---
description: "Add support for new programming languages to Code-Graph-RAG using Tree-sitter grammars."
---

# Adding Languages

Code-Graph-RAG makes it easy to add support for any language that has a Tree-sitter grammar. The system automatically handles grammar compilation and integration.

!!! warning
    While you can add languages yourself, we recommend waiting for official full support to ensure optimal parsing quality, comprehensive feature coverage, and robust integration. [Submit a language request](https://github.com/vitali87/code-graph-rag/issues) if you need a specific language supported.

## Quick Start

Use the built-in language management tool:

```bash
cgr language add-grammar <language-name>
```

Examples:

```bash
cgr language add-grammar c-sharp
cgr language add-grammar php
cgr language add-grammar ruby
cgr language add-grammar kotlin
```

## Custom Grammar Repositories

For languages hosted outside the standard tree-sitter organisation:

```bash
cgr language add-grammar --grammar-url https://github.com/custom/tree-sitter-mylang
```

## What Happens Automatically

When you add a language, the tool automatically:

1. **Downloads the Grammar**: Clones the tree-sitter grammar repository as a git submodule
2. **Detects Configuration**: Auto-extracts language metadata from `tree-sitter.json`
3. **Analyses Node Types**: Automatically identifies AST node types for functions/methods, classes/structs, modules/files, and function calls from `node-types.json`
4. **Updates Configuration**: Adds the language to `codebase_rag/language_spec.py`
5. **Enables Parsing**: Makes the language available for codebase analysis (the grammar itself is compiled on first use by the parser loader)

## Example: Adding C# Support

```bash
$ cgr language add-grammar c-sharp
Search: Using default tree-sitter URL: https://github.com/tree-sitter/tree-sitter-c-sharp
OK Submodule added at: grammars/tree-sitter-c-sharp
Auto-detected extensions: ['.cs']
Functions: ['destructor_declaration', 'method_declaration', 'constructor_declaration']
Classes: ['struct_declaration', 'enum_declaration', 'interface_declaration', 'class_declaration']
Modules: ['compilation_unit', 'file_scoped_namespace_declaration', 'namespace_declaration']
Calls: ['invocation_expression']
OK Language 'c-sharp' added
Note: Updated codebase_rag/language_spec.py
```

## Managing Languages

```bash
cgr language list-languages

cgr language remove-language <language-name>
```

## Language Configuration

Each language is defined in the `LANGUAGE_SPECS` dict in `codebase_rag/language_spec.py`:

```python
"language-name": LanguageSpec(
    language="language-name",
    file_extensions=[".ext1", ".ext2"],
    function_node_types=["function_declaration", "method_declaration"],
    class_node_types=["class_declaration", "struct_declaration"],
    module_node_types=["compilation_unit", "source_file"],
    call_node_types=["call_expression", "method_invocation"],
),
```

## Troubleshooting

**Grammar not found**: Use a custom URL if the automatic URL doesn't work:

```bash
cgr language add-grammar --grammar-url https://github.com/custom/tree-sitter-mylang
```

**Version incompatibility**: If you get "Incompatible Language version" errors:

```bash
uv add tree-sitter@latest
```

**Missing node types**: The tool automatically detects common node patterns, but you can manually adjust the configuration in `language_spec.py` if needed.