f5bb338fdb
## Summary - defer fresh-session `build_initial_context()` until the first real turn instead of seeding model-visible context during startup - rely on the existing `reference_context_item == None` turn-start path to inject full initial context on that first real turn (and again after baseline resets such as compaction) - add a regression test for `InitialHistory::New` and update affected deterministic tests / snapshots around developer-message layout, collaboration instructions, personality updates, and compact request shapes ## Notes - this PR does not add any special empty-thread `/compact` behavior - most of the snapshot churn is the direct result of moving the initial model-visible context from startup to the first real turn, so first-turn request layouts no longer contain a pre-user startup copy of permissions / environment / other developer-visible context - remote manual `/compact` with no prior user still skips the remote compact request; local first-turn `/compact` still issues a compact request, but that request now reflects the lack of startup-seeded context --------- Co-authored-by: Codex <noreply@openai.com>
npm i -g @openai/codex
or brew install --cask codex
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
Install globally with your preferred package manager:
# 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, Team, 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.