Support reusable existing worktrees as project-level workspaces, decoupled from session lifecycle

Title: Support reusable existing worktrees as project-level workspaces, decoupled from session lifecycle

I’d like to suggest a workflow improvement around Codex sessions and git worktrees.

Background

This is especially important for users who keep long-lived frontend/backend worktrees with dependencies, local environment state, and code indexes already prepared.

Codex already has the ability to create a new worktree for a session. That’s useful.

However, in long-running real projects, a worktree is often more than a temporary task folder. It becomes a reusable development workspace with:

• installed dependencies
• built local environment state
• code indexes such as CodeGraph
• IDE/tool caches
• stable frontend/backend setup for a specific development lane

Examples:

• a long-lived frontend worktree
• a long-lived backend worktree
• a long-lived module/special-topic worktree

Current problem

Today, session lifecycle and worktree lifecycle feel too tightly coupled.

There are two related issues:

1. A new session cannot cleanly bind to an already existing reusable worktree while still belonging to the main project

If I launch a new session from the main project root, then tell the agent to work inside another existing worktree path, the actual execution may happen there, but the Codex UI/project context still looks tied to the main tree.

That causes problems because branch / git status / PR info / CodeGraph / workspace context can become visually or logically misaligned.

If I instead launch directly from the worktree, the session becomes attached to that worktree as if it were a separate project, which fragments project history/memory.

What I want is:

• session belongs to the main project
• execution workspace is an already existing worktree
• git/branch/PR/status/indexing context follows that worktree
• project identity remains the main project

2. Archiving/completing a session should not force the associated worktree to become disposable

If a session created a worktree and the task is done, I may want to:

• close the branch
• archive the session
• keep the worktree

because the worktree already has all dependencies, indexes, and local environment prepared.

Right now, the workflow feels like the worktree is treated as a temporary byproduct of the session, instead of a reusable project-level workspace.

That makes it hard to reuse the same prepared worktree for the next task.

Why this matters

For real development workflows, especially multi-branch / multi-module / long-lived projects, reusable worktrees are important for efficiency.

Recreating worktrees repeatedly means redoing or revalidating:

• dependency installation
• local environment prep
• code indexing
• tool caches
• project-specific setup

This becomes especially painful when the worktree is intentionally kept as a stable lane, e.g. “frontend workspace” or “backend workspace”.

Requested behavior

I’d love Codex to support a model like this:

Project

The logical project identity, memory/history grouping, and top-level project context.

Session

A task-specific conversation / execution run.

Workspace / Worktree

The actual execution environment, which can be long-lived and reusable across multiple sessions.

Desired capabilities

1. When creating a new session, allow selecting an already existing worktree as the execution workspace.
2. Keep the session attached to the main project identity, not split into a separate project just because the worktree lives elsewhere.
3. In the UI, show git branch / PR / status / workspace information based on the selected worktree, not the main tree.
4. When archiving/completing a session, provide an explicit choice:

• archive session and delete worktree
• archive session but keep worktree

1. Allow future sessions to re-bind to that preserved worktree.

Concrete example

Main project:
/Users/gpp/project/gitee/jwxt

Reusable long-lived frontend worktree:
/Users/gpp/.codex/worktrees/39d7/jwxt

Desired workflow:

• Task A session uses that worktree
• Task A finishes
• branch is merged/closed
• session is archived
• worktree is kept
• Task B starts later
• new session binds again to /Users/gpp/.codex/worktrees/39d7/jwxt
• UI shows the real branch / git status / PR / CodeGraph context of that worktree
• but the session still belongs to the main jwxt project

Summary

The main request is:

Please treat worktrees as reusable project-level execution environments, not only as disposable session byproducts.

Filed with help from Codex on behalf of the reporter.