Codex Projects Can Now Include Multiple Folders: Keep Your Code and Documentation Together

July 28, 2026Updated: July 28, 2026Articles

Codex local projects can now include multiple folders. OpenAI Developers announced the update on July 24, 2026 (Japan time), making it possible to work across related code, documentation, and reference files from a single project.

Until now, Codex was generally centered on one folder or repository. That created extra work when a website’s code lived in one project folder while its specifications and planning notes were stored somewhere else. You had to explain where the files were each time, or copy the same documents into the code project.

Adding related folders to a Codex project

The update lets you register multiple folders within one Codex project. Alongside the primary folder, you can treat locations like these as related folders:

Source code for an app or website
Specifications, planning documents, and design references
Test data and sample files
Documentation and reference material stored elsewhere

Because Codex can read and write across the related folders in a project, you can ask it to “read this specification and update the implementation” without moving between separate workspaces. For AIじてん, that means the website itself and its planning and editorial notes can be referenced from the same project.

The Git root remains the primary folder

There is an important distinction here: adding multiple folders does not merge their Git roots into one repository. A Codex project still has a primary folder at its center, and that folder remains the project’s Git root.

In other words, this is not a way to combine several repositories. It is a way to make related material easier to access from one unit of work. When reviewing commits or branches, use the primary folder as your starting point, and separately confirm which repository owns any changes made in a related folder.

How this could work for AIじてん

For example, you could keep the AIじてん WordPress theme and plugins in the primary folder, then add related folders containing:

The article and glossary editing guide
The site’s concept and design direction
The pre-launch checklist
Planning notes for future features

With that setup, you can ask Codex to “check the article rules before creating a draft” or “update the theme according to this design direction” without explaining the file locations every time. The benefit is not just giving Codex more code; it also gives it access to the reasoning and decisions behind the code.

However, adding a related folder does not mean Codex will automatically read every document in it. It is still useful to state which files should be treated as requirements and which folders Codex may edit. Put those rules in your request or in a project instruction file, and make the scope explicit alongside the Codex project settings.

Start with “code plus specifications”

A good first test is to combine a source-code folder with a folder containing its specifications.

Open the primary folder or Git repository in Codex.
Add the related folder from the project settings.
Tell Codex what each folder contains and what role it plays.
Ask it to review the specification, propose changes, and only then implement them.

Rather than assigning a large change immediately, start with a request such as “read the related documents and list the differences from the current implementation.” That makes it easier to confirm what Codex can see and how changes in each folder appear in Git.

The more convenient the project becomes, the more carefully you should choose its folders

Multiple-folder support removes the need to duplicate reference material, which is genuinely useful. At the same time, folders added to a project become part of the area Codex can read and write. Do not add every location on your computer just because it is convenient; choose only the files and folders the task actually needs, especially when personal or confidential information is involved.

Also remember that a change made in a related folder may not appear as a change in the primary folder’s Git diff. After a task, check the state of each folder and create commits or backups in the appropriate repository when necessary.

Summary

Codex projects can now bring code, specifications, documentation, and reference files together as one working context. The key detail is that the primary folder remains the Git root.

For people who manage a site and its planning notes separately, like AIじてん, the biggest benefit is being able to reference the background information without copying it into the codebase. Start with a small “code plus specifications” setup, then decide your own rules for which folders Codex should read and which ones it may modify.