# Cider > Apple MCP Server — Calendar, Reminders, Notes, Contacts, Mail via AppleScript - **Type:** MCP server - **Install:** `agentstack add mcp-proxynico-cider` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [proxynico](https://agentstack.voostack.com/s/proxynico) - **Installs:** 0 - **Category:** [Productivity](https://agentstack.voostack.com/c/productivity) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [proxynico](https://github.com/proxynico) - **Source:** https://github.com/proxynico/cider ## Install ```sh agentstack add mcp-proxynico-cider ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Cider Local Apple Calendar, Notes, and Contacts tools for Claude Code, Codex, and other AI assistants on macOS. Cider lets an AI assistant use the Apple apps already on your Mac. It connects Claude Code, Codex, or another MCP client to: - Apple Calendar - Apple Notes - Apple Contacts - a `doctor` check that tells you whether the setup is healthy You install it once, register one MCP server, approve the normal macOS privacy prompts, and then your assistant can help with calendar events, notes, and contacts from your local machine. MCP is the tool/plugin connection used by assistants like Claude Code and Codex. In practice, Cider is the bridge between your assistant and your Apple apps. ## What It Can Do Calendar: - list your calendars - search events by date range - create events - update events - delete events - use event IDs so common titles like "Lunch" or "Call" do not hit the wrong event Notes: - list folders and notes - read and search notes - create, append, move, update, and delete notes Contacts: - list and search contacts - read contact details - create, update, and delete contacts Diagnostics: - run `doctor` to confirm Bun, AppleScript, the Calendar helper, Calendar access, Notes access, and Contacts access are working. ## Install ```bash git clone https://github.com/proxynico/cider.git cd cider bun install bun run build:swift ``` `bun run build:swift` creates the small signed **Cider Calendar Helper** app that macOS uses for Calendar permission. ## Register With Claude Code ```bash claude mcp add --scope user cider -- bun run /path/to/cider/src/index.ts claude mcp get cider ``` Example for this local checkout: ```bash claude mcp add --scope user cider -- bun run /Users/nicolasmontero/Developer/tools/cider/src/index.ts ``` Restart Claude Code after registering or updating Cider. ## Register With Codex ```bash codex mcp add cider -- bun run /path/to/cider/src/index.ts codex mcp list ``` Example for this local checkout: ```bash codex mcp add cider -- bun run /Users/nicolasmontero/Developer/tools/cider/src/index.ts ``` Restart Codex after registering or updating Cider. ## Approve macOS Permissions macOS controls access to Calendar, Notes, and Contacts. Cider cannot bypass those prompts, and that is a good thing. After registration, ask your assistant to run: ```text doctor ``` Then try a harmless Calendar read: ```text calendar_list_calendars ``` If macOS asks for Calendar access, approve it. If no prompt appears, open: ```text System Settings > Privacy & Security > Calendars ``` Make sure **CiderCalendarHelper** is enabled with **Full Access**. For Notes and Contacts, use: ```text System Settings > Privacy & Security > Automation ``` Allow your MCP client or terminal app to control Notes and Contacts if macOS asks. ## Check That It Works From your assistant, run: ```text doctor ``` A healthy setup looks like this: ```text OK bun OK osascript OK Notes automation OK Contacts automation OK calendar helper calendar authorization: authorized OK calendar permission: granted ``` Then try: ```text calendar_list_calendars notes_list_folders contacts_list ``` If those work, Cider is ready. ## Using Calendar Safely Calendar search returns an `eventId`. Use that `eventId` when updating or deleting events. That is safer than updating by title alone, because many calendars have repeated titles like "Meeting", "Lunch", or "Call". Example flow: 1. Search for events in a date range. 2. Pick the right event from the results. 3. Use its `eventId` to update or delete it. Mutating Calendar, Notes, and Contacts tools also support `dryRun: true` where available, so your assistant can preview the action before changing anything. ## Dates Use ISO-style dates: ```text 2026-05-12 2026-05-12T10:30:00 2026-05-12T10:30:00Z 2026-05-12T10:30:00+02:00 ``` Date-only values mean local midnight on your Mac. ## Troubleshooting Run `doctor` first. It is the fastest way to see what is broken. If Calendar says `notDetermined` or denied: - run `calendar_list_calendars` - approve the prompt if it appears - check that **CiderCalendarHelper** is enabled in Calendar privacy settings - restart the MCP client after changing permissions If Notes or Contacts fail: - check Automation permissions for the app running Cider - restart the MCP client after changing permissions If tools disappeared or still use old behavior: - quit old Claude/Codex sessions - start a fresh session so the MCP server reloads the latest code ## Development Useful commands: ```bash bun install bun run build:swift bun run test bun run src/index.ts ``` Before shipping changes, run: ```bash bun run build:swift bun run test git diff --check ``` For a full live smoke test, also verify: - `doctor` - `calendar_list_calendars` - a temporary Calendar create/update/delete - temporary Notes and Contacts create/read/delete if those surfaces changed ## How It Works Cider is one local MCP server. The TypeScript server exposes the tools. Calendar uses a small signed helper app because macOS grants Calendar permission to apps, not anonymous background scripts. Notes and Contacts use Apple automation. No cloud account, API key, or external database is required. Access stays on your Mac and is controlled by macOS privacy settings. ## License MIT ## Source & license This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [proxynico](https://github.com/proxynico) - **Source:** [proxynico/cider](https://github.com/proxynico/cider) - **License:** MIT Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/mcp-proxynico-cider - Seller: https://agentstack.voostack.com/s/proxynico - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.