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│ * Welcome to the Rune context index ! │
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Repository Context Protocol
Git stores history. Rune stores understanding.
Rune scans your repository and generates RUNE.md — a single skill file that any AI coding agent can read to understand your codebase. No MCP server needed. No configuration. Just a file.
Works with Antigravity · Claude · Cursor · Codex · Windsurf · Copilot and any agent that reads project files.
Install
Linux / macOS:
curl -fsSL https://raw.githubusercontent.com/rune-context/rune/main/install.sh | sh
Windows:
irm https://raw.githubusercontent.com/rune-context/rune/main/install.ps1 | iex
From source:
git clone https://github.com/rune-context/rune.git
cd rune
make install
Quick Start
cd your-project
rune init # Create .rune/ config
rune index # Scan and generate RUNE.md
That's it. Your AI agents will now read RUNE.md automatically.
What RUNE.md Contains
A single, human-readable markdown file with:
- Architecture — languages, file counts, line counts, structure
- File Tree — visual directory tree
- File Map — every file with its exports and dependencies
- Dependencies — what imports what
- Key Exports — all public functions, types, classes
Example output:
## Architecture
**24 files** · **3774 lines**
Languages:
- go (15 files)
- typescript (8 files)
Structure:
- internal/: 9 files
- cmd/: 5 files
## File Map
### cmd/
- `cmd/index.go` (go, 73 lines) → Index
- `cmd/init.go` (go, 70 lines) → Init
## Key Exports
**internal/scanner/scanner.go**
- `FileInfo`
- `Scanner`
- `New`
Commands
| Command | Description |
|---|---|
rune init | Initialize .rune/ config |
rune index | Full scan → generates RUNE.md |
rune update | Incremental update of RUNE.md |
rune context <query> | Get targeted context (stdout) |
rune doctor | Check repository health |
rune serve | Start MCP server (optional, stdio) |
How Agents Use It
AI coding agents automatically discover and read project files like RUNE.md. No special setup needed:
| Agent | How it reads RUNE.md |
|---|---|
| Antigravity | Reads project files automatically |
| Claude Code | Reads project files in workspace |
| Cursor | Reads .md files in project root |
| Codex | Reads project context files |
| Windsurf | Reads project files automatically |
| Copilot | Reads via @workspace context |
For agents that support MCP, you can optionally run rune serve for richer tool-based access.
Customize
Edit .rune/spec.md to add a project description:
# My Project
A REST API for managing user accounts.
Backend: Go with Gin
Database: PostgreSQL
Auth: JWT tokens
Edit .rune/conventions.md to add coding rules:
# Conventions
- Use repository pattern for data access
- Never use raw SQL, use sqlc
- All endpoints return JSON
- Tests required for all handlers
Both files are included in the generated RUNE.md.
[!NOTE] Ownership & LLM Updates
- Human-authored: These files are intended to be human-authored guardrails. Rune is local-first and offline; it will never automatically overwrite or modify these files during
rune updateorrune index.- Agent updates: AI coding agents should avoid modifying these files unless you explicitly instruct them to document a new architectural decision or project convention.
Supported Languages
Rune extracts imports, exports, and dependencies from:
Go · Python · JavaScript · TypeScript · Rust · Java · Kotlin · Ruby · PHP · C/C++ · C# · Swift · Dart · Lua · Scala · Elixir · Erlang · Zig · Vue · Svelte
Performance
| Metric | Target |
|---|---|
| Cold index (10k files) | < 30s |
| Incremental update | < 1s |
| Startup | < 100ms |
| Memory | < 200MB |
Design
- Single binary — no runtime dependencies
- Single output — one
RUNE.mdfile - Local-first — no login, no cloud, fully offline
- Language-agnostic — works with any language
- Incremental — only re-scans changed files
- Human-readable —
RUNE.mdis plain markdown
Support
Rune Ctx is, and always will be, completely free and open-source. If you find it useful and want to support its continued development, you can buy me a coffee!
License
