## What version of Codex CLI is running? - `rust-v0.146.0-alpha.10` ## What subscription do you have? - ChatGPT Pro 20x. ## Which model were you using? - `gpt-5.6-sol` ## What terminal emulator and version are you using? - Alacritty with Codex running inside tmux. ## What issue are you seeing? - I locally adjusted the `code-mode-exec` instructions to guide the model to write JavaScript that invokes independent nested tools concurrently. - The generated Code Mode call and its nested tool

TUI flashes continuously during bursts of Code Mode tool activity

Open 💬 0 comments Opened Jul 25, 2026 by 92645417d9e5c763259dbebc306e3e

I locally adjusted the code-mode-exec instructions to guide the model to write JavaScript that invokes independent nested tools concurrently.
The generated Code Mode call and its nested tool calls successfully complete the requested task.
During a burst of concurrent Code Mode tool activity, the TUI rapidly inserts many Ran and Explored entries while the lower portion of the interface repeatedly changes between one and multiple lines.
The repeated layout changes cause the entire terminal to flash at high frequency and can flood the tmux scrollback buffer.
The problem is therefore the unstable and continuously flashing TUI presentation during otherwise successful concurrent tool execution.

Start Codex CLI in a tmux session.
Configure the local code-mode-exec instructions to guide the model to generate JavaScript that invokes independent nested tools concurrently.
Ask Codex to perform a task that results in many concurrent shell or read-only nested tool calls.
Keep the TUI visible while the nested tool calls start and complete in quick succession.
Confirm that the task completes, while the transcript receives many Ran or Explored entries and the lower interface repeatedly changes height, causing continuous terminal flashing.

Supported concurrent Code Mode tool activity should render without rapid whole-terminal flashing or repeated one-line-to-multiline layout oscillation.
Concurrent nested tool activity should be collapsed in the TUI like other collapsed tool output, with the existing Ctrl+T transcript view available to inspect the complete details.