Using TypeScript in JavaScript modules with the ServiceNow SDK

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  • Aktualisiert 12. März 2026
  • 4 Minuten Lesedauer

    • Use TypeScript when creating JavaScript modules with the ServiceNow SDK.

    TypeScript uses static typing and type annotations to support developers catching errors earlier while writing code in Visual Studio Code.

    For general information about using TypeScript, see the TypeScript Documentation on the typescriptlang.org website.

    Use TypeScript in JavaScript modules

    Use TypeScript in JavaScript modules by adding support for TypeScript in your application.

    Vorbereitungen

    Install TypeScript version 4.8.4 or later. For installation instructions, see Download TypeScript on the typescriptlang.org website.

    Role required: admin

    Warum und wann dieser Vorgang ausgeführt wird

    Follow this procedure to update existing applications that weren't created using a TypeScript template to use TypeScript in modules if you're using ServiceNow SDK version 2.2.9 or earlier. Beginning with the ServiceNow SDK version 3.0, applications support using TypeScript in JavaScript modules by default using default compiler options. To use a tsconfig.json file with custom options for transpiling TypeScript into JavaScript during the build process, configure the tsconfigPath parameter in the now.config.json file. If you want to use a custom transpilation step before building the application, configure the modulePaths parameter in the now.config.json file.

    With the ServiceNow SDK version 2.0.1 or later, you can configure applications to use TypeScript in JavaScript modules by default with the template parameter on the now-sdk create and now-sdk convert commands. For more information, see ServiceNow SDK CLI. Follow this procedure to update existing applications to use TypeScript in modules.

    Prozedur

    1. In Visual Studio Code, open your scoped application directory.
    2. Open the application's package.json file and in the devDependencies object, add the TypeScript package and versionmake the following changes. 
      "devDependencies": {
    "typescript": "<version>",
    "@servicenow/sdk": "2.0.0",
    "@servicenow/glide": "26.0.1",
    "eslint": "8.50.0",
    "@servicenow/eslint-plugin-sdk-app-plugin": "2.0.0"
  }
      1. In the devDependencies object, add the TypeScript package and version. 
        "devDependencies": {
    "typescript": "<version>",
    "@servicenow/sdk": "2.0.0",
    "@servicenow/glide": "26.0.1",
    "eslint": "8.50.0",
    "@servicenow/eslint-plugin-sdk-app-plugin": "2.0.0"
  }
      2. In the scripts object, update the build script to compile TypeScript (.ts) modules to JavaScript (.js) for use on the instance. 
        {
    "scripts": {
        "build": "tsc -b && now-sdk build",
    }
}
    3. In your application's src/serverbase directory, add a tsconfig.json file that defines the options for compiling the application. 
      {
    "compilerOptions": {
        "rootDir": "src/server",
        "outDir": "dist/server",
        "module": "nodenext",
        "target": "es2021",
        "moduleResolution": "nodenext",
    },
    "include": ["src/**/*.ts"],
    "exclude": ["node_modules", "src/fluent/**"],
    "references": []
}
      {
    "compilerOptions": {
        "rootDir": "./",
        "outDir": "../../dist/server",
        "module": "es2022",
        "target": "es2022",
        "moduleResolution": "bundler",
        "allowJs": true,
        "declaration": false,
        "sourceMap": false,
        "skipLibCheck": true,
        "allowImportingTsExtensions": true,
        "noEmit": true
    },
    "include": [
        "./**/*.ts",
        "../../@types/**/*.modules.d.ts"
    ],
    "exclude": [
        "**/*.now.ts"
    ]
}
    4. In the application's now.config.json file, set the tsconfigPathmodulePaths parameter to the location of the tsconfig.json for JavaScript modules. map the TypeScript source files to the output modules based on your tsconfig.json. 
      {
  "scope": "x_snc_example_app",
  "scopeId": "2f8400eb07426110f736e28f69d3017a",   
  "name": "ExampleApp",
  "tsconfigPath": "./src/server/tsconfig.json"
  "modulePaths": {
      "src/server/*.ts": "dist/server/*.js"
   }
}
    5. In the src/server directory, add at least one .ts file to contain module code.
      For information about creating modules, see Create and use JavaScript modules in applications with the ServiceNow SDK.
    6. Compile TypeScript files into JavaScript modules and build your application.
      1. From your application directory, open a command-line tool on your system.
      2. Enter the following command: 
        npm run build
        now-sdk build

    Nächste Maßnahme

    Build and install the application to compile the TypeScript files into JavaScript modules and add the modules to the EcmaScript Module [sys_module] table. For more information, see Build and installdeploy an application with the ServiceNow SDK.

    Add type definitions for APIs

    Get type-ahead support for APIs and scriptable objects outside of Glide APIs.

    Vorbereitungen

    Role required: admin

    Warum und wann dieser Vorgang ausgeführt wird

    Hinweis:
    You can download type definitions for most APIs, script includes, and other scriptable objects using the now-sdk dependencies command. For more information, see Download module and script dependencies.

    Follow this procedure to manually add types definitions that the now-sdk dependencies doesn't download. You can declare modules directly in the ServiceNow SDK application to stub access to the APIs for type-ahead support. These modules aren't packaged in the application package, but they can be tracked in a source control repository for the application and shared between developers.

    Prozedur

    1. In Visual Studio Code, open your scoped application directory.
    2. In your application, add a TypeScripe (.ts) file for type definitions.
    3. In your TypeScript file, declare modules for APIs and scriptable objects.
      This example declares a module for an API using the API namespace (sn_app_api):
      declare module '@servicenow/glide/sn_app_api' {
	class AppStoreAPI {
		static canUpgradeAnyStoreApp(): boolean
	}
}
      This example declares a module to access objects defined in script includes using the scope of the script include (x_1234_scope):
      declare module '@servicenow/glide/x_1234_scope' {
	class MyLogItemClass {
		myLogFunction()
	}
}
    4. In JavaScript modules in your application, import the declared modules.
      This example imports the declared module for the AppStoreAPI.
      import { gs } from '@servicenow/glide'
import { AppStoreAPI } from '@servicenow/glide/sn_app_api'

export const canUpgradeStoreApp = function () {
	var canUpgrade = AppStoreAPI.canUpgradeAnyStoreApp()
	if (canUpgrade) {
		gs.addInfoMessage(`You can upgrade store apps!`)
	} else {
		gs.addInfoMessage(`You cannot upgrade store apps!`)
	}
}
      This example imports the declared module for the MyLogItemClass object.
      import { MyLogItemClass } from '@servicenow/glide/x_1234_scope'

export const myLogFunction = function (status) {
	const myLogItem = new MyLogItemClass()
	myLogItem.myLogFunction(status)
}
      Hinweis:
      Modules can access only global scriptable objects or scriptable objects in the same application scope.