Mode switch Plan -> Code still behaves like Plan

[0xdeafbeef]

What version of Codex is running?

codex-cli 0.92.0

What subscription do you have?

pro

Which model were you using?

No response

What platform is your computer?

Linux 6.18.0-364.vanilla.fc43.x86_64 x86_64 unknown

What terminal emulator and version are you using (if applicable)?

No response

What issue are you seeing?

1. Start a session in Code mode.
2. Switch to Plan mode (shift‑tab).
3. Switch back to Code mode.
4. Ask for an execution command (e.g., “go”).
   Observed: agent claims it’s still in Plan mode and refuses execution.
   Workaround: shift‑tab to Plan and back fixes it.

• Execution is blocked in Plan Mode despite user saying go; must respond with a status update that
  execution can't proceed until mode switches, without asking questions directly.

  Preparing user confirmation prompt

  Planning to request user confirmation to proceed with execution once mode switches, asking
  explicitly to confirm running commands now.

• I’m still in Plan Mode, which forbids executing commands. Please switch me back to code mode

What steps can reproduce the bug?

• Plan mode instruction injected at 2026‑01‑29T18:04:55.152Z (developer message
  <collaboration_mode>).
• Turn context later switches to Code mode at 2026‑01‑29T18:53:37.015Z (collaboration_mode:
  { mode: "code" }).
• Despite that, at 2026‑01‑29T20:09:32.854Z the agent reasons “Execution is blocked in Plan Mode
  …” and emits a request_user_input tool call and message stating it is still in Plan Mode.

What is the expected behavior?

Shift tab removes prev instructions

Additional information

thread ID 019c0aed-2138-7b32-acf5-f3fb174f84f3

[swordfish444]

@etraut-openai This looks like the same underlying issue as #9997 (Plan-mode instructions still influencing behavior after switching back to Code). This report has a nice timestamped repro; suggest consolidating the details into #9997 and closing this as a dup.

[yuvrajangadsingh]

Root Cause Analysis

I investigated the collaboration mode templates and found the issue:

Plan mode template (codex-rs/core/templates/collaboration_mode/plan.md) states:

"You are in Plan Mode until a developer message explicitly ends it.
Plan Mode is not changed by user intent, tone, or imperative language."

Code mode template (codex-rs/core/templates/collaboration_mode/code.md) only says:

"you are now in code mode."

When switching Plan→Code, the Code mode instruction doesn't explicitly end Plan mode - it just announces Code mode. The model follows Plan mode's instruction to persist until an explicit end message.

Proposed Fix

Update code.md to explicitly end Plan mode:

Plan Mode is now ended. You are in Code mode.
You may now execute commands, edit files, and perform mutating actions.

This ensures the model receives an unambiguous signal that Plan mode rules no longer apply.

Repro Steps (from issue)

1. Start in Code mode
2. Switch to Plan mode (shift+tab)
3. Switch back to Code mode
4. Ask for execution → agent refuses, claims still in Plan mode

Thread ID: 019c0aed-2138-7b32-acf5-f3fb174f84f3

[yuvrajangadsingh]

Note: I see @swordfish444 mentioned this may be a dup of #9997, which was marked as mitigated.

However, since the issue persists in 0.92.0, my analysis above might explain why the fix was incomplete - the code.md template still doesn't explicitly end Plan mode, so the model continues following Plan mode's instruction to persist "until a developer message explicitly ends it."

If this is indeed a regression or incomplete fix of #9997, the root cause analysis above may help identify what was missed.

[charley-oai]

Hey @0xdeafbeef have you noticed this on newer versions? I was unable to repro this even on v0.92.0 following your instructions:

Start a session in Code mode.
Switch to Plan mode (shift‑tab).
Switch back to Code mode.
Ask for an execution command (e.g., “go”).
Observed: agent claims it’s still in Plan mode and refuses execution.
Workaround: shift‑tab to Plan and back fixes it.

I worry the behavior is non-deterministic. Did it happen every time for you? Or only sometimes?

[charley-oai]

If non-deterministic than it may just be an issue with the code mode developer instructions (being too subtle) as @yuvrajangadsingh has suggested. But in the rollout of the thread you posted, it looked like the model was getting confused by repetitive insertion of the plan mode instructions, which makes me think there was some bug causing the plan mode instructions to be reinserted at the wrong times (in which case updating the code mode prompt wouldn't fix).

[0xdeafbeef]

Hey @0xdeafbeef have you noticed this on newer versions? I was unable to repro this even on v0.92.0 following your instructions:

Start a session in Code mode.
Switch to Plan mode (shift‑tab).
Switch back to Code mode.
Ask for an execution command (e.g., “go”).
Observed: agent claims it’s still in Plan mode and refuses execution.
Workaround: shift‑tab to Plan and back fixes it.

I worry the behavior is non-deterministic. Did it happen every time for you? Or only sometimes?

Happened in some latest alpha from today. Also there is an issue when you switch plan -> code and it tries to use ask questions tool, but it's available only in a plan mode.

Also it pretty often just states that it's ready to impl plan and asks to manually switch to code mode.

I think that it's the problem of me doing several edit rounds in a single context window without using /new.

[charley-oai]

Hopefully this PR will improve: #10545