Connect Google Calendar
Once connected, every booking writes a pickup and a return appointment into a Google Calendar you choose, and reschedules, extensions and cancellations keep those appointments up to date.
The calendar link is entirely yours. You create the connection in your own Google Cloud account, HiLucy never sees your Google password, and no other operator on the platform can see your calendar or your credentials. That is also why setup takes about ten minutes the first time: you are creating the app that asks for permission, not just granting it.
You only do this once.
Before you start
You need a Google account -- the one that owns the calendar you want bookings to appear in. A free personal Gmail account works. So does Google Workspace.
Keep two browser tabs open:
- Tab A -- HiLucy: Rental Manager -> Settings -> Google Calendar
- Tab B -- Google Cloud Console
Everything below happens in Tab B until the last step.
1. Create a project
In Google Cloud, open the project picker at the top of the page and choose New project.
Name it something you will recognise later -- your business name is fine. Leave Location as it is. Click Create, then make sure the new project is selected in the picker before continuing. This is the single most common mistake: doing the rest of the setup inside a different project.
2. Turn on the Calendar API
Go to APIs & Services -> Library, search for Google Calendar API, open it and click Enable.
Without this, everything else will appear to work and the connection will fail at the last step with a permissions error.
3. Set up the consent screen
Go to APIs & Services -> OAuth consent screen. In newer versions of the console this is Google Auth Platform -> Branding.
Choose External as the user type. Then fill in:
| Field | What to put |
|---|---|
| App name | Your business name -- this is what you will see when you grant access |
| User support email | Your own email |
| Developer contact information | Your own email again |
You can leave the logo, the app domain and the authorised domains empty. Save and continue through the remaining pages; you do not need to add scopes here.
4. Publish the app
Still in the consent screen area, find Publishing status (in newer consoles: Google Auth Platform -> Audience). It will say Testing. Click Publish app and confirm.
Do not skip this. An app left in Testing has its access silently revoked by Google every 7 days. Your calendar would sync for a week, stop, and show "Reconnect needed" in HiLucy -- over and over. Publishing removes that expiry.
Publishing does not submit anything for review and does not cost anything. Google may offer to "prepare for verification" -- you can ignore that. See What "unverified" means below.
5. Create the credentials
Go to APIs & Services -> Credentials, click Create credentials -> OAuth client ID.
- Application type: Web application
- Name: anything -- "HiLucy" is fine
- Under Authorised redirect URIs, click Add URI
Now switch to Tab A. The HiLucy setup form shows a redirect URI in a grey box. Copy it exactly -- the whole thing, including https:// and everything after the last slash -- and paste it into Google.
A single wrong character here produces a redirect_uri_mismatch error at the end and nothing else will hint at why.
Click Create. Google shows your Client ID and Client secret. Leave this dialog open.
6. Paste them into HiLucy
Back in Tab A, paste the Client ID and Client secret into the two fields and click Save credentials.
If you close Google's dialog before copying the secret, you cannot see it again -- create a second OAuth client and use that one instead.
7. Connect
Click Connect Google account. A Google sign-in window opens. Sign in with the account that owns your calendar.
Google will warn you that the app is not verified. This is expected -- see below. Click Advanced, then Go to ... (unsafe), then Continue to grant access.
You will land back in HiLucy. Pick which calendar bookings should go to, click Save calendar, and you are done. Use Sync all bookings now to push your existing upcoming bookings across.
What "unverified" means
Google shows "Google hasn't verified this app" on any Google Cloud project that has not been through its formal review process. It is not a sign that anything is wrong, and it does not mean the app is unsafe.
The app is yours. You created it, in your own Google account, minutes ago. The name on that screen is the one you typed in step 3. You are being asked whether you trust an app you built to see your own calendar.
Verification exists for apps that ask thousands of strangers for access. It requires a privacy policy, a verified domain and a demo video, and takes weeks. For one business connecting one calendar it buys nothing, and Google's unverified limit -- 100 accounts -- is far beyond what you need.
If Google blocks you instead of warning you, that is a different problem: the app is still in Testing and the account you signed in with is not on its test-user list. Go back and complete step 4.
Troubleshooting
| What you see | What it means |
|---|---|
redirect_uri_mismatch | The URI in step 5 does not exactly match the one HiLucy shows. Re-copy it; check for a missing or extra trailing slash. |
| "Access blocked: ... has not completed the Google verification process" | The app is still in Testing. Publish it (step 4). |
| "Enter your Client ID and Client Secret first" | The credentials did not save. Re-enter them; the secret is never displayed back to you, so a blank-looking field is normal. |
| Sync worked, then stopped after about a week | Classic Testing-mode symptom. Publish the app, then disconnect and reconnect. |
| Calendar API has not been used in project ... | Step 2 was skipped, or done in a different project. |
| "Reconnect needed" in HiLucy | Google revoked the token -- password change, long inactivity, or access removed from your Google account. Disconnect and connect again. |
Changing or moving the connection
The Change link next to your Client ID in Settings reopens the credentials form, so you can point HiLucy at a different Google Cloud project without losing anything else.
To stop syncing entirely, click Disconnect. That removes HiLucy's access token. Appointments already written to your calendar stay where they are -- delete them in Google Calendar if you want them gone.
You can also revoke access from Google's side at any time, under your Google account's third-party access settings.