After writing about setting Claude Code status line with Ruby, I wanted to see if the same thing is possible for Codex and dig a bit more.

First, all 3 let you set the status line globally, at the user level, or locally per project.

Second, the way they work is different, and only Claude accepts a command as I described it in the previous article.

Here is a summary of the findings so far:

Thus, a Ruby script can be used directly only in Claude Code, while Codex only allows specific items to be displayed there, and opencode will need a JavaScript entry point that can run a Ruby script if you want it to.

Codex

Codex will read the global config from ~/.codex/config.toml and then load it if it exists in .codex/config.toml from the project folder where it runs.

The settings can be defined as:

[tui]
status_line = ["model-with-reasoning", "current-dir", "five-hour-limit", "weekly-limit", "git-branch", "context-used", "context-window-size", "fast-mode"]
status_line_use_colors = true

You cannot define a custom script (or maybe I could not find it quickly, but as Codex is open source, you can dig more if you want in their source code), so you have to pick from what Codex allows you to choose and then put those in the order that you want to see them.

The config documentation says this about the status line:

Ordered list of TUI footer status-line item identifiers. null turns off the status line.

List of names you can use in Codex status line

I could not find in the documentation the exact list of identifiers, so I dug it in the Codex source and found this list of possible status line items at StatusLineItem from version 0.146.1 with 26 items:

approval-mode          branch-changes        codex-version
context-remaining      context-used          context-window-size
current-dir            fast-mode             five-hour-limit
git-branch             model                 model-with-reasoning
permissions            project-name          pull-request-number
raw-output             reasoning             run-state
task-progress          thread-id             thread-title
total-input-tokens     total-output-tokens   used-tokens
weekly-limit           workspace-headline

Please consider this a discovery from the source code. Since there is no official documentation for this, there is no interface contract to keep it as it is

Codex will not check the strings you add to status_line configuration

I made a config with a non-existing name totally-bogus-item:

[tui]
status_line = ["current-dir", "git-branch", "totally-bogus-item"]

and then I run the doctor command:

CODEX_HOME=/tmp/codexhome codex doctor --summary

And the configuration section came back happy:

Configuration
  ✓ config       loaded

This may be a bug, but I don’t know. But you should not rely on codex doctor to verify that the names you added there are correct.

Just check what the status line looks like, and may I suggest adding items incrementally, one by one.

Practical ideas from this

I like the Claude Code approach more in this case than Codex because you can do a lot more with status line processing than Codex can by default.

For example, having the session_id there, I already changed my statusline.rb file to read the session and tell me the last tool that was executed, how many prompts I have written so far, and the context used in the last turn.

Codex does not give this option. You mostly get what the team already implemented. Of course, as it is open source, you can always fork and implement what you need and then make a PR back to the upstream. What they offer is more performant than computing things from the session file.

I would still like to have something like status_line_command in Codex that behaves similarly to how Claude Code does.