## Stack
- **Current: #24489 [1 of 2]** - render markdown tables in app style.
- **Stacked follow-up: #24636 [2 of 2]** - render cramped markdown
tables as key/value records.
## Why
Markdown tables currently render as boxed terminal grids, which gives
ordinary assistant output a heavier visual treatment than surrounding
rich text. This row-separated layout is the best match for how the App
renders tables, while accented headers remain distinguishable even when
a terminal font renders bold subtly.
<table>
<tr><td>
<p align="center">Codex CLI - Before</p>
<img width="1722" height="742" alt="CleanShot 2026-05-25 at 18 46 17"
src="https://github.com/user-attachments/assets/f673d92a-ebd8-46e2-b414-3d985e41b6a4"
/>
</td></tr>
<tr><td>
<p align="center">Codex CLI - After</p>
<img width="1720" height="957" alt="image"
src="https://github.com/user-attachments/assets/36a3d331-bea1-439b-b5be-e97b0731bd6f"
/>
</td></tr>
<tr><td>
<p align="center">Codex App</p>
<img width="979" height="1293" alt="CleanShot 2026-05-25 at 18 45 04"
src="https://github.com/user-attachments/assets/7d97cae0-9256-4f6e-a4b3-8b8f22b0d901"
/>
</td></tr>
</table>
## What Changed
- Render markdown tables as padded, aligned rows without an enclosing
box.
- Style table headers with the active syntax-theme accent plus bold
text, while keeping separators low contrast and theme-aware.
- Use a segmented heavy header rule and thin body-row rules, preserving
wrapping, narrow-width fallback, streaming parity, and rich-history
rendering.
- Update focused assertions and snapshots for the final table layout.
## How to Test
1. Render a markdown table in the TUI with several rows and columns.
2. Confirm the header uses the active theme accent, rows use
one-character interior padding, and the table has no enclosing box.
3. Confirm the header is followed by segmented `━` rules and multiple
body rows are separated by muted segmented `─` rules.
4. Render the same table while streaming and in history/raw-mode
toggles; the final rich layout should remain stable.
5. Render a narrow table with long content and verify wrapping or pipe
fallback does not overflow.
## Validation
- `just test -p codex-tui table`
- `just test -p codex-tui streaming::controller::tests`
- `just argument-comment-lint-from-source -p codex-tui -- --all-targets`
- `just fix -p codex-tui`
- `just fmt`
`just test -p codex-tui` was also run after accepting the snapshots; it
fails only in the unrelated existing guardian app tests
`update_feature_flags_disabling_guardian_clears_review_policy_and_restores_default`
and
`update_feature_flags_disabling_guardian_clears_manual_review_policy_without_history`.
## Why
On light terminal backgrounds, selected rows in several TUI pickers were
rendered with the same bright cyan accent used on dark themes. Against
the light menu surface, that made the current selection hard to
distinguish at a glance.
<table><tr>
<td>
<p align="center">Before</p>
<img width="1109" height="864" alt="SCR-20260509-nmtz"
src="https://github.com/user-attachments/assets/b31ce0d0-19c2-4bdd-a220-7acc77bd8e8e"
/>
</td>
<td>
<p align="center">After</p>
<img width="1164" height="844" alt="SCR-20260509-nmox"
src="https://github.com/user-attachments/assets/7b3fede0-4739-4a9f-a979-cdbb7451841f"
/>
</td>
</tr></table>
## What changed
- Added a shared background-aware accent style for active/selected TUI
controls.
- Use a darker cyan-family accent on light backgrounds while preserving
the existing bright cyan accent on dark or unknown backgrounds.
- Reused that accent across shared picker rows and the custom
selection-like surfaces that had drifted separately: picker tabs, hooks
browsing, external-agent migration choices, and /keymap affordances.
- Added focused tests for the light/dark accent rule and rendered
selected-row styling.
## How to Test
1. Start Codex in a terminal using a light background theme.
2. Type `/` to open the slash-command picker and move the selection
through a few rows.
3. Confirm that the selected row is visibly colored with strong contrast
instead of blending into the popup surface.
4. Open `/keymap` and confirm the active tab, selected rows, and picker
hint accents use the same light-theme accent treatment.
5. In a dark terminal theme, repeat the slash-picker check and confirm
the existing bright cyan selection styling is preserved.
Targeted tests:
- `cargo test -p codex-tui accent_style_uses_`
- `cargo test -p codex-tui selected_rows_use_the_shared_accent_style`
- `cargo test -p codex-tui
selected_event_rows_use_the_shared_accent_style`
Notes:
- A full `cargo test -p codex-tui` run reached the end of the suite but
hit an unrelated existing stack overflow in
`tests::fork_last_filters_latest_session_by_cwd_unless_show_all`.
This is a follow-up to https://github.com/openai/codex/pull/15922. That
previous PR deleted the old `tui` directory and left the new
`tui_app_server` directory in place. This PR renames `tui_app_server` to
`tui` and fixes up all references.
This is the part 1 of 2 PRs that will delete the `tui` /
`tui_app_server` split. This part simply deletes the existing `tui`
directory and marks the `tui_app_server` feature flag as removed. I left
the `tui_app_server` feature flag in place for now so its presence
doesn't result in an error. It is simply ignored.
