nodeを使ってGoogle Calenadar APIを使う（サービスアカウントを使用）

{
  "type": "service_account",
  "project_id": "",
  "private_key_id": "",
  "private_key": "",
  "client_email": "",
  "client_id": "",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": ""
}

$ mkdir google-calendar-sample
$ cd google-calendar-sample

# ライブラリのインストールを行うためpackage.jsonを作成
$ yarn init -y
 
# Google Calendar APIを利用するためのライブラリを追加
$ yarn add googleapis

.
├── index.js
├── package.json
├── service-account-key.json
└── yarn.lock

const { google } = require('googleapis')
 
const SCOPES = 'https://www.googleapis.com/auth/calendar.readonly'
const GOOGLE_PRIVATE_KEY = require('./service-account-key.json').private_key
const GOOGLE_CLIENT_EMAIL = require('./service-account-key.json').client_email
const GOOGLE_PROJECT_NUMBER = '<GCPのページよりプロジェクト番号を調べて記載>'
const GOOGLE_CALENDAR_ID = '<GoogleカレンダーのページよりカレンダーIDを調べて記載>'
 
const jwtClient = new google.auth.JWT(GOOGLE_CLIENT_EMAIL, null, GOOGLE_PRIVATE_KEY, SCOPES)
 
const calendar = google.calendar({
  version: 'v3',
  project: GOOGLE_PROJECT_NUMBER,
  auth: jwtClient,
})
 
const main = () => {
  // 現在以降の最新10件のイベントを取得
  calendar.events.list(
    {
      calendarId: GOOGLE_CALENDAR_ID,
      timeMin: new Date().toISOString(),
      maxResults: 10,
      singleEvents: true,
      orderBy: 'startTime',
    },
    (error, result) => {
      if (error) {
        console.log(error)
      } else {
        if (result.data.items.length) {
          console.log(result.data.items.map((item) => console.log(item)))
        } else {
          console.log('No upcoming events found.')
        }
      }
    }
  )
}
 
main()

const GOOGLE_PROJECT_NUMBER = '<GCPのページよりプロジェクト番号を調べて記載>'

const GOOGLE_CALENDAR_ID = '<GoogleカレンダーのページよりカレンダーIDを調べて記載>'

node index.js

{
  kind: 'calendar#event',
  etag: '"***"',
  id: '***',
  status: 'confirmed',
  htmlLink: 'https://www.google.com/calendar/event?eid=***',
  created: '2023-01-02T23:00:51.000Z',
  updated: '2023-01-02T23:00:51.288Z',
  summary: 'sample',
  creator: { email: '***@gmail.com', self: true },
  organizer: { email: '***@gmail.com', self: true },
  start: { date: '2023-01-03' },
  end: { date: '2023-01-04' },
  transparency: 'transparent',
  iCalUID: '***@google.com',
  sequence: 0,
  reminders: { useDefault: false },
  eventType: 'default'
}
{
  kind: 'calendar#event',
  etag: '"***"',
  id: '***',
  status: 'confirmed',
  htmlLink: 'https://www.google.com/calendar/event?eid=***',
  created: '2023-01-02T23:01:00.000Z',
  updated: '2023-01-02T23:01:00.685Z',
  summary: 'sample 2',
  creator: { email: '***@gmail.com', self: true },
  organizer: { email: '***@gmail.com', self: true },
  start: { dateTime: '2023-01-04T08:00:00+09:00', timeZone: 'Asia/Tokyo' },
  end: { dateTime: '2023-01-04T09:00:00+09:00', timeZone: 'Asia/Tokyo' },
  iCalUID: '***@google.com',
  sequence: 0,
  reminders: { useDefault: true },
  eventType: 'default'
}