## Problem
Diff lines used only foreground colors (green/red) with no background
tinting, making them hard to scan. The gutter (line numbers) also had no
theme awareness — dimmed text was fine on dark terminals but unreadable
on light ones.
## Mental model
Each diff line now has four styled layers: **gutter** (line number),
**sign** (`+`/`-`), **content** (text), and **line background** (full
terminal width). A `DiffTheme` enum (`Dark` / `Light`) is selected once
per render by probing the terminal's queried background via
`default_bg()`. A companion `DiffColorLevel` enum (`TrueColor` /
`Ansi256` / `Ansi16`) is derived from `stdout_color_level()` and gates
which palette is used. All style helpers dispatch on `(theme,
DiffLineType, color_level)` to pick the right colors.
| Theme Picker Wide | Theme Picker Narrow |
|---|---|
| <img width="1552" height="1012" alt="image"
src="https://github.com/user-attachments/assets/231b21b7-32d4-4727-80ed-7d01924954be"
/> | <img width="795" height="1012" alt="image"
src="https://github.com/user-attachments/assets/549cacdf-daec-43c9-ad64-2a28d16d140e"
/> |
| Dark BG - 16 colors | Dark BG - 256 colors | Dark BG - True Colors |
|---|---|---|
| <img width="1552" height="1012" alt="dark-16colors"
src="https://github.com/user-attachments/assets/fba36de3-c101-47d4-9e63-88cdd00410d0"
/> | <img width="1552" height="1012" alt="dark-256colors"
src="https://github.com/user-attachments/assets/f39e4307-c6b0-49c4-b4fe-bd26d3d8e41c"
/> | <img width="1552" height="1012" alt="dark-truecolor"
src="https://github.com/user-attachments/assets/1af4ec57-04bf-4dfb-8a44-0ab5e5aaaf18"
/> |
| Light BG - 16 colors | Light BG - 256 colors | Light BG - True Colors
|
|---|---|---|
| <img width="1552" height="1012" alt="light-16colors"
src="https://github.com/user-attachments/assets/2b5423d1-74b4-4b1e-8123-7c2488ff436b"
/> | <img width="1552" height="1012" alt="light-256colors"
src="https://github.com/user-attachments/assets/c94cff9a-8d3e-42c9-bbe7-079da39953a8"
/> | <img width="1552" height="1012" alt="light-truecolor"
src="https://github.com/user-attachments/assets/f73da626-725f-4452-99ee-69ef706df2c6"
/> |
## Non-goals
- No runtime theme switching beyond what `default_bg()` already
provides.
- No change to syntax highlighting theme selection or the highlight
module.
## Tradeoffs
- Three fixed palettes (truecolor RGB, 256-color indexed, 16-color
named) are maintained rather than using `best_color` nearest-match. This
is deliberate: `supports_color::on_cached(Stream::Stdout)` can misreport
capabilities once crossterm enters the alternate screen, so hand-picked
palette entries give better visual results than automatic quantization.
- Delete lines in the syntax-highlighted path get `Modifier::DIM` to
visually recede compared to insert lines. This trades some readability
of deleted code for scan-ability of additions.
- The theme picker's diff preview sets `preserve_side_content_bg: true`
on `ListSelectionView` so diff background tints survive into the side
panel. Other popups keep the default (`false`) to preserve their
reset-background look.
## Architecture
- **Color constants** are module-level `const` items grouped by palette
tier: `DARK_TC_*` / `LIGHT_TC_*` (truecolor RGB tuples), `DARK_256_*` /
`LIGHT_256_*` (xterm indexed), with named `Color` variants used for the
16-color tier.
- **`DiffTheme`** is a private enum; `diff_theme()` probes the terminal
and `diff_theme_for_bg()` is the testable pure-function version.
- **`DiffColorLevel`** is a private enum derived from `StdoutColorLevel`
via `diff_color_level()`.
- **Palette helpers** (`add_line_bg`, `del_line_bg`, `light_gutter_fg`,
`light_add_num_bg`, `light_del_num_bg`) each take `(DiffTheme,
DiffColorLevel)` or just `DiffColorLevel` and return a `Color`.
- **Style helpers** (`style_line_bg_for`, `style_gutter_for`,
`style_sign_add`, `style_sign_del`, `style_add`, `style_del`) each take
`(DiffLineType, DiffTheme, DiffColorLevel)` or `(DiffTheme,
DiffColorLevel)` and return a `Style`.
