TandemLoop is a native app for Mac, iPad, and iPhone that helps you keep your tasks and projects organized—no database required, no cloud dependency, right on your device.
Your Data—Your Data Folder
Everything you capture in TandemLoop lives as plain Markdown files with YAML frontmatter in a folder on your device—your data folder. You choose where it’s stored—on your device or in iCloud Drive. You can open it in the Finder at any time, read it with a text editor, and use it in other tools.
No lock-in, no proprietary format. The data folder is readable—for you, for other apps, and for AI agents.
Everything local—sync optional. TandemLoop itself sends nothing over the network and has no built-in cloud connection. If you want to use your data folder on several devices, put it in iCloud Drive—iCloud then takes care of syncing across devices. For more, see The Data Folder & File Format.
GTD Spirit: Capture First, Then Process
TandemLoop follows the idea of saving thoughts quickly before you worry about where they belong. The Inbox is where everything lands first—in seconds, through Quick Entry, without interrupting your current work. Afterward, you calmly decide whether something belongs in an area, a project, or straight in the Trash.
You organize your work in areas (the big areas of your life), projects, and tasks. You’ll learn the exact structure in Understanding the Hierarchy.
The AI Tandem—With Your Own AI Tool
TandemLoop doesn’t include its own AI. Instead, the app works in tandem with an external, agentic AI tool of your choice—for example, Claude Cowork, Claude Code, Codex, Gemini CLI, or Antigravity. You start this tool separately and let it access your data folder; it then proposes structural changes—so-called proposals. The AI proposes, you decide. No proposal is carried out without your approval.
This turns your data folder into a shared task base: You use it to manage your life and your projects—and share the same base with the AI agents of your choice, which you can even let work alongside you permanently in the background if you like.
You bring the AI. The AI tool isn’t part of TandemLoop but a separate program that you connect—without such a tool, there are no AI proposals. Connecting an AI Tool describes how to connect one, and Working Together Autonomously & Continuously covers ongoing collaboration; everything about the proposal system is in Part 4.
A Guide to This Manual
The manual is organized into the following parts:
- Part 0—Getting Started (these chapters): the interface, quick start, and basic concepts.
- Part 1—Projects & Organization: areas, folders, projects, milestones, tasks, and everything about everyday work.
- Part 2—The View System: saved filter and group views that always show your data from the right angle.
- Part 3—Working with AI: how to connect an external AI tool, keep it running permanently, and link AI projects directly to TandemLoop.
- Part 4—The Proposal System: how proposals are created and how you read, control, approve, or reject them.
- Part 5—In Depth & Reference: settings, keyboard shortcuts, the file format, and a complete glossary.
If you want to get started right away, jump straight to Quick Start in 5 Minutes.