# react-native: Compiler
URL: https://generaltranslation.com/en-US/docs/react-native/concepts/compiler.mdx
---
title: Compiler
description: How the gt CLI processes your React Native source files
---

The `gt` CLI includes a compiler that analyzes your React Native source files at build time. It catches common translation errors and can optionally automate wrapping JSX in translation components.

## Features

### Dynamic content detection
Detects unwrapped dynamic content in translation components:

```jsx
// ❌ Invalid - dynamic content not wrapped
<T>Hello {userName}</T>

// ✅ Valid - dynamic content wrapped in variable component  
<T>Hello <Var>{userName}</Var></T>
```

### Function call validation
Detects non-literal arguments passed to translation functions:

```jsx
const gt = useGT();

// ❌ Invalid - template literals and concatenation
gt(`Hello ${name}`)
gt("Hello " + name)

// ✅ Valid - string literals with variable substitution
gt("Hello, {name}!", { name })
```

## Auto JSX injection

With auto JSX injection enabled, the compiler automatically wraps translatable JSX text in translation components — so you don't need to manually add `<T>` components around every piece of text.

### Enabling auto JSX injection

Add `enableAutoJsxInjection` to your `gt.config.json`:

```json title="gt.config.json"
{
  "files": {
    "gt": {
      "output": "public/_gt/[locale].json",
      "parsingFlags": {
        "enableAutoJsxInjection": true
      }
    }
  }
}
```

### Before and after

Without auto JSX injection, you wrap text manually:

```jsx
import { T } from 'gt-react-native';

function Welcome() {
  return (
    <T>
      <Text>Welcome to our app</Text>
    </T>
  );
}
```

With auto JSX injection enabled, you write plain JSX and the compiler handles the rest:

```jsx
function Welcome() {
  return <Text>Welcome to our app</Text>;
}
```

The compiler detects the translatable text and wraps it automatically when you run `npx gt translate`.

### What the compiler respects

- **User-written `<T>` components** are left untouched — the compiler won't double-wrap your code
- **Other GT components** like `<Var>`, `<Branch>`, `<Plural>`, and `<Derive>` are also respected
- **String attributes** (e.g., `placeholder`, `alt`) are not affected — only JSX children are wrapped
- **Non-text content** like numbers and booleans is ignored