- **`push_wrapped_diff_line_inner_with_theme_and_color_level`** is the
innermost renderer, accepting both theme and color level so tests can
exercise any combination without depending on the terminal.
- **Line-level background** is applied via
`RtLine::from(...).style(line_bg)` so the tint extends across the full
terminal width, not just the text content.
- **Theme picker integration**: `ListSelectionView` gained a
`preserve_side_content_bg` flag. When `true`, the side panel skips
`force_bg_to_terminal_bg`, letting diff preview backgrounds render
faithfully.
## Observability
No new logging. Theme selection is deterministic from `default_bg()`,
which is already queried and cached at TUI startup.
## Tests
1. **`DiffTheme` is determined per `render_change` call** — if
`default_bg()` changes mid-render (e.g. `requery_default_colors()`
fires), different file chunks could render with different themes. Low
risk in practice since re-query only happens on explicit user action.
2. **16-color tier uses named `Color` variants** (`Color::Green`,
`Color::Red`, etc.) which the terminal maps to its own palette. On
unusual terminal themes these could clash with the background.
Acceptable since 16-color terminals already have unpredictable color
rendering.
3. **Light-theme `style_add` / `style_del` set bg but no fg** — on light
terminals, non-syntax-highlighted content uses the terminal's default
foreground against a pastel background. If the terminal's default fg
happens to be very light, contrast could suffer. This is an edge case
since light-terminal users typically have dark default fg.
4. **`preserve_side_content_bg` is a general-purpose flag but only used
by the theme picker** — if other popups start using side content with
intentional backgrounds they'll need to opt in explicitly. Not a real
risk today, just a note for future callers.
## Summary
Adds syntax highlighting to the TUI for fenced code blocks in markdown
responses and file diffs, plus a `/theme` command with live preview and
persistent theme selection. Uses syntect (~250 grammars, 32 bundled
themes, ~1 MB binary cost) — the same engine behind `bat`, `delta`, and
`xi-editor`. Includes guardrails for large inputs, graceful fallback to
plain text, and SSH-aware clipboard integration for the `/copy` command.
<img width="1554" height="1014" alt="image"
src="https://github.com/user-attachments/assets/38737a79-8717-4715-b857-94cf1ba59b85"
/>
<img width="2354" height="1374" alt="image"
src="https://github.com/user-attachments/assets/25d30a00-c487-4af8-9cb6-63b0695a4be7"
/>
## Problem
Code blocks in the TUI (markdown responses and file diffs) render
without syntax highlighting, making it hard to scan code at a glance.
Users also have no way to pick a color theme that matches their terminal
aesthetic.
## Mental model
The highlighting system has three layers:
1. **Syntax engine** (`render::highlight`) -- a thin wrapper around
syntect + two-face. It owns a process-global `SyntaxSet` (~250 grammars)
and a `RwLock<Theme>` that can be swapped at runtime. All public entry
points accept `(code, lang)` and return ratatui `Span`/`Line` vectors or
`None` when the language is unrecognized or the input exceeds safety
guardrails.
2. **Rendering consumers** -- `markdown_render` feeds fenced code blocks
through the engine; `diff_render` highlights Add/Delete content as a
whole file and Update hunks per-hunk (preserving parser state across
hunk lines). Both callers fall back to plain unstyled text when the
engine returns `None`.
3. **Theme lifecycle** -- at startup the config's `tui.theme` is
resolved to a syntect `Theme` via `set_theme_override`. At runtime the
`/theme` picker calls `set_syntax_theme` to swap themes live; on cancel
it restores the snapshot taken at open. On confirm it persists `[tui]
theme = "..."` to config.toml.
## Non-goals
- Inline diff highlighting (word-level change detection within a line).
- Semantic / LSP-backed highlighting.
- Theme authoring tooling; users supply standard `.tmTheme` files.
