Configuration

// babel.config.js
module.exports = {
  plugins: [
    [
      'babel-plugin-react-compiler', {
        // compiler options
      }
    ]
  ]
};

---

Compilation Control

These options control what the compiler optimizes and how it selects components and hooks to compile.

• compilationMode controls the strategy for selecting functions to compile (e.g., all functions, only annotated ones, or intelligent detection).

{
  compilationMode: 'annotation' // Only compile "use memo" functions
}

---

Version Compatibility

React version configuration ensures the compiler generates code compatible with your React version.

target specifies which React version you’re using (17, 18, or 19).

// For React 18 projects
{
  target: '18' // Also requires react-compiler-runtime package
}

---

Error Handling

These options control how the compiler responds to code that doesn’t follow the Rules of React.

panicThreshold determines whether to fail the build or skip problematic components.

// Recommended for production
{
  panicThreshold: 'none' // Skip components with errors instead of failing the build
}

---

Debugging

Logging and analysis options help you understand what the compiler is doing.

logger provides custom logging for compilation events.

{
  logger: {
    logEvent(filename, event) {
      if (event.kind === 'CompileSuccess') {
        console.log('Compiled:', filename);
      }
    }
  }
}

---

Feature Flags

Conditional compilation lets you control when optimized code is used.

gating enables runtime feature flags for A/B testing or gradual rollouts.

{
  gating: {
    source: 'my-feature-flags',
    importSpecifierName: 'isCompilerEnabled'
  }
}

---

Common Configuration Patterns

Default configuration

For most React 19 applications, the compiler works without configuration:

// babel.config.js
module.exports = {
  plugins: [
    'babel-plugin-react-compiler'
  ]
};

React 17/18 projects

Older React versions need the runtime package and target configuration:

npm install react-compiler-runtime@latest

{
  target: '18' // or '17'
}

Incremental adoption

Start with specific directories and expand gradually:

{
  compilationMode: 'annotation' // Only compile "use memo" functions
}