Your To-Do List Doesn’t Need to Live in One App: Dividing the Work Between Codex, Obsidian, and Todoist

July 23, 2026Updated: July 25, 2026Articles

A to-do list should live in one app. For a long time, I assumed that was the obvious way to manage tasks.

That changed after I started using Codex in my daily work and letting it read my project notes in Obsidian. I realized that task management was actually asking two different things of me.

One is a place to preserve the reasoning behind a task and what I want to try next. The other is a system that reliably reminds me at a specific time. Today, I leave the former to Obsidian and Codex, and the latter to Todoist.

I did not replace my to-do app—I split its responsibilities

This is not a story about moving every task from Todoist to Obsidian. I still use Todoist, and I expect to keep using it.

What changed was the division of labor.

Obsidian: Stores background information, ideas in progress, and things I may want to try later
Codex: Reads those notes, organizes the current situation, and helps me decide what to work on next
Todoist: Handles deadlines, notifications, and recurring schedules

Put simply, Obsidian manages context, while Todoist manages time. Codex sits on top of the context and helps turn it into action.

If AI reads the notes, not everything needs a checkbox

A traditional to-do list is designed to be scanned by a person. Checkboxes make it easy to see what is unfinished and what has already been completed.

But if I can ask Codex, “What should I prioritize next?”, every useful note does not have to start life as a perfectly formatted task.

Notes such as “This is on hold until the design is decided,” “Resume from this point next time,” or “Try these three ideas if there is time” can still provide enough context for Codex to help. A clear heading and a short explanation often matter more than turning every line into a checkbox.

Bulleted lists are still useful, of course. Obsidian uses Markdown, so starting one is as simple as typing a hyphen and a space. The important change is that I no longer feel obliged to convert every thought into a neatly processed task the moment it appears.

Task capture now happens at the end of an AI conversation

Opening a separate app every time an idea appears creates more friction than it seems.

Now, I often discuss a problem with Codex or Claude first. After reviewing the suggestions, I might say, “Remove this idea, and add the rest to the project notes.” That conversation becomes the raw material for the next set of tasks.

The advantage is not just faster entry. The decision and the reason behind it remain together. When I return to the project later, Codex can read both what I chose and why I chose it.

I still write things down manually when that is faster. Obsidian is flexible enough for both approaches, which is one reason the system has felt comfortable rather than restrictive.

Anything that must notify me stays in Todoist

Some tasks are less about context and more about being reminded at exactly the right time.

Work that repeats every week
Payment dates
A message that must be sent on a particular day

These still belong in Todoist. Its natural-language date entry and recurring schedules are more convenient than trying to reproduce a reminder system inside a note-taking app.

Separating “information I need in order to think” from “things that must notify me” has made my Todoist list smaller and clearer. It has also made me wonder whether I still need its paid plan. I will decide that only after I have moved enough data and checked the current plan limits.

Three questions decide where a task belongs

When I am unsure where to put something, I use three questions.

Do I need a notification on a specific date or at a specific time?
If yes, it goes in Todoist.
Do I need to preserve the background or the reasoning behind it?
If yes, it goes in the project notes in Obsidian.
Is the next action still undecided?
If yes, I leave it as prose and ask Codex to help me sort it out later.

Some work needs both. In that case, I put a short reminder in Todoist and keep the details in Obsidian. One tool does not have to carry the entire task.

Do not migrate everything on day one

Moving an entire task list at once would create a large cleanup project of its own.

A safer starting point is to move only projects with no hard deadline and the “someday” items that benefit from background notes. Tasks due tomorrow and monthly routines can remain in Todoist.

After a few weeks, ask Codex what you should do next and see whether it can reliably find the relevant work. If it cannot, review file names, headings, and note locations before adding more checkboxes. Better structure usually helps more than a larger list.

It is also worth limiting the folders an AI tool can access and keeping passwords, API keys, and other secrets out of project notes.

A to-do list becomes a division of labor

With AI in the workflow, a to-do list no longer has to be a single sheet that I scan every morning.

Obsidian preserves context. Codex organizes it. Todoist tells me when it is time to act.

I have not stopped using Todoist. I have simply stopped asking it to hold everything. Moving roughly half of my task management was enough to make the whole system feel lighter.