## Tradeoffs
| Decision | Upside | Downside |
| ------------------------------------------------ |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
-----------------------------------------------------------------------------------------------------------------------
|
| syntect over tree-sitter / arborium | ~1 MB binary increase for ~250
grammars + 32 themes; battle-tested crate powering widely-used tools
(`bat`, `delta`, `xi-editor`). tree-sitter would add ~12 MB for 20-30
languages or ~35 MB for full coverage. | Regex-based; less structurally
accurate than tree-sitter for some languages (e.g. language injections
like JS-in-HTML). |
| Global `RwLock<Theme>` | Enables live `/theme` preview without
threading Theme through every call site | Lock contention risk
(mitigated: reads vastly outnumber writes, single UI thread) |
| Skip background / italic / underline from themes | Terminal BG
preserved, avoids ugly rendering on some themes | Themes that rely on
these properties lose fidelity |
| Guardrails: 512 KB / 10k lines | Prevents pathological stalls on huge
diffs or pastes | Very large files render without color |
## Architecture
```
config.toml ─[tui.theme]─> set_theme_override() ─> THEME (RwLock)
│
┌───────────────────────────────────────────┘
│
markdown_render ─── highlight_code_to_lines(code, lang) ─> Vec<Line>
diff_render ─── highlight_code_to_styled_spans(code, lang) ─> Option<Vec<Vec<Span>>>
│
│ (None ⇒ plain text fallback)
│
/theme picker ─── set_syntax_theme(theme) // live preview swap
─── current_syntax_theme() // snapshot for cancel
─── resolve_theme_by_name(name) // lookup by kebab-case
```
Key files:
- `tui/src/render/highlight.rs` -- engine, theme management, guardrails
- `tui/src/diff_render.rs` -- syntax-aware diff line wrapping
- `tui/src/theme_picker.rs` -- `/theme` command builder
- `tui/src/bottom_pane/list_selection_view.rs` -- side content panel,
callbacks
- `core/src/config/types.rs` -- `Tui::theme` field
- `core/src/config/edit.rs` -- `syntax_theme_edit()` helper
## Observability
- `tracing::warn` when a configured theme name cannot be resolved.
- `Config::startup_warnings` surfaces the same message as a TUI banner.
- `tracing::error` when persisting theme selection fails.
## Tests
- Unit tests in `highlight.rs`: language coverage, fallback behavior,
CRLF stripping, style conversion, guardrail enforcement, theme name
mapping exhaustiveness.
- Unit tests in `diff_render.rs`: snapshot gallery at multiple terminal
sizes (80x24, 94x35, 120x40), syntax-highlighted wrapping, large-diff
guardrail, rename-to-different-extension highlighting, parser state
preservation across hunk lines.
- Unit tests in `theme_picker.rs`: preview rendering (wide + narrow),
dim overlay on deletions, subtitle truncation, cancel-restore, fallback
for unavailable configured theme.
- Unit tests in `list_selection_view.rs`: side layout geometry, stacked
fallback, buffer clearing, cancel/selection-changed callbacks.
- Integration test in `lib.rs`: theme warning uses the final
(post-resume) config.
## Cargo Deny: Unmaintained Dependency Exceptions
This PR adds two `cargo deny` advisory exceptions for transitive
dependencies pulled in by `syntect v5.3.0`:
| Advisory | Crate | Status |
|----------|-------|--------|
| RUSTSEC-2024-0320 | `yaml-rust` | Unmaintained (maintainer
unreachable) |
| RUSTSEC-2025-0141 | `bincode` | Unmaintained (development ceased;
v1.3.3 considered complete) |
**Why this is safe in our usage:**
- Neither advisory describes a known security vulnerability. Both are
"unmaintained" notices only.
- `bincode` is used by syntect to deserialize pre-compiled syntax sets.
Again, these are **static vendored artifacts** baked into the binary at
build time. No user-supplied bincode data is ever deserialized. - Attack
surface is zero for both crates; exploitation would require a
supply-chain compromise of our own build artifacts.
- These exceptions can be removed when syntect migrates to `yaml-rust2`
and drops `bincode`, or when alternative crates are available upstream.
## Why
`codex-rs/core/src/lib.rs` re-exported a broad set of types and modules
from `codex-protocol` and `codex-shell-command`. That made it easy for
workspace crates to import those APIs through `codex-core`, which in
turn hides dependency edges and makes it harder to reduce compile-time
coupling over time.
This change removes those public re-exports so call sites must import
from the source crates directly. Even when a crate still depends on
`codex-core` today, this makes dependency boundaries explicit and
unblocks future work to drop `codex-core` dependencies where possible.
## What Changed
- Removed public re-exports from `codex-rs/core/src/lib.rs` for:
- `codex_protocol::protocol` and related protocol/model types (including
`InitialHistory`)
- `codex_protocol::config_types` (`protocol_config_types`)
- `codex_shell_command::{bash, is_dangerous_command, is_safe_command,
parse_command, powershell}`
- Migrated workspace Rust call sites to import directly from:
- `codex_protocol::protocol`
- `codex_protocol::config_types`
- `codex_protocol::models`
- `codex_shell_command`
- Added explicit `Cargo.toml` dependencies (`codex-protocol` /
`codex-shell-command`) in crates that now import those crates directly.
