SwarmMarshal uses Google's official APIs to read your mail and calendar. Because Google restricts which apps can request those permissions, the cleanest path today is to create a small Google Cloud project of your own and paste the credentials into SwarmMarshal. It takes about ten minutes and only needs to be done once per Google account.
Google requires a paid annual security audit before an app can ship Gmail or Calendar access to the general public. SwarmMarshal is a local desktop app with no central server, so instead of gating the feature behind that process we let you create a personal Google Cloud project. Your OAuth tokens never leave your computer, Google only ever sees your own project talking to your own mailbox, and SwarmMarshal has no involvement in the transfer.
Sign in at console.cloud.google.com with the Google account you want to connect. In the project picker at the top, click New Project, name it something you'll recognize (for example SwarmMarshal Personal), and click Create. When the notification bell tells you it's ready, switch the project picker to the new project.
Open APIs & Services → Library, search for Gmail API, and click Enable. Repeat the search for Google Calendar API and enable that one too. These are the two APIs SwarmMarshal talks to — you don't need anything else.
Go to Google Auth Platform → Overview. If the page says Google Auth Platform not configured yet, click Get started. Fill in an app name (SwarmMarshal Personal is fine), choose your email as the user support email, choose External for the audience, then enter your email again as the developer contact. Accept Google's policy checkbox if shown, and finish the wizard. Test users live on a different page; we'll add you there next.
Open Google Auth Platform → Audience. Scroll to Test users and click + Add users. Paste the Gmail address you'll sign in with and Save. Without this step Google blocks sign-in with the message "Access blocked: this app has not completed the Google verification process".
Open APIs & Services → Credentials, click Create Credentials, and choose OAuth client ID. For Application type pick Desktop app and give it any name. Google will show you a Client ID and Client secret — keep that dialog open, you'll paste both into SwarmMarshal in the next step.
In SwarmMarshal open Settings → Accounts & Channels → Google. Paste the Client ID and Client secret from the Google Cloud dialog, then click Connect Google account. Your browser will open Google's sign-in page — because your project is in testing mode you'll see a "Google hasn't verified this app" warning. Click Advanced then Go to SwarmMarshal (unsafe), approve the requested permissions, and you'll be returned to SwarmMarshal with the account linked.
SwarmMarshal will pull your inbox and calendar on the normal sync schedule. You can revoke access at any time from your Google account permissions page or by deleting the OAuth client from your Cloud project. Removing the credentials from SwarmMarshal's settings screen also clears every token stored on this machine.
The warning screen has no "Advanced" link. Your consent screen is set to Internal — switch it to External in Step 3, or make sure you're signed in with the same Google account you added as a test user.
"Access blocked: SwarmMarshal has not completed the Google verification process". Add your Google address to the Test users list on the OAuth consent screen. Test users can use the app indefinitely without verification.
The connection works but nothing syncs. Double-check that both the Gmail API and the Google Calendar API are enabled under your project (Step 2). Enabling them is per-project, not per-account.
The Client ID and Client secret identify your project to Google. They're not a password to your mailbox — on their own they can't read any of your data. SwarmMarshal still encrypts them at rest along with the refresh token Google issues after sign-in.
Because the project is yours, only Google accounts you explicitly add as test users can sign in to it. If you want to share one installation with a family member, add their Google address as a test user and they can connect their own account the same way.