Remote Frog

What if your AI agent had a working memory? A log where you describe the steps you take, your findings, notes, and outputs… and you could bring them into context whenever you need them. That’s exactly what I can do by connecting Day One to Cursor through its MCP server.

Note: The Day One MCP server is currently available only for Day One for Mac.

What is MCP?

MCP (Model Context Protocol) is an open standard that allows AI models to connect with external data sources in a structured way. Think of it as a bridge between your AI agent and any service or application that has an MCP server available.

Why Day One as Working Memory?

Day One is a journaling app that I use to log thoughts, decisions, learnings, and daily reflections. By connecting it as a context source for Cursor, we get something really powerful:

• Persistent personal context: Your agent can access previous notes, decisions, and reflections.
• Clean up some .md files. Sometimes my agent in Cursor writes notes in Markdown files. Usually, it does so in folders listed in .gitignore, but it’s happened more than once that things got out of hand and suddenly the notes show up in a PR! I also prefer keeping the codebase working folder clean of notes.
• Long-term memory you can add to the agent’s context on demand: Unlike the memory of a conversation (ephemeral and expensive at each call!), your journal persists and it is used when needed. It becomes referenceable, shareable, linkable, and searchable. And you can look up notes and add them to the agent’s context only when you need them — without overloading it.
• Natural workflow: You write in your journal as you always do, and the agent can leverage that information when needed.

Security and Privacy

• 100% local execution: The MCP server makes no network calls. It accesses Day One’s local database directly. That said, while the server is local, the content it retrieves will be sent to the LLM for processing.
• Per-journal control: You decide which journals are accessible.
• Password lock protection: If Day One’s password lock is enabled, the MCP server won’t work.

Other Reasons Day One Is Great (Beyond AI Working Memory)

Day One is great. Really great. It was Apple’s App of the Year and won the Apple Design Award. But instead of reading reviews and other people’s opinions, I’d recommend downloading it from the Mac App Store and giving it a spin. Why? Off the top of my head:

• It’s a well-organized basic journaling app with Journals to separate your contexts (work, personal, a trip…). It has customizable templates for recurring entries, and entries support markdown, photos, videos, audio, and drawings.
• What makes it special vs regular notes: It’s designed to capture moments. It automatically captures context (GPS location, weather, music you were listening to, step count, date/time…). So each note is like a time capsule — and all that metadata can be used for searching, for thousands of AI applications, or to show you ‘where you wrote your entries on a map’ (this is awesome if you take notes while traveling).

• It nudges you to write with configurable reminders and features like “On This Day” (what you wrote on this date in previous years).
• Solid organization (tags and filters of course, powerful full-text search, interactive maps with geolocated entries, different views…)
• You can export entries or journals to PDF or JSON / plain text for other apps to format. You could even export to physical books, though I haven’t tried that one 😀
• Useful integrations: Siri, Share extension — send content from any app to Day One —, MCP server.

There are more ideas in this post where they show their Day One setup, where they also offer a course for $29.

Setup

Alright, alright. The setup!

First step is easy. If you don’t have it yet, install Day One from the Mac App Store.

Step 1: Install the Day One CLI

The MCP server is built into the Day One app, but you need to install the CLI (command-line interface) to invoke it. Run in your terminal:

sudo bash /Applications/Day\ One.app/Contents/Resources/install_cli.sh

This installs the dayone command to /usr/local/bin/dayone. You can verify the installation with:

/usr/local/bin/dayone --version

At this moment, version: 2026.5.1.1739

Step 2: Configure Cursor to Use the MCP Server

Edit (or create) the file ~/.cursor/mcp.json and add the Day One server configuration:

{
  "mcpServers": {
    "dayone-cli": {
      "command": "/usr/local/bin/dayone",
      "args": ["mcp"],
      "transport": "stdio"
    }
  }
}

Restart Cursor so it detects the new MCP server.

Step 3: Enable MCP Access in Day One

For security and privacy, Day One requires you to explicitly grant MCP access to your journals:

1. Open Day One, go to Settings → Labs, and enable Labs
2. Enable “Mac CLI MCP Server”
3. Click “MCP Access Control”
4. Toggle on the journals you want to make accessible

Only the journals you enable here will be visible to AI assistants. You have complete control over access.

What Can You Do Once Connected?

Once it’s set up, you can ask Cursor things like:

• “Search my journal for the notes I took about project X last week”
• “What decisions did I log about the service architecture?”
• “Summarize my journal entries from this week”
• “Create a journal entry with a summary of what we did today”
• “What did I write on this day in previous years?”

Practical Use Cases

Automated standup: The agent reviews your recent entries and generates a summary of what you’ve done and — depending on your entries — what you plan to do or what it suggests you tackle next.

Decision documentation: Log technical decisions in your journal and the agent can retrieve them when you’re working on related code. I also think an agent could tag entries on the fly, which makes them indexed and easier to find and use later.

Reflection and learning: The agent can connect what you’re doing now with previous reflections you wrote in your journal.

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Final Thoughts

Using a Day One journal as working memory for an AI agent is a good example of how a dead-simple MCP can make your life easier and your work more straightforward. Day One is not the only posibility, but you could also log your notes in Notion, Obsidian… lots of options!

It’s a simple integration to set up and can have a significant impact on your daily workflow. Give it a try and let me know how it goes.

Official repo: bloom/dayone-mcp-server (© Automattic, Inc.)