## Why Once multi-agent mode can be selected per turn, clients also need to choose the initial selection when creating a thread and observe that selection through lifecycle and settings APIs. The selected value is intentionally distinct from the effective model-visible value: no client selection is represented as `null`, even though an eligible multi-agent v2 turn derives `explicitRequestOnly` as its effective default. ## What changed - Add the optional experimental `thread/start.multiAgentMode` parameter and pass it through thread creation. - Preserve an omitted initial value as an unset selection rather than eagerly storing `explicitRequestOnly`. - Apply an explicit `thread/start` selection to the first turn through the session configuration established at thread creation. - Restore the latest persisted effective mode as the selected baseline on cold resume when rollout history contains one. - Inherit the optional selected mode from a loaded parent when creating related runtime threads. - Return the current selected `multiAgentMode` from `thread/start`, `thread/resume`, `thread/fork`, and thread settings, using `null` when no mode is selected. - Keep lifecycle reporting independent from model capability and feature eligibility; core turn construction remains responsible for calculating and persisting the effective mode. ## Not covered - Clearing an existing loaded-session selection back to unset through `turn/start`; omitted or `null` currently retains the session's selection. - A TUI control, slash command, or `config.toml` preference. ## Verification - `CARGO_INCREMENTAL=0 just test -p codex-app-server-protocol` - `CARGO_INCREMENTAL=0 just test -p codex-app-server multi_agent_mode` The focused app-server coverage verifies explicit `thread/start` initialization, first-turn prompting, nullable reporting for an omitted selection, and retention of selections that are not currently runtime-eligible. ## Stack Stacked on #28685. This PR contains only the thread initialization and lifecycle/settings API layer.
Codex CLI is a coding agent from OpenAI that runs locally on your computer.
If you want Codex in your code editor (VS Code, Cursor, Windsurf), install in your IDE.
If you want the desktop app experience, run
codex app or visit the Codex App page.
If you are looking for the cloud-based agent from OpenAI, Codex Web, go to chatgpt.com/codex.
Quickstart
Installing and running Codex CLI
Run the following on Mac or Linux to install Codex CLI:
curl -fsSL https://chatgpt.com/codex/install.sh | sh
Run the following on Windows to install Codex CLI:
powershell -ExecutionPolicy ByPass -c "irm https://chatgpt.com/codex/install.ps1 | iex"
Codex CLI can also be installed via the following package managers:
# Install using npm
npm install -g @openai/codex
# Install using Homebrew
brew install --cask codex
Then simply run codex to get started.
You can also go to the latest GitHub Release and download the appropriate binary for your platform.
Each GitHub Release contains many executables, but in practice, you likely want one of these:
- macOS
- Apple Silicon/arm64:
codex-aarch64-apple-darwin.tar.gz - x86_64 (older Mac hardware):
codex-x86_64-apple-darwin.tar.gz
- Apple Silicon/arm64:
- Linux
- x86_64:
codex-x86_64-unknown-linux-musl.tar.gz - arm64:
codex-aarch64-unknown-linux-musl.tar.gz
- x86_64:
Each archive contains a single entry with the platform baked into the name (e.g., codex-x86_64-unknown-linux-musl), so you likely want to rename it to codex after extracting it.
Using Codex with your ChatGPT plan
Run codex and select Sign in with ChatGPT. We recommend signing into your ChatGPT account to use Codex as part of your Plus, Pro, Business, Edu, or Enterprise plan. Learn more about what's included in your ChatGPT plan.
You can also use Codex with an API key, but this requires additional setup.
Docs
This repository is licensed under the Apache-2.0 License.
