Minimal Google Calendar API event fetching JS

demo.js

const client_id = '...'
const client_secret = '...'

const authorizationCodeURL = `https://accounts.google.com/o/oauth2/v2/auth?${new URLSearchParams({
  scope: 'https://www.googleapis.com/auth/calendar',
  response_type: 'code',
  redirect_uri: 'urn:ietf:wg:oauth:2.0:oob',
  client_id,
})}`
const authorizationCode = prompt(`${authorizationCodeURL}\nauth code:`)!.trim()

const token = await fetch('https://www.googleapis.com/oauth2/v4/token', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    client_id,
    client_secret,
    code: authorizationCode,
    grant_type: 'authorization_code',
    redirect_uri: 'urn:ietf:wg:oauth:2.0:oob',
  }),
}).then(r => r.json())

const now = Temporal.Now.instant()
const eventResp = await fetch(`https://www.googleapis.com/calendar/v3/calendars/primary/events?${new URLSearchParams({
  timeMin: now.toString(),
  timeMax: now.add({ hours: 24 }).toString(),
  singleEvents: 'true', // expand reoccurring events into seperate instances
  orderBy: 'startTime',
})}`, {
  headers: { Authorization: `Bearer ${token.access_token}` },
}).then(r => r.json())

const events = eventResp.items
  .filter(event => event.status === 'confirmed') // no canceled/tenative
  .filter(event => event.start?.dateTime !== undefined) // no all-day events
console.log(events)