28bfbb8f2b
Currently there is no bound on the length of a user message submitted in the TUI or through the app server interface. That means users can paste many megabytes of text, which can lead to bad performance, hangs, and crashes. In extreme cases, it can lead to a [kernel panic](https://github.com/openai/codex/issues/12323). This PR limits the length of a user input to 2**20 (about 1M) characters. This value was chosen because it fills the entire context window on the latest models, so accepting longer inputs wouldn't make sense anyway. Summary - add a shared `MAX_USER_INPUT_TEXT_CHARS` constant in codex-protocol and surface it in TUI and app server code - block oversized submissions in the TUI submit flow and emit error history cells when validation fails - reject heavy app-server requests with JSON-RPC `-32602` and structured `input_too_large` data, plus document the behavior Testing - ran the IDE extension with this change and verified that when I attempt to paste a user message that's several MB long, it correctly reports an error instead of crashing or making my computer hot.
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.