How to Connect Multiple Google Calendars to Claude Code
One Claude Code session can see every Google Calendar you own at the same time once Carly is holding them. Authorize each Google account in Carly, register one MCP server, and the terminal reads all of them together.
The ceiling you are hitting is not a Claude Code setting. Anthropic’s Google Workspace connector help page puts it plainly: Claude can only reach the Gmail, Calendar, and Drive data for the Google account you have connected. A personal Gmail, an employer’s Workspace, and a second client Workspace are three identities, and that connector holds one.
Connectors you added on claude.ai became usable inside Claude Code in a February 2026 release, listed under claudeai on the /plugin screen, on a paid Claude plan. Convenient, and it inherits the one-account ceiling exactly as it stands on claude.ai. Everything else Claude Code reaches outside your repository arrives over the Model Context Protocol, which makes the calendar count a property of the server you register rather than of Claude Code itself.
1. Add your Google calendars to Carly
- Sign in at carlyassistant.com.
- Open carlyassistant.com/integrations.
- Find Google Calendar, click Connect, and authorize the account.
- Click Connect again for the next one, and keep going for as many accounts as you want.
Choose Use another account if Google preselects the login you just finished, and confirm the full address before starting the next. If a Workspace requires administrator review, ask that administrator to approve the connection, then finish authorizing. Each Workspace approves independently, so a client tenant saying yes has no bearing on your employer’s.
Carly then calculates availability across every connected Google Calendar and Outlook calendar together, while each event stays on the calendar that owns it. Connected calendars and booking pages are unlimited, so a fourth account costs nothing extra.
Carly connects to thousands of apps, so while you are on that page you can add your inboxes, files, CRM, and anything else you want Claude Code to reach through the same connector.
2. Register Carly as an MCP server
Carly is a remote HTTP server, so one command does it:
claude mcp add --transport http --scope user carly https://carlyassistant.com/mcp/--scope user stores the server in ~/.claude.json and loads it in every project, which is what you want for calendars. Drop the flag and it lands in local scope, available only where you added it. Use --scope project to write it into a committed .mcp.json and share it with a team.
Then authenticate:
claude mcp login carlyThat opens a browser for the OAuth flow. Sign in to the Carly workspace holding the calendars. Anthropic’s Claude Code documentation covers the same flow from the /mcp panel inside a session, plus --no-browser for machines without one.
Confirm the server is live before moving on:
claude mcp listA healthy entry reads ✔ Connected. ! Needs authentication means the OAuth flow did not finish, ✘ Failed to connect points at the URL or the network rather than your Carly account, and ⏸ Pending approval appears on project-scoped servers awaiting acceptance.
What one session can do afterwards
- “Look at all my calendars and find three 45-minute slots this week that work for a call with Adobe.”
- “Find an hour before Friday that is free on all of my calendars and book the Databricks review on the client one.”
- “List everything I am double-booked for over the next two weeks, from all of my calendars.”
- “Send Emily Parker a booking link for a 30-minute intro that respects every calendar I have connected.”
Nothing is merged and nothing is forwarded. Each Google account keeps its own authorization, every calendar under it keeps its own name, and a write lands on the calendar that owns the event.
Why one server beats one per Google account
The usual alternative is a community Google Calendar MCP server. Each asks you to create a Google Cloud project, configure an OAuth client of the Desktop app type, and add your own address as a test user on the consent screen. The most widely used of them documents the sting in its own setup notes: while the app sits in testing mode its tokens expire after a week, so you re-authorize every Monday until you push the project to production. Now do that three times, for accounts two of which are governed by administrators who did not create your Cloud project.
The gap is well known. A feature request filed on the Claude Code GitHub repository in March 2026 asked for multiple Google accounts in the built-in Gmail and Calendar integrations, observing that there is no way to add a second Google account through Claude’s settings. It was closed as out of scope for that repository rather than answered with a setting.
Community calendar MCP servers versus Carly in Claude Code
| Need | Per-account Google Calendar MCP server | Carly MCP server |
|---|---|---|
| Read one calendar | Yes | Yes |
| Hold three Google identities | One server and one OAuth client each | One server, all accounts |
| Find a free hour across all of them at once | Stitched together by hand | Yes, in one question |
| Maintain your own Google Cloud project | Usually required | No |
| Outlook calendars in the same session | Separate server again | Same connector |
| Keep the work running with the terminal closed | No | Yes |
Carly gives Claude Code one calendar toolset that already spans your accounts instead of a stack of per-account servers. Carly offers free Zapier-style workflows; AI agents start at $35/month.
The part that outlives the session
A terminal session ends when you close it. Scheduling does not. The invite that lands while you are in a meeting, the client asking for times on a Sunday, the block that needs moving because a flight shifted: none of it waits for you to open a terminal.
That work belongs in a Carly workflow or a Carly agent, which runs in the cloud with nothing open. Carly watches each connected calendar individually, so a rule can fire on an invite landing in the client Workspace and stay quiet on the personal account. Booking pages run from the same place, checking every connected calendar before offering a slot.
One wrinkle if you want Carly inside a Claude Code routine: routines run in the cloud against the connectors on your claude.ai account, and a server added locally with claude mcp add lives on your machine. Add Carly at claude.ai/customize/connectors too, or declare it in a committed .mcp.json so it arrives with the cloned repository. Routines also start from a schedule, a pull request, or an HTTP call, and each needs a repository, so none of them notices a meeting request.
Quick fixes when a calendar does not appear
| Problem | Fix |
|---|---|
Server shows ! Needs authentication | Run claude mcp login carly and finish the browser flow |
| Server missing in another project | Re-add with --scope user, or move the entry out of local scope |
claude -p reports the tools are unavailable | Sign in interactively once with /mcp, then rerun the script |
| Google connected the same account twice | Remove the duplicate and reconnect with Use another account |
| A calendar inside a connected account is missing | Confirm it is visible in Google Calendar for that login, then reconnect |
| An event landed on the wrong calendar | Ask for the source calendar alongside each event and confirm before writes |
Frequently asked questions
Does Claude Code have a built-in Google Calendar connector?
Indirectly. Connectors you set up on claude.ai, Google Calendar included, are available inside Claude Code on a paid plan. Anthropic lists that connector on Pro, Max, Team, and Enterprise. It authorizes a single Google account, which is the whole problem this guide solves.
How many Google Calendars can one Claude Code session reach?
As many as you authorize in Carly. Claude Code registers one server, so the count is a Carly setting rather than a Claude Code one, and a single question reads across all of them.
Can Claude Code compare my work and personal calendars in one question?
Yes, once both accounts are connected in Carly. Ask for a free hour across all of your calendars and Carly evaluates them together, including Outlook calendars if you connected those too.
Will this work in a non-interactive run?
Yes, after you have signed in. Anthropic’s Claude Code documentation notes that cloud and non-interactive sessions cannot display the OAuth panel, so complete claude mcp login carly from an interactive session first and the run inherits the stored credentials.
Related: Multiple Gmail accounts in Claude Code · Claude Code MCP · Multiple accounts in Claude Code · Multiple Google Calendars in Claude · Best AI assistants for multiple Google Calendars · Carly’s Google Calendar integration
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