Support Plan mode in the CLI and TS SDK

[gsabran]

What variant of Codex are you using?

CLI, ts SDK

What feature would you like to see?

The CLI (and the TS SDK that uses the CLI) don't support plan mode. It would be great if they did!

Additional information

No response

[etraut-openai]

The CLI does support plan mode. Just use the /plan slash command to toggle.

[gsabran]

I meant in headless mode, ie the CLI doesn't have a parameter to be prompted in plan mode (updated the description)

[gsabran]

There seem to be a comment indicating interest to support this:

codex/codex-rs/core/src/codex.rs

Lines 449 to 450 in 745c48b

	// TODO (aibrahim): Consolidate config.model and config.model_reasoning_effort into config.collaboration_mode
	// to avoid extracting these fields separately and constructing CollaborationMode here.

[gsabran]

I made a PR, I don't think I can open it as I'm not a collaborator to this repo:

https://github.com/openai/codex/compare/main...gsabran:gui/plan-exec?expand=1

[g-imhoff]

Also very interested about getting this !

[0xble]

Strong +1 on this.

The missing piece is not interactive /plan, it is a first-class startup parameter for Plan mode.

What would be most ergonomic is something like:

• codex --plan
• codex --plan "investigate this repo and propose a fix"

Possibly also:

• codex exec --plan "..."

Why this matters:

• /plan only works after the session starts
• wrappers and orchestrators cannot express startup intent cleanly
• prompt-level /plan shims are brittle and less discoverable than a real flag
• this matches precedent from Claude, which exposes startup plan mode via --permission-mode plan

I would treat this as distinct from "Plan mode exists" and closer to "Plan mode is not addressable as a first-class CLI startup mode".