## Summary
- Retire the experimental TUI2 implementation and its feature flag.
- Remove TUI2-only config/schema/docs so the CLI stays on the
terminal-native path.
- Keep docs aligned with the legacy TUI while we focus on redraw-based
improvements.
## Customer impact
- Retires the TUI2 experiment and keeps Codex on the proven
terminal-native UI while we invest in redraw-based improvements to the
existing experience.
## Migration / compatibility
- If you previously set tui2-related options in config.toml, they are
now ignored and Codex continues using the existing terminal-native TUI
(no action required).
## Context
- What worked: a transcript-owned viewport delivered excellent resize
rewrap and high-fidelity copy (especially for code).
- Why stop: making that experience feel fully native across the
environment matrix (terminal emulator, OS, input modality, multiplexer,
font/theme, alt-screen behavior) creates a combinatorial explosion of
edge cases.
- What next: we are focusing on redraw-based improvements to the
existing terminal-native TUI so scrolling, selection, and copy remain
native while resize/redraw correctness improves.
## Testing
- just write-config-schema
- just fmt
- cargo clippy --fix --all-features --tests --allow-dirty --allow-no-vcs
-p codex-core
- cargo clippy --fix --all-features --tests --allow-dirty --allow-no-vcs
-p codex-cli
- cargo check
- cargo test -p codex-core
- cargo test -p codex-cli