kakehashi is a Tree-sitter-based language server that bridges the gap between languages, editors, and tooling.
┌─────────────┐ ┌─────────────┐
│ │◄── Syntax Highlight ───►│ Editor │
│ kakehashi │◄── Selection Range ───►│ (Any LSP │
│ │◄── Go-to Definition ───►│ Client) │
│ │◄── ... ───►│ │
└────▲─▲─▲────┘ └─────────────┘
│ │ │
┌────▼─▼─▼────┐
│ External │
│ Language │
│ Servers │
│ (Optional) │
└─────────────┘
kakehashi（架け橋）means "bridge" in Japanese — and that's exactly what this language server does:
Tree-sitter grammars work everywhere. By leveraging Tree-sitter for parsing, kakehashi provides consistent syntax highlighting, selection ranges, and more across any editor that supports LSP and any language with a Tree-sitter grammar.
No more fragmented tooling per editor or language.
Markdown with code blocks? HTML with inline JavaScript? kakehashi detects these injection regions and can:
- Provide Tree-sitter features directly — semantic tokens and selection ranges work inside embedded code
- Delegate to external language servers — go-to-definition, hover, completion, etc. are forwarded to the appropriate language server (e.g., rust-analyzer for Rust code blocks)
This "virtual file" bridging lets you get full IDE features even inside embedded code.
| Feature | Host | Injection | Bridge |
|---|---|---|---|
| Semantic Tokens | ✅ | ✅ | — |
| Selection Range | ✅ | ✅ | — |
| Go-to Definition | — | — | ✅ |
| Go-to Type Definition | — | — | ✅ |
| Go-to Implementation | — | — | ✅ |
| Go-to Declaration | — | — | ✅ |
| Hover | — | — | ✅ |
| Completion | — | — | ✅ |
| Signature Help | — | — | ✅ |
| Find References | — | — | ✅ |
- Host: Features for the main document language
- Injection: Features for embedded language regions
- Bridge: Features delegated to external language servers
Download the latest release for your platform from GitHub Releases.
Prepare the following, and kakehashi will auto-install Tree-sitter parsers and queries as needed:
- tree-sitter CLI
- Git
- C compiler
See docs/README.md for detailed setup instructions for various editors.
make deps/nvim
nvim -u scripts/minimal_init.luaTraditional language servers are language-specific. Tree-sitter parsers are fast and universal, but historically lacked the "smart" features. kakehashi bridges both worlds:
- Universal parsing via Tree-sitter
- Smart features via LSP bridge to specialized language servers
- Editor-agnostic — works with any LSP client
Whether you're editing a Markdown document with embedded Rust, or an HTML file with inline CSS and JavaScript, kakehashi acts as the 架け橋 (bridge) that connects everything together.
MIT