MOMSync's MCP server, momsync-mcp, connects Claude Desktop to the Outlook data already on your Mac.
It only ever reads a private copy of that data, it never changes Outlook, and nothing leaves your Mac except the answers it gives Claude.
| You need | Notes |
|---|---|
| A Mac on macOS 14 or later | |
| Classic Outlook for Mac, with your accounts added | New Outlook for Mac isn't supported yet. |
| The MOMSync app, running | Needed for the sync tools. The calendar, mail and contacts tools work without it. |
momsync-mcp, MOMSync's MCP server | A separate program. It isn't included in the App Store version of MOMSync. |
| Claude Desktop | Or any other app that can use MCP servers. |
| Administrator access to System Settings | To grant Full Disk Access. |
momsync-mcp somewhere permanentMake a bin folder in your home folder and copy the program into it, so its path is ~/bin/momsync-mcp. In Terminal:
mkdir -p ~/bin
cp ~/Downloads/momsync-mcp ~/bin/
chmod 755 ~/bin/momsync-mcp
In Claude Desktop choose Settings → Developer → Edit Config, which opens
~/Library/Application Support/Claude/claude_desktop_config.json. Add a momsync entry under
mcpServers, keep anything already in the file, and use your own home folder in the path:
{
"mcpServers": {
"momsync": { "command": "/Users/yourname/bin/momsync-mcp" }
}
}
momsync-mcp Full Disk AccessOpen System Settings → Privacy & Security → Full Disk Access, click +, press
Cmd-Shift-G, enter ~/bin/momsync-mcp and choose Open. Make sure its switch is on.
Add Terminal the same way if you'll run the commands below.
macOS treats Outlook's data as another app's private data. Claude Desktop starts momsync-mcp as a separate
process, so it needs its own access: giving Claude access isn't enough.
Full Disk Access only takes effect when an app restarts, and Claude only loads new MCP servers when it starts. After reopening, momsync appears in Claude's list of connectors.
In Terminal:
~/bin/momsync-mcp doctor
~/bin/momsync-mcp index
doctor should show a tick on every line. The first index reads your whole Outlook store and takes one to two
minutes for a large mailbox; after that, refreshes take a few seconds. If you skip it, Claude's first request does it instead and takes that long to answer.
Calendars and contacts start switched on for every account; mail and attachments start switched off. Each account has its own switches, and an account that's switched off is invisible to Claude.
| To do this | Run |
|---|---|
| See current settings and every account | ~/bin/momsync-mcp config |
| Allow mail for one account | ~/bin/momsync-mcp config set you@company.com mail on |
| Allow mail for every account | ~/bin/momsync-mcp config set all mail on |
| Hide one account's calendar | ~/bin/momsync-mcp config set you@client.com calendar off |
| Include the local "On My Computer" store | Use local as the account name |
| Allow attachment downloads (up to 10 MB) | ~/bin/momsync-mcp config attachments on |
| Set working hours for free-time searches | ~/bin/momsync-mcp config hours 08:30-18:00 1,2,3,4,5 (1 = Monday) |
| Set the time zone | ~/bin/momsync-mcp config timezone Europe/London |
| Treat a calendar as yours, shared, a room or holidays | ~/bin/momsync-mcp config calendar <id> own (ids from list_calendars) |
Changes apply to Claude's next request, with no restart needed. Accounts you add to Outlook later appear automatically, with mail off.
Ask Claude in plain English. Good first requests:
To show your busy time on a client's calendar without revealing other clients' meetings, add a busy-block route in the MOMSync app: Sync Routes → Add Busy Blocks.
| Command | What it does |
|---|---|
momsync-mcp | Runs the MCP server. Claude Desktop starts it this way; you don't run it yourself. |
momsync-mcp doctor | Checks Outlook access, the data format, the index and the link to the MOMSync app, and says how to fix anything missing. |
momsync-mcp index | Builds or refreshes the index now. Add --force to re-read everything. |
momsync-mcp config | Shows settings, accounts and file locations. momsync-mcp config help lists every option. |
momsync-mcp config profile <folder> | Uses an Outlook profile other than "Main Profile". default switches back. |
momsync-mcp tools | Lists the 20 tools Claude can use. |
momsync-mcp call <tool> '<json>' | Runs one tool and prints the result, e.g. momsync-mcp call next_meeting '{}'. |
momsync-mcp --version | Shows the version. |
Start with ~/bin/momsync-mcp doctor: every ✗ line says what to do.
| Problem | Fix |
|---|---|
| "Can't read … Outlook.sqlite" | Give Full Disk Access to momsync-mcp itself (for Claude) and to Terminal (for commands you run there), then quit and reopen Claude or Terminal. Granting it to Claude alone isn't enough. |
| "No Outlook database at …" | Your profile isn't called "Main Profile". Run momsync-mcp config profile "<path to your profile folder>". |
| "schema version … hasn't been tested" | An Outlook update changed its data format. Update momsync-mcp; to try anyway, run with MOMSYNC_ALLOW_UNKNOWN_SCHEMA=1. |
Results flagged stale | Classic Outlook has stopped updating its data, usually because you switched to New Outlook. Switch back to keep MOMSync current. |
| "Mail access is switched off" | Run momsync-mcp config set <account> mail on. |
| "The MOMSync app isn't running" | Open MOMSync. The sync tools need it running; everything else works without it. |
| "momsync" missing from Claude | Check the path in claude_desktop_config.json matches where you put the program, then quit and reopen Claude. |
| First request is slow | It's building the index. Run momsync-mcp index once to do this up front. |
| A sync preview shows deletions "held" | More than 20 events (or more than 10% of a route's events) would be deleted, so MOMSync is waiting for you. Check them, then press Allow on next sync on the route in the MOMSync app. |
Everything stays on your Mac. momsync-mcp sends nothing anywhere except the answers it gives the app that started it.
Each refresh copies Outlook's database into a private folder, reads the copy and deletes it; Outlook's own files are never opened or changed.
| File | Location (readable only by you) |
|---|---|
| Settings | ~/Library/Application Support/MomSync/mcp-config.json |
| Index | ~/Library/Application Support/MomSync/index.sqlite |
| Activity log (each request, kept 30 days, email searches redacted) | ~/Library/Application Support/MomSync/audit.log |
Text from emails and invitations is marked as coming from other people, and instructions hidden in an email can't make MOMSync act.
To remove the facility, delete the momsync entry from Claude's config, delete ~/bin/momsync-mcp, and delete ~/Library/Application Support/MomSync.
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