis/): ctx_architecture, ctx_analyze, ctx_smells, ctx_review, ctx_outline, ctx_routes, ctx_benchmark, ctx_metrics, ctx_cost, ctx_heatmap, ctx_gain
- [Workflow Tools](https://leanctx.com/docs/tools/workflow/): ctx_workflow, ctx_task, ctx_verify, ctx_proof, ctx_execute, ctx_pack, ctx_wrapped, ctx_call, ctx_response, ctx_feedback, ctx_artifacts

## API

- [MCP Tools Manifest](https://leanctx.com/generated/mcp-tools.json): Machine-readable tool schemas (JSON)
- [API Reference](https://leanctx.com/docs/api-reference/): HTTP API documentation

## Resources

- [GitHub Repository](https://github.com/yvgude/lean-ctx): Source code, issues, discussions
- [npm Package](https://www.npmjs.com/package/lean-ctx-bin): Binary distribution
- [crates.io](https://crates.io/crates/lean-ctx): Rust crate
- [Pi Package](https://pi.dev/packages/pi-lean-ctx): Pi.dev distribution
- [AUR Package](https://aur.archlinux.org/packages/lean-ctx): Arch Linux
- [Homebrew](https://github.com/yvgude/homebrew-lean-ctx): macOS/Linux via Homebrew
- [Discord](https://discord.gg/pTHkG9Hew9): Community and support
- [Privacy Policy](https://leanctx.com/privacy/): Data handling
- [Terms of Service](https://leanctx.com/terms/): Usage terms

## When NOT to use LeanCTX

LeanCTX is deliberately scoped. It is honestly **not** the right fit when:

- **Tiny codebases or one-off questions** — context savings are marginal; LeanCTX pays off on real multi-file codebases and longer agent sessions.
- **You want a hosted SaaS or GUI dashboard** — it is a local-first single binary with zero telemetry; everything runs on your machine.
- **A turnkey enterprise document-search / RAG platform** — `ctx_index` ingests a mixed *local* corpus (code plus PDF, HTML, CSV/TSV, EML, JSON/NDJSON) for agent context, but LeanCTX is not a managed vector-database or document-search product for large non-code archives.
- **AI tools that support neither shell nor MCP** — integration needs CLI-redirect, MCP, or a hybrid of both.
- **A replacement for your coding agent** — LeanCTX is a context layer; it shapes what the model sees, it does not plan or write code. Use it *with* Cursor, Claude Code, Copilot, or Windsurf.

## Optional

- [Home](https://leanctx.com/): Overview and quick start
- [What is Context Engineering?](https://leanctx.com/what-is-context-engineering/): Concept explainer
- [Comparison](https://leanctx.com/compare/): Feature comparison with alternatives