#server.tsconfigPath

• Type: string
• Default: <appDirectory>/tsconfig.json

Specifies the tsconfig file used by server-side TypeScript processes.

This option affects:

• BFF / API compilation (@modern-js/plugin-bff)
• Custom server compilation (*.ts files under server/)
• Runtime ts-node registration, such as SSR, modern.config.ts, and .ts files under config/

When this option is not set, <appDirectory>/tsconfig.json is used by default.

#When to use

Use this option when frontend and server-side code need different TypeScript configurations.

For example, the frontend can use moduleResolution: "Bundler", while the server side uses moduleResolution: "NodeNext" for type resolution of conditional exports or subpath exports.

#Example

The example below uses tsconfig.server.json as the file name. You can use another name in your project.

Add <appDirectory>/tsconfig.server.json:

{
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "target": "ES2022",
    "lib": ["ESNext"],
    "types": ["node"],
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  },
  "include": ["api", "shared", "server", "config", "modern.config.ts"]
}

Specify this file in modern.config.ts:

export default defineConfig({
  server: {
    tsconfigPath: './tsconfig.server.json',
  },
});

#Notes

• tsconfigPath is resolved relative to appDirectory. Absolute paths are also supported.
• It is recommended to inherit shared options such as paths from the root tsconfig through extends, instead of maintaining them in multiple files.
• If the configured file does not exist, TypeScript / ts-node will throw an error at startup.