Cloud Firestore を使って kintone へ プッシュ通知する https://blog.r3it.com/cloud-firestore-with-kintone-aaa50fcea1c7

firestore_on_kintone.js

(function () {
  "use strict";

  firebase.initializeApp({
    apiKey: "XXxxXxXXXx99x9XX-xxx_xxXxXXXXXXxXXxXXxX",
    authDomain: "projectId.firebaseapp.com",
    projectId: "projectId"
  });

  // Initialize Cloud Firestore through Firebase
  var db = firebase.firestore();

  kintone.events.on("app.record.index.show", function (e) {

    db.collection("users").doc("user1").collection("documents")
      .onSnapshot(function (snapshot) {
        if (snapshot.docChanges.length != snapshot.docs.length) {
          snapshot.docChanges.forEach(function (item) {
            var doc = item.doc;
            var data = doc.data();
            console.log(doc.id, " => ", data["content"]);
            swal({
              title: data["content"],
              text: "",
              timer: 5000
            }).then(function () { }, function (dismiss) { });
          });
        }
      }, function (error) {
        console.dir(error);
      });

  });

})();