How to Set Reminders in Claude Desktop with MCP

Claude Desktop can set real, delivered reminders — not just remember something for the length of a conversation — if you connect it to an MCP server that handles scheduling. This guide walks through the setup in about two minutes, using the Model Context Protocol (MCP), the open standard Anthropic introduced for connecting Claude to external tools.

What you need

• Claude Desktop installed (macOS or Windows)
• Node.js installed, so `npx` is available on your machine
• A reminders.md account and an API key from Settings → API Access

Step 1: Open your Claude Desktop config

Claude Desktop reads its MCP server list from a JSON file. On macOS it lives at:

~/Library/Application Support/Claude/claude_desktop_config.json

On Windows, the equivalent path is %APPDATA%\Claude\claude_desktop_config.json. If the file doesn't exist yet, create it.

Step 2: Add the reminders server

Add an entry under mcpServers with your API key in the env block:

{
  "mcpServers": {
    "reminders": {
      "command": "npx",
      "args": ["-y", "reminders-md"],
      "env": {
        "REMINDERS_API_KEY": "your_key_here"
      }
    }
  }
}

The env block matters — without it, the server has no way to know which account to create reminders under. Grab your key from your dashboard under Settings → API Access before you start.

Step 3: Restart Claude Desktop

Fully quit and reopen the app (not just close the window). On startup, Claude Desktop launches each configured MCP server as a background process and negotiates which tools it exposes. You should see a small tools/plug icon in the composer once it connects.

Step 4: Try it

In a new conversation, just ask naturally:

"Remind me to check in with the team tomorrow at 9am."

Claude will call the create_reminder tool, parse the date, and confirm. You can also ask it to list what's coming up, snooze something, or mark a reminder done — all without leaving the conversation.

Troubleshooting

• Tool doesn't appear: confirm the JSON is valid (a trailing comma will silently break the whole file) and that you fully restarted the app.
• "Authentication required" errors: your REMINDERS_API_KEY is missing or was revoked — generate a new one from Settings.
• npx hangs on first run: it's downloading the package the first time; subsequent launches are instant.

Why this is better than a to-do list app

The point isn't that Claude Desktop needs its own reminders feature — it's that you're usually already in Claude when the thought "remind me about this" occurs, mid-conversation, mid-task. Setting the reminder without switching apps means it actually happens instead of getting lost when you tab away.