EK Bridge

EK Bridge Give AI agents your calendar. Not all of it.

A free, open-source Mac menu bar app that lets Claude, ChatGPT, Cursor and your scripts use only the calendars and reminder lists you choose, and asks you before they change anything.

Download for Mac · Get started · Agent setups · Changelog

• Choose what each agent can touch. Pick the calendars and reminder lists each agent may use, and whether it may read, create, edit, delete or complete. A new agent starts with nothing.
• Approve every change. A panel shows exactly what an agent wants to write. Nothing changes until you click Allow.
• See everything, switch it off in one click. Activity names what each agent changed and explains every refusal. Pause or remove an agent, or pause all of EK Bridge from the menu bar.

Works with Claude Code, Claude Desktop, Codex and Cursor (tested live), and any other MCP client, with ready-made setups for VS Code (Copilot), Gemini CLI, Zed, Cline, JetBrains AI Assistant and Devin Desktop. claude.ai and ChatGPT can connect through Remote Access, which is experimental.

What you can ask

Once an agent is connected, ask in plain words. It can act only inside the calendars and lists you gave it.

Twelve tools cover events and reminders, with every field Calendar supports: time zones, repeats, alerts, locations, notes and links. Each agent sees only the tools its access allows. The MCP guide has the full reference.

Get started

1. Install. Download EKBridge.dmg, open it and drag EK Bridge to Applications. If you open it from the disk image or Downloads instead, it offers to move itself there. Or use Homebrew:

   brew install --cask bereciartua/tap/ek-bridge

1. Open the app. It opens on a setup with three steps; later, you'll find it in the menu bar.
2. Allow access to Calendar and Reminders. You need only the one your agent uses; skip the other.
3. Add your agent. Pick its tile (agents found on your Mac come first) and what it can read to start with, such as Read all calendars and lists. Grant Read only where the agent needs it: what it reads goes to its AI provider.
4. Connect it. Add to Claude Desktop… (or Cursor, or Claude Code) shows the exact change to the agent's settings, keeps a backup and never writes the token; it also turns EK Bridge on. For other agents, copy the command or config from the connection's Connect tab. The step is done when the agent's first request arrives.

That's it: ask your agent one of the questions above. Setups for every agent and troubleshooting are in the MCP guide.

EK Bridge needs macOS 14 or later, on Apple silicon or Intel. It's notarized by Apple and keeps itself up to date (you click to install each update). Release notes and checksums are on Releases. Upgrading from EventKit Bridge, its earlier name? See Setup. EK Bridge is a personal project in public preview, with best-effort support.

How you stay in control

EK Bridge is the only app that holds your Calendar and Reminders permission. Your agents talk to it, never to your calendars directly, and it checks every request against what you allowed.

Each agent gets only what you tick

Every agent has its own key and its own access: Read, Create, Edit and Delete for each calendar, plus Complete for each reminder list. Share Work, keep Family to yourself.

You approve each change

By default, before an agent writes anything, a small panel shows every field it wants to set. Click Allow or Deny, or let one agent work for 15 minutes. A request you don't answer is refused after 45 seconds. For a script you trust, you can turn asking off.

It asks before it refuses

When an agent tries to add, change, complete or delete on a calendar it can read but lacks that one action, EK Bridge asks you in the same panel: *Claude Code can't add reminders to Groceries*. Allow Once, Always Allow (which saves just that action) or Not Now. It never asks about calendars the agent can't see, and at most once an hour for the same thing.

You can see everything, and stop anything

Activity says what each agent changed, by name (*Moved “Design review”*), and explains every refusal in plain words. EK Bridge stores only the item's ID and looks the name up when you open the row, with Show in Calendar. Pause an agent's connection to refuse its requests while keeping its setup, Remove it to cut it off for good, or pause all of EK Bridge from the menu bar. Optional notifications tell you when a change wasn't made because nobody answered.

Under the hood

• Local by default. Everything is off until you turn it on. The MCP server listens only on 127.0.0.1. No account, no analytics, no server of ours.
• A key per agent. Each agent has its own 256-bit token, stored only as a hash; scripts sign their requests with their own Ed25519 key.
• Safe writes. Edits and deletes need the latest version of an item. Every written field is read back, and a mismatch is rolled back.
• Cloud only through your tunnel. A cloud agent can reach EK Bridge only through Remote Access and a tunnel you run, for agents you allowed, and never while your Mac is asleep, offline or logged out.
• Signed updates. Updates come from GitHub, signed by the developer and checked before they install.
• Open source. Read the code, the threat model and the test record.

What it doesn't protect against: another program running as your macOS user can read the same key files. Access settings separate the agents you connect; they aren't a defense against malware already on your Mac. Details are in Security boundary.

FAQ

Is it free?

Yes. EK Bridge is open source under the Apache License 2.0, with no account or trial.

Does my calendar data leave my Mac?

EK Bridge itself sends nothing anywhere; Privacy lists every connection it makes. What an agent reads through it goes to that agent and its AI provider, under their terms, so grant Read only where the agent needs it.

Does it always ask before a change?

For AI agents, yes by default. You can turn asking off per connection, for example for a script you trust, or allow one agent's changes for 15 minutes at a time. See Ask before changes.

Which calendars work?

The accounts that appear in the Calendar and Reminders apps, such as iCloud, Google, Exchange, CalDAV and On My Mac. The live tests so far ran on iCloud; see Testing.

Can I use it with ChatGPT or claude.ai?

Yes, through Remote Access, which forwards cloud agents to your Mac through a tunnel you run, such as Tailscale Funnel. It's off by default and experimental, and your Mac has to be awake and online. See [From cloud agen