FCM을 시작하기 위해 앱이 기기에서 백그라운드 상태일 때 특정 사용자에게 알림 메시지를 보내는 가장 단순한 사용 사례부터 살펴보겠습니다.
이 페이지에서는 설정에서 검증까지 이 작업을 수행하는 모든 단계를 제시합니다. FCM용 JavaScript 클라이언트 앱 설정을 마쳤다면 일부 단계가 이미 완료된 상태일 것입니다.
FCM에는 firebase-messaging-sw.js 파일이 필요합니다.
firebase-messaging-sw.js 파일이 아직 없다면 토큰을 가져오기 전에 이 이름으로 빈 파일을 만들어 도메인의 루트에 저장합니다.
나중에 클라이언트 설정 프로세스에서 의미 있는 내용을 파일에 추가할 수 있습니다.
다음과 같이 현재 토큰을 가져올 수 있습니다.
Web
import{getMessaging,getToken}from"firebase/messaging";// Get registration token. Initially this makes a network call, once retrieved// subsequent calls to getToken will return from cache.constmessaging=getMessaging();getToken(messaging,{vapidKey:'<YOUR_PUBLIC_VAPID_KEY_HERE>'}).then((currentToken)=>{if(currentToken){// Send the token to your server and update the UI if necessary// ...}else{// Show permission request UIconsole.log('No registration token available. Request permission to generate one.');// ...}}).catch((err)=>{console.log('An error occurred while retrieving token. ',err);// ...});
// Get registration token. Initially this makes a network call, once retrieved// subsequent calls to getToken will return from cache.messaging.getToken({vapidKey:'<YOUR_PUBLIC_VAPID_KEY_HERE>'}).then((currentToken)=>{if(currentToken){// Send the token to your server and update the UI if necessary// ...}else{// Show permission request UIconsole.log('No registration token available. Request permission to generate one.');// ...}}).catch((err)=>{console.log('An error occurred while retrieving token. ',err);// ...});
[[["이해하기 쉬움","easyToUnderstand","thumb-up"],["문제가 해결됨","solvedMyProblem","thumb-up"],["기타","otherUp","thumb-up"]],[["필요한 정보가 없음","missingTheInformationINeed","thumb-down"],["너무 복잡함/단계 수가 너무 많음","tooComplicatedTooManySteps","thumb-down"],["오래됨","outOfDate","thumb-down"],["번역 문제","translationIssue","thumb-down"],["샘플/코드 문제","samplesCodeIssue","thumb-down"],["기타","otherDown","thumb-down"]],["최종 업데이트: 2025-09-05(UTC)"],[],[],null,["To get started with FCM, build out the simplest use case: sending a\nnotification message to a specific user\nwhen the app is in the background on the device.\nThis page lists all the steps to achieve this, from setup to verification\n--- it may cover steps you already completed if you\nhave [set up a JavaScript client app](/docs/cloud-messaging/js/client)\nfor FCM.\n| **Important:** This guide focuses on the background case. If you want to receive messages when your app is in the foreground as well, see also [Receive Messages in a JavaScript Client](/docs/cloud-messaging/js/receive).\n\nSet up the SDK\n\nIf you haven't already, [add Firebase to your JavaScript project](/docs/web/setup).\n\nAccess the registration token\n\nWhen you need to retrieve the current registration token for an app instance, first\nrequest notification permissions from the user with `Notification.requestPermission()`.\nWhen called as shown, this returns a token if permission is granted or rejects the promise\nif denied:\n\n```javascript\nfunction requestPermission() {\n console.log('Requesting permission...');\n Notification.requestPermission().then((permission) =\u003e {\n if (permission === 'granted') {\n console.log('Notification permission granted.');\n```\n\n\u003cbr /\u003e\n\nFCM requires a `firebase-messaging-sw.js` file.\nUnless you already have a `firebase-messaging-sw.js` file, create an empty file\nwith that name and place it in the root of your domain before retrieving a token.\nYou can add meaningful content to the file later in the client setup process.\n\nTo retrieve the current token: \n\nWeb \n\n```javascript\nimport { getMessaging, getToken } from \"firebase/messaging\";\n\n// Get registration token. Initially this makes a network call, once retrieved\n// subsequent calls to getToken will return from cache.\nconst messaging = getMessaging();\ngetToken(messaging, { vapidKey: '\u003cYOUR_PUBLIC_VAPID_KEY_HERE\u003e' }).then((currentToken) =\u003e {\n if (currentToken) {\n // Send the token to your server and update the UI if necessary\n // ...\n } else {\n // Show permission request UI\n console.log('No registration token available. Request permission to generate one.');\n // ...\n }\n}).catch((err) =\u003e {\n console.log('An error occurred while retrieving token. ', err);\n // ...\n});https://github.com/firebase/snippets-web/blob/467eaa165dcbd9b3ab15711e76fa52237ba37f8b/snippets/messaging-next/index/messaging_get_token.js#L8-L25\n```\n\nWeb \n\n```javascript\n// Get registration token. Initially this makes a network call, once retrieved\n// subsequent calls to getToken will return from cache.\nmessaging.getToken({ vapidKey: '\u003cYOUR_PUBLIC_VAPID_KEY_HERE\u003e' }).then((currentToken) =\u003e {\n if (currentToken) {\n // Send the token to your server and update the UI if necessary\n // ...\n } else {\n // Show permission request UI\n console.log('No registration token available. Request permission to generate one.');\n // ...\n }\n}).catch((err) =\u003e {\n console.log('An error occurred while retrieving token. ', err);\n // ...\n});https://github.com/firebase/snippets-web/blob/467eaa165dcbd9b3ab15711e76fa52237ba37f8b/messaging/index.js#L27-L41\n```\n\nAfter you've obtained the token, send it to your app server and store\nit using your preferred method.\n\nSend a test notification message\n\n1. Install and run the app on the target device. On Apple devices, you'll need\n to accept the request for permission to receive remote notifications.\n\n2. Make sure the app is in the background on the device.\n\n3. In the Firebase console, open the [Messaging page](https://console.firebase.google.com/project/_/messaging/).\n\n4. If this is your first message, select **Create your first\n campaign**.\n\n 1. Select **Firebase Notification messages** and select **Create**.\n5. Otherwise, on the **Campaigns** tab, select **New campaign**\n and then **Notifications**.\n\n6. Enter the message text. All other fields are optional.\n\n7. Select **Send test message** from the right pane.\n\n8. In the field labeled **Add an FCM registration token**, enter the registration\n token you obtained in a previous section of this guide.\n\n9. Select **Test**.\n\nAfter you select **Test**, the targeted client device (with the app in\nthe background) should receive the notification.\n\nNext steps\n\nSend messages to foregrounded apps\n\nOnce you have successfully sent notification messages while your app is in\nthe background, see\n[Receive Messages in a JavaScript Client](/docs/cloud-messaging/js/receive)\nto get started sending to foregrounded apps.\n\nGo beyond notification messages\n\nTo go beyond notification messages and add other, more advanced behavior to your\napp, see:\n\n- [Receive Messages in a JavaScript Client](/docs/cloud-messaging/js/receive)\n- [Send Messages to Multiple Devices](/docs/cloud-messaging/js/send-multiple)"]]