- Kept `codex-core` internal modules compiling by using `pub(crate)`
aliases in `core/src/lib.rs` (internal-only, not part of the public
API).
- Updated the two utility crates that can already drop a `codex-core`
dependency edge entirely:
- `codex-utils-approval-presets`
- `codex-utils-cli`
## Verification
- `cargo test -p codex-utils-approval-presets`
- `cargo test -p codex-utils-cli`
- `cargo check --workspace --all-targets`
- `just clippy`
## Summary
- Adds a new `/statusline` command to configure TUI footer status line
- Introduces reusable `MultiSelectPicker` component with keyboard
navigation, optional ordering and toggle support
- Implement status line setup modal that persist configuration to
config.toml
## Status Line Items
The following items can be displayed in the status line:
- **Model**: Current model name (with optional reasoning level)
- **Context**: Remaining/used context window percentage
- **Rate Limits**: 5-day and weekly usage limits
- **Git**: Current branch (with optimized lookups)
- **Tokens**: Used tokens, input/output token counts
- **Session**: Session ID (full or shortened prefix)
- **Paths**: Current directory, project root
- **Version**: Codex version
## Features
- Live preview while configuring status line items
- Fuzzy search filtering in the picker
- Intelligent truncation when items don't fit
- Items gracefully omit when data is unavailable
- Configuration persists to `config.toml`
- Validates and warns about invalid status line items
## Test plan
- [x] Run `/statusline` and verify picker UI appears
- [x] Toggle items on/off and verify live preview updates
- [x] Confirm selection persists after restart
- [x] Verify truncation behavior with many items selected
- [x] Test git branch detection in and out of git repos
---------
Co-authored-by: Josh McKinney <joshka@openai.com>
I am trying to support building with [Buck2](https://buck2.build), which
reports which files have changed between invocations of `buck2 test` and
`tmp_delete_example.txt` came up. This turned out to be the reason.
- introduce RenderableItem to support both owned and borrowed children
in composite Renderables
- refactor some of our gnarlier manual layouts, BottomPane and
ChatWidget, to use ColumnRenderable
- Renderable and friends now handle cursor_pos()
Refactor trust_directory to use ColumnRenderable & friends, thus
correcting wrapping behavior at small widths. Also introduce
RowRenderable with fixed-width rows.
- fixed wrapping in trust_directory
- changed selector cursor to match other list item selections
- allow y/n to work as well as 1/2
- fixed key_hint to be standard
before:
<img width="661" height="550" alt="Screenshot 2025-10-09 at 9 50 36 AM"
src="https://github.com/user-attachments/assets/e01627aa-bee4-4e25-8eca-5575c43f05bf"
/>
after:
<img width="661" height="550" alt="Screenshot 2025-10-09 at 9 51 31 AM"
src="https://github.com/user-attachments/assets/cb816cbd-7609-4c83-b62f-b4dba392d79a"
/>
- prefix command approval reasons with "Reason:"
- show keyboard shortcuts for some ListSelectionItems
- remove "description" lines for approval options, and make the labels
more verbose
- add a spacer line in diff display after the path
and some other minor refactors that go along with the above.
<img width="859" height="508" alt="Screenshot 2025-10-02 at 1 24 50 PM"
src="https://github.com/user-attachments/assets/4fa7ecaf-3d3a-406a-bb4d-23e30ce3e5cf"
/>
Created this PR by:
- adding `redundant_clone` to `[workspace.lints.clippy]` in
`cargo-rs/Cargol.toml`
- running `cargo clippy --tests --fix`
- running `just fmt`
Though I had to clean up one instance of the following that resulted:
```rust
let codex = codex;
```
This PR:
* Added the clippy.toml to configure allowable expect / unwrap usage in
tests
* Removed as many expect/allow lines as possible from tests
* moved a bunch of allows to expects where possible
Note: in integration tests, non `#[test]` helper functions are not
covered by this so we had to leave a few lingering `expect(expect_used`
checks around
refactors HistoryCell to be a trait instead of an enum. Also collapse
the many "degenerate" HistoryCell enums which were just a store of lines
into a single PlainHistoryCell type.
The goal here is to allow more ways of rendering history cells (e.g.
expanded/collapsed/"live"), and I expect we will return to more varied
types of HistoryCell as we develop this area.
Felipe Coury ·
Michael Bolin ·
Josh McKinney ·
Jeremy Rose ·
jif-oai ·
Ahmed Ibrahim ·
Parker Thompson ·