061d1d3b5e
## 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. |
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| .. | ||
| .cargo | ||
| .config | ||
| .github/workflows | ||
| ansi-escape | ||
| app-server | ||
| app-server-protocol | ||
| app-server-test-client | ||
| apply-patch | ||
| arg0 | ||
| async-utils | ||
| backend-client | ||
| chatgpt | ||
| cli | ||
| cloud-requirements | ||
| cloud-tasks | ||
| cloud-tasks-client | ||
| codex-api | ||
| codex-backend-openapi-models | ||
| codex-client | ||
| codex-experimental-api-macros | ||
| config | ||
| core | ||
| debug-client | ||
| docs | ||
| exec | ||
| execpolicy | ||
| execpolicy-legacy | ||
| feedback | ||
| file-search | ||
| hooks | ||
| keyring-store | ||
| linux-sandbox | ||
| lmstudio | ||
| login | ||
| mcp-server | ||
| network-proxy | ||
| ollama | ||
| otel | ||
| process-hardening | ||
| protocol | ||
| responses-api-proxy | ||
| rmcp-client | ||
| scripts | ||
| secrets | ||
| shell-command | ||
| shell-escalation | ||
| skills | ||
| state | ||
| stdio-to-uds | ||
| tui | ||
| utils | ||
| vendor | ||
| windows-sandbox-rs | ||
| .gitignore | ||
| BUILD.bazel | ||
| Cargo.lock | ||
| Cargo.toml | ||
| clippy.toml | ||
| config.md | ||
| default.nix | ||
| deny.toml | ||
| node-version.txt | ||
| README.md | ||
| rust-toolchain.toml | ||
| rustfmt.toml | ||
Codex CLI (Rust Implementation)
We provide Codex CLI as a standalone, native executable to ensure a zero-dependency install.
Installing Codex
Today, the easiest way to install Codex is via npm:
npm i -g @openai/codex
codex
You can also install via Homebrew (brew install --cask codex) or download a platform-specific release directly from our GitHub Releases.
Documentation quickstart
- First run with Codex? Start with
docs/getting-started.md(links to the walkthrough for prompts, keyboard shortcuts, and session management). - Want deeper control? See
docs/config.mdanddocs/install.md.
What's new in the Rust CLI
The Rust implementation is now the maintained Codex CLI and serves as the default experience. It includes a number of features that the legacy TypeScript CLI never supported.
Config
Codex supports a rich set of configuration options. Note that the Rust CLI uses config.toml instead of config.json. See docs/config.md for details.
Model Context Protocol Support
MCP client
Codex CLI functions as an MCP client that allows the Codex CLI and IDE extension to connect to MCP servers on startup. See the configuration documentation for details.
MCP server (experimental)
Codex can be launched as an MCP server by running codex mcp-server. This allows other MCP clients to use Codex as a tool for another agent.
Use the @modelcontextprotocol/inspector to try it out:
npx @modelcontextprotocol/inspector codex mcp-server
Use codex mcp to add/list/get/remove MCP server launchers defined in config.toml, and codex mcp-server to run the MCP server directly.
Notifications
You can enable notifications by configuring a script that is run whenever the agent finishes a turn. The notify documentation includes a detailed example that explains how to get desktop notifications via terminal-notifier on macOS. When Codex detects that it is running under WSL 2 inside Windows Terminal (WT_SESSION is set), the TUI automatically falls back to native Windows toast notifications so approval prompts and completed turns surface even though Windows Terminal does not implement OSC 9.
codex exec to run Codex programmatically/non-interactively
To run Codex non-interactively, run codex exec PROMPT (you can also pass the prompt via stdin) and Codex will work on your task until it decides that it is done and exits. Output is printed to the terminal directly. You can set the RUST_LOG environment variable to see more about what's going on.
Use codex exec --ephemeral ... to run without persisting session rollout files to disk.
Experimenting with the Codex Sandbox
To test to see what happens when a command is run under the sandbox provided by Codex, we provide the following subcommands in Codex CLI:
# macOS
codex sandbox macos [--full-auto] [--log-denials] [COMMAND]...
# Linux
codex sandbox linux [--full-auto] [COMMAND]...
# Windows
codex sandbox windows [--full-auto] [COMMAND]...
# Legacy aliases
codex debug seatbelt [--full-auto] [--log-denials] [COMMAND]...
codex debug landlock [--full-auto] [COMMAND]...
Selecting a sandbox policy via --sandbox
The Rust CLI exposes a dedicated --sandbox (-s) flag that lets you pick the sandbox policy without having to reach for the generic -c/--config option:
# Run Codex with the default, read-only sandbox
codex --sandbox read-only
# Allow the agent to write within the current workspace while still blocking network access
codex --sandbox workspace-write
# Danger! Disable sandboxing entirely (only do this if you are already running in a container or other isolated env)
codex --sandbox danger-full-access
The same setting can be persisted in ~/.codex/config.toml via the top-level sandbox_mode = "MODE" key, e.g. sandbox_mode = "workspace-write".
Code Organization
This folder is the root of a Cargo workspace. It contains quite a bit of experimental code, but here are the key crates:
core/contains the business logic for Codex. Ultimately, we hope this to be a library crate that is generally useful for building other Rust/native applications that use Codex.exec/"headless" CLI for use in automation.tui/CLI that launches a fullscreen TUI built with Ratatui.cli/CLI multitool that provides the aforementioned CLIs via subcommands.
If you want to contribute or inspect behavior in detail, start by reading the module-level README.md files under each crate and run the project workspace from the top-level codex-rs directory so shared config, features, and build scripts stay aligned.