98923e53cc
## Problem The `ansi`, `base16`, and `base16-256` syntax themes are designed to emit ANSI palette colors so that highlighted code respects the user's terminal color scheme. Syntect encodes this intent in the alpha channel of its `Color` struct — a convention shared with `bat` — but `convert_style` was ignoring it entirely, treating every foreground color as raw RGB. This caused ANSI-family themes to produce hard-coded RGB values (e.g. `Rgb(0x02, 0, 0)` instead of `Green`), defeating their purpose and rendering them as near-invisible dark colors on most terminals. Reported in #12890. ## Mental model Syntect themes use a compact encoding in their `Color` struct: | `alpha` | Meaning of `r` | Mapped to | |---------|----------------|-----------| | `0x00` | ANSI palette index (0–255) | `RtColor::Black`…`Gray` for 0–7, `Indexed(n)` for 8–255 | | `0x01` | Unused (sentinel) | `None` — inherit terminal default fg/bg | | `0xFF` | True RGB red channel | `RtColor::Rgb(r, g, b)` | | other | Unexpected | `RtColor::Rgb(r, g, b)` (silent fallback) | This encoding is a bat convention that three bundled themes rely on. The new `convert_syntect_color` function decodes it; `ansi_palette_color` maps indices 0–7 to ratatui's named ANSI variants. | macOS - Dark | macOS - Light | Windows - ansi | Windows - base16 | |---|---|---|---| | <img width="1064" height="1205" alt="macos-dark" src="https://github.com/user-attachments/assets/f03d92fb-b44b-4939-b2b9-503fde133811" /> | <img width="1073" height="1227" alt="macos-light" src="https://github.com/user-attachments/assets/2ecb2089-73b5-4676-bed8-e4e6794250b4" /> |  |  | ## Non-goals - Background color decoding — we intentionally skip backgrounds to preserve the terminal's own background. The decoder supports it, but `convert_style` does not apply it. - Italic/underline changes — those remain suppressed as before. - Custom `.tmTheme` support for ANSI encoding — only the bundled themes use this convention. ## Tradeoffs - The alpha-channel encoding is an undocumented bat/syntect convention, not a formal spec. We match bat's behavior exactly, trading formality for ecosystem compatibility. - Indices 0–7 are mapped to ratatui's named variants (`Black`, `Red`, …, `Gray`) rather than `Indexed(0)`…`Indexed(7)`. This lets terminals apply bold/bright semantics to named colors, which is the expected behavior for ANSI themes, but means the two representations are not perfectly round-trippable. ## Architecture All changes are in `codex-rs/tui/src/render/highlight.rs`, within the style-conversion layer between syntect and ratatui: ``` syntect::highlighting::Color └─ convert_syntect_color(color) [NEW — alpha-dispatch] ├─ a=0x00 → ansi_palette_color() [NEW — index→named/indexed] ├─ a=0x01 → None (terminal default) ├─ a=0xFF → Rgb(r,g,b) (standard opaque path) └─ other → Rgb(r,g,b) (silent fallback) ``` `convert_style` delegates foreground mapping to `convert_syntect_color` instead of inlining the `Rgb(r,g,b)` conversion. The core highlighter is refactored into `highlight_to_line_spans_with_theme` (accepts an explicit theme reference) so tests can highlight against specific themes without mutating process-global state. ### ANSI-family theme contract The ANSI-family themes (`ansi`, `base16`, `base16-256`) rely on upstream alpha-channel encoding from two_face/syntect. We intentionally do **not** validate this contract at runtime — if the upstream format changes, the `ansi_themes_use_only_ansi_palette_colors` test catches it at build time, long before it reaches users. A runtime warning would be unactionable noise. ### Warning copy cleanup User-facing warning messages were rewritten for clarity: - Removed internal jargon ("alpha-encoded ANSI color markers", "RGB fallback semantics", "persisted override config") - Dropped "syntax" prefix from "syntax theme" — users just think "theme" - Downgraded developer-only diagnostics (duplicate override, resolve fallback) from `warn` to `debug` ## Observability - The `ansi_themes_use_only_ansi_palette_colors` test enforces the ANSI-family contract at build time. - The snapshot test provides a regression tripwire for palette color output. - User-facing warnings are limited to actionable issues: unknown theme names and invalid custom `.tmTheme` files. ## Tests - **Unit tests for each alpha branch:** `alpha=0x00` with low index (named color), `alpha=0x00` with high index (`Indexed`), `alpha=0x01` (terminal default), unexpected alpha (falls back to RGB), ANSI white → Gray mapping. - **Integration test:** `ansi_family_themes_use_terminal_palette_colors_not_rgb` — highlights a Rust snippet with each ANSI-family theme and asserts zero `Rgb` foreground colors appear. - **Snapshot test:** `ansi_family_foreground_palette_snapshot` — records the exact set of unique foreground colors each ANSI-family theme produces, guarding against regressions. - **Warning validation tests:** verify user-facing warnings for missing custom themes, invalid `.tmTheme` files, and bundled theme resolution. ## Test plan - [ ] `cargo test -p codex-tui` passes all new and existing tests - [ ] Select `ansi`, `base16`, or `base16-256` theme and verify code blocks render with terminal palette colors (not near-black RGB) - [ ] Select a standard RGB theme (e.g. `dracula`) and verify no regression in color output |
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| .. | ||
| .cargo | ||
| .config | ||
| .github/workflows | ||
| ansi-escape | ||
| app-server | ||
| app-server-protocol | ||
| app-server-test-client | ||
| apply-patch | ||
| arg0 | ||
| artifact-presentation | ||
| artifact-spreadsheet | ||
| 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 | ||
| test-macros | ||
| 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".
In workspace-write, Codex also includes ~/.codex/memories in its writable roots so memory maintenance does not require an extra approval.
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.