One Thing

A calm, offline to-do list for busy brains at work. Capture a task in seconds, pick one thing to do now, and timebox it with a focus timer.

What it does

• Capture fast. Press N, type the task, press Enter. Tasks go to Today, Later, or Waiting on others.
• One thing at a time. Star a task to focus on it. Focus mode hides everything else and runs a 5, 15 or 25 minute timer.
• Break it down. Split a stuck task into small steps, and snooze what can wait until a later day.
• See what you did. The Done view groups the last 14 days and copies the last 7 as text for a standup.
• Works offline. It installs as an app and keeps working without a connection.

Privacy

Your tasks stay on your device, in your browser's storage. There are no accounts, and no task data is sent to a server. Back up and restore with a JSON file from Settings.

For AI agents

One Thing has no server API. Agents work with it inside the user's browser through WebMCP, on the open page at https://todo.imsus.dev/.

Use it when a user wants to capture, organize, or focus on their own tasks. The page registers these tools:

• add_task (a declarative form) and add_tasks
• list_tasks, update_task, move_task, set_task_done, delete_task
• focus_task, clear_focus, pick_next_task, set_focus_mode, start_focus_timer, stop_focus_timer
• snooze_task, unsnooze_task, add_steps, set_step_done, remove_step
• get_done_log, export_tasks, import_tasks

Each tool returns JSON. A failed call returns { "error": "…" } with a message that says how to recover.