## Why Codex Apps tools can mark arguments with `openai/fileParams`, but the execution path resolved and opened those files directly on the host. That bypassed the selected turn environment and prevented annotated file arguments from working with remote environments. ## What changed - resolve annotated file arguments against the primary turn environment - read file metadata and contents through that environment's sandboxed `ExecutorFileSystem` - reject files over the 512 MiB limit from metadata before reading or transferring them - retain the buffered upload-size check as defense in depth - make the OpenAI upload API accept a filename and buffered contents instead of owning local filesystem access - describe the model-visible argument as a path in the primary environment This builds on #27927, which added `size` to internal filesystem metadata. ## Testing - `just test -p codex-api upload_openai_file_returns_canonical_uri` - `just test -p codex-mcp tool_with_model_visible_input_schema_masks_file_params` - `just test -p codex-core mcp_openai_file` - `just test -p codex-core codex_apps_file_params_upload_environment_files_before_mcp_tool_call`
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.
