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n8n is an open-source workflow automation platform that lets you connect hundreds of applications together without writing complicated code. Here's what's interesting: once you integrate Google Calendar into n8n, every change to your schedule—a new event, a cancellation, a time shift—can become the starting trigger for an automated workflow that handles everything downstream.

To make this work, n8n requires OAuth2 credentials that you create yourself on Google Cloud. The process sounds intimidating at first, but it really only takes 10-15 minutes if you follow the steps below carefully.

Connecting Google Calendar to n8n: Step-by-Step

Step 1: Add the Google Calendar Node to Your Workflow

Open n8n and create a new workflow. Click the Add first step button in the center of your screen. In the search bar that appears on the right, type calen to filter your options. You'll see suggestions including Calendly and Google Calendar—select Google Calendar.


Step 2: Choose Your Trigger or Action

After selecting Google Calendar, n8n displays all available features organized into two categories. The Triggers section contains 5 types of event-based activators: On event cancelled, On event created, On event ended, On event started, and On event updated. The Actions section includes 6 direct actions you can perform on your calendar. Pick the trigger that matches your workflow goal. For example, choose On event started if you want your workflow to run the moment an event begins.


Step 3: Open the Credential Settings

Your Google Calendar Trigger node appears with a configuration panel on the right. In the Credential field, you'll see "No credentials" with a red warning icon. Click the Set up credential button in the bottom right corner to begin authentication.

A Google Calendar account window opens, displaying your OAuth Redirect URL in the format http://localhost:5678/rest/oauth2-credential/callback. Copy this URL now—you'll need it in the next step. Click Click To Copy for a quick copy.


Step 4: Create a New Project on Google Cloud

Open your browser and navigate to console.cloud.google.com. Click your current project name in the top navigation bar to open the project selector. Click New project in the upper right corner.

On the new project creation page, enter a name in the Project name field—something like n8n-QTM-CLD works well. The Project ID generates automatically and cannot be changed afterward. Click Create to finish.


Step 5: Select Your New Project

Once your project is created, Google Cloud shows a success notification in the Notifications area (bottom right corner). Click Select Project in that notification to switch to your new project. The navigation bar title updates to reflect your new project name.


Step 6: Enable the Google Calendar API

In Google Cloud Console, go to APIs & Services and select Library. Alternatively, use the search bar next to your project name and search for Google Calendar API, then open its detail page. Click the Enable button to activate the API for your project. Once enabled, the page switches to the API management dashboard with tabs for Overview, Documentation, and Support.


Step 7: Configure the OAuth Consent Screen

Go to APIs & Services and select OAuth consent screen. You'll see a message saying "Google Auth Platform not configured yet." Click Get started to begin configuration.

The setup includes 4 short steps. In the App Information step, enter an app name in the App name field—for example, n8n-QTM-Calendar. Select a support email address in the User support email field. Click Next.

On the Audience step, keep the default setting as External since you're using a personal Google account. Click Next.

On the Contact Information step, enter an email address where Google can notify you of any project-related changes. Click Next.

On the Finish step, check the box to agree with Google API Services User Data Policy, then click Continue. Next, click Create OAuth client to complete the consent screen setup.


Step 8: Create Your OAuth Client ID

After your consent screen is ready, the OAuth Overview page displays a Metrics section indicating no OAuth client exists yet. Click Create OAuth client to begin.

On the Create OAuth client ID page, set Application type to Web application (item 1 in the screenshot). Enter a name in the Name field—for example, Web client 1 (item 2).

Scroll down to the Authorized redirect URIs section. Click Add URI and paste the callback URL you copied from n8n in Step 3—specifically, http://localhost:5678/rest/oauth2-credential/callback. Click Create.


Step 9: Copy Your Client ID and Client Secret

Google Cloud displays an "OAuth client created" dialog with complete details. Copy both your Client ID and Client Secret right now—after you close this dialog, you won't be able to view your Client Secret again. You can also download a JSON file for secure storage using the Download JSON button.


Step 10: Enter Your Credentials in n8n and Sign In

Return to n8n and paste your Client ID and Client Secret into the corresponding fields in the Google Calendar account window. Click Sign in with Google to complete the connection.

Troubleshooting the "Access blocked" Error

If you encounter an error message saying "Access blocked: [app name] has not completed the Google verification process" with code Error 403: access_denied, you've hit a common issue. This happens when your app is in Testing mode and you haven't added your account to the test user list.

Here's how to fix it: Return to Google Cloud Console and go to APIs & Services → OAuth consent screen. Select the Audience tab from the left menu (item 1 in image 20). Click Add users (item 2), enter your Gmail address in the email field (item 3), then click Save (item 4). Go back to n8n and try signing in with Google again.

Check the boxes to grant n8n access to your Google Calendar and click Continue.


What Can You Do With Google Calendar Connected to n8n?

Once the connection is established, Google Calendar becomes part of your n8n automation ecosystem. Here's what becomes possible.

Automate Workflows Based on Calendar Events

  • The five Google Calendar trigger types in n8n let you build workflows that activate automatically whenever your schedule changes. When a new event is created, n8n can automatically send confirmation emails to attendees via Gmail, create matching tasks in Notion or Trello, or post alerts to your Slack channel. When an event starts, n8n can send SMS reminders, open related documents, or launch a meeting bot. When an event ends, n8n can automatically save summary notes, update project statuses, or send feedback surveys to participants.

Manage and Sync Calendar Data Across Systems

  • Using the Actions group, n8n can actively read, create, update, or delete calendar events based on data from other applications. For instance, when a new order arrives from WooCommerce, n8n automatically creates a shipping event on your calendar. When a customer books through a Typeform form, n8n instantly creates the corresponding appointment and sends Google Meet links to both parties. Everything runs hands-free on your end.

Important Considerations Before Going Live

  • If you're running n8n on localhost instead of a real domain, Google OAuth won't permit authentication in production. For actual work, you'll need to deploy n8n on a server with a valid HTTPS address and update the Authorized redirect URI in Google Cloud accordingly. The real concern is that apps in Testing mode only support up to 100 test users, and tokens expire after 7 days. If you want stable long-term usage, plan to submit your app for Google verification.


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