Part 2 will rename the `tui_app_server` directory `tui`. I did this as
two parts to reduce visible code churn.
## Summary
- Stream proposed plans in Plan Mode using `<proposed_plan>` tags parsed
in core, emitting plan deltas plus a plan `ThreadItem`, while stripping
tags from normal assistant output.
- Persist plan items and rebuild them on resume so proposed plans show
in thread history.
- Wire plan items/deltas through app-server protocol v2 and render a
dedicated proposed-plan view in the TUI, including the “Implement this
plan?” prompt only when a plan item is present.
## Changes
### Core (`codex-rs/core`)
- Added a generic, line-based tag parser that buffers each line until it
can disprove a tag prefix; implements auto-close on `finish()` for
unterminated tags. `codex-rs/core/src/tagged_block_parser.rs`
- Refactored proposed plan parsing to wrap the generic parser.
`codex-rs/core/src/proposed_plan_parser.rs`
- In plan mode, stream assistant deltas as:
- **Normal text** → `AgentMessageContentDelta`
- **Plan text** → `PlanDelta` + `TurnItem::Plan` start/completion
(`codex-rs/core/src/codex.rs`)
- Final plan item content is derived from the completed assistant
message (authoritative), not necessarily the concatenated deltas.
- Strips `<proposed_plan>` blocks from assistant text in plan mode so
tags don’t appear in normal messages.
(`codex-rs/core/src/stream_events_utils.rs`)
- Persist `ItemCompleted` events only for plan items for rollout replay.
(`codex-rs/core/src/rollout/policy.rs`)
- Guard `update_plan` tool in Plan Mode with a clear error message.
(`codex-rs/core/src/tools/handlers/plan.rs`)
- Updated Plan Mode prompt to:
- keep `<proposed_plan>` out of non-final reasoning/preambles
- require exact tag formatting
- allow only one `<proposed_plan>` block per turn
(`codex-rs/core/templates/collaboration_mode/plan.md`)
### Protocol / App-server protocol
- Added `TurnItem::Plan` and `PlanDeltaEvent` to core protocol items.
(`codex-rs/protocol/src/items.rs`, `codex-rs/protocol/src/protocol.rs`)
- Added v2 `ThreadItem::Plan` and `PlanDeltaNotification` with
EXPERIMENTAL markers and note that deltas may not match the final plan
item. (`codex-rs/app-server-protocol/src/protocol/v2.rs`)
- Added plan delta route in app-server protocol common mapping.
(`codex-rs/app-server-protocol/src/protocol/common.rs`)
- Rebuild plan items from persisted `ItemCompleted` events on resume.
(`codex-rs/app-server-protocol/src/protocol/thread_history.rs`)
### App-server
- Forward plan deltas to v2 clients and map core plan items to v2 plan
items. (`codex-rs/app-server/src/bespoke_event_handling.rs`,
`codex-rs/app-server/src/codex_message_processor.rs`)
- Added v2 plan item tests.
(`codex-rs/app-server/tests/suite/v2/plan_item.rs`)
### TUI
- Added a dedicated proposed plan history cell with special background
and padding, and moved “• Proposed Plan” outside the highlighted block.
(`codex-rs/tui/src/history_cell.rs`, `codex-rs/tui/src/style.rs`)
- Only show “Implement this plan?” when a plan item exists.
(`codex-rs/tui/src/chatwidget.rs`,
`codex-rs/tui/src/chatwidget/tests.rs`)
<img width="831" height="847" alt="Screenshot 2026-01-29 at 7 06 24 PM"
src="https://github.com/user-attachments/assets/69794c8c-f96b-4d36-92ef-c1f5c3a8f286"
/>
### Docs / Misc
- Updated protocol docs to mention plan deltas.
(`codex-rs/docs/protocol_v1.md`)
- Minor plumbing updates in exec/debug clients to tolerate plan deltas.
(`codex-rs/debug-client/src/reader.rs`, `codex-rs/exec/...`)
## Tests
- Added core integration tests:
- Plan mode strips plan from agent messages.
- Missing `</proposed_plan>` closes at end-of-message.
(`codex-rs/core/tests/suite/items.rs`)
- Added unit tests for generic tag parser (prefix buffering, non-tag
lines, auto-close). (`codex-rs/core/src/tagged_block_parser.rs`)
- Existing app-server plan item tests in v2.
(`codex-rs/app-server/tests/suite/v2/plan_item.rs`)
## Notes / Behavior
- Plan output no longer appears in standard assistant text in Plan Mode;
it streams via `PlanDelta` and completes as a `TurnItem::Plan`.
- The final plan item content is authoritative and may diverge from
streamed deltas (documented as experimental).
- Reasoning summaries are not filtered; prompt instructs the model not
to include `<proposed_plan>` outside the final plan message.
## Codex Author
`codex fork 019bec2d-b09d-7450-b292-d7bcdddcdbfb`
Instead of querying all 256 terminal colors on startup, which was slow
in some terminals, hardcode the default xterm palette.
Additionally, tweak the shimmer so that it blends between default_fg and
default_bg, instead of "dark gray" (according to the terminal) and pure
white (regardless of terminal theme).
Felipe Coury