Agent IDE — Codex fork for AI-native development environment
2651980bdf
Enterprises want to restrict the MCP servers their users can use.
Admins can now specify an allowlist of MCPs in `requirements.toml`. The
MCP servers are matched on both Name and Transport (local path or HTTP
URL) -- both must match to allow the MCP server. This prevents
circumventing the allowlist by renaming MCP servers in user config. (It
is still possible to replace the local path e.g. rewrite say
`/usr/local/github-mcp` with a nefarious MCP. We could allow hash
pinning in the future, but that would break updates. I also think this
represents a broader, out-of-scope problem.)
We introduce a new field to Constrained: "normalizer". In general, it is
a fn(T) -> T and applies when `Constrained<T>.set()` is called. In this
particular case, it disables MCP servers which do not match the
allowlist. An alternative solution would remove this and instead throw a
ConstraintError. That would stop Codex launching if any MCP server was
configured which didn't match. I think this is bad.
We currently reuse the enabled flag on MCP servers to disable them, but
don't propagate any information about why they are disabled. I'd like to
add that in a follow up PR, possibly by switching out enabled with an
enum.
In action:
```
# MCP server config has two MCPs. We are going to allowlist one of them.
➜ codex git:(gt/restrict-mcps) ✗ cat ~/.codex/config.toml | grep mcp_servers -A1
[mcp_servers.hello_world]
command = "hello-world-mcp"
--
[mcp_servers.docs]
command = "docs-mcp"
# Restrict the MCPs to the hello_world MCP.
➜ codex git:(gt/restrict-mcps) ✗ defaults read com.openai.codex requirements_toml_base64 | base64 -d
[mcp_server_allowlist.hello_world]
command = "hello-world-mcp"
# List the MCPs, observe hello_world is enabled and docs is disabled.
➜ codex git:(gt/restrict-mcps) ✗ just codex mcp list
cargo run --bin codex -- "$@"
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.25s
Running `target/debug/codex mcp list`
Name Command Args Env Cwd Status Auth
docs docs-mcp - - - disabled Unsupported
hello_world hello-world-mcp - - - enabled Unsupported
# Remove the restrictions.
➜ codex git:(gt/restrict-mcps) ✗ defaults delete com.openai.codex requirements_toml_base64
# Observe both MCPs are enabled.
➜ codex git:(gt/restrict-mcps) ✗ just codex mcp list
cargo run --bin codex -- "$@"
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.25s
Running `target/debug/codex mcp list`
Name Command Args Env Cwd Status Auth
docs docs-mcp - - - enabled Unsupported
hello_world hello-world-mcp - - - enabled Unsupported
# A new requirements that updates the command to one that does not match.
➜ codex git:(gt/restrict-mcps) ✗ cat ~/requirements.toml
[mcp_server_allowlist.hello_world]
command = "hello-world-mcp-v2"
# Use those requirements.
➜ codex git:(gt/restrict-mcps) ✗ defaults write com.openai.codex requirements_toml_base64 "$(base64 -i /Users/gt/requirements.toml)"
# Observe both MCPs are disabled.
➜ codex git:(gt/restrict-mcps) ✗ just codex mcp list
cargo run --bin codex -- "$@"
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.75s
Running `target/debug/codex mcp list`
Name Command Args Env Cwd Status Auth
docs docs-mcp - - - disabled Unsupported
hello_world hello-world-mcp - - - disabled Unsupported
```
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|---|---|---|
| .devcontainer | ||
| .github | ||
| .vscode | ||
| codex-cli | ||
| codex-rs | ||
| docs | ||
| patches | ||
| scripts | ||
| sdk/typescript | ||
| shell-tool-mcp | ||
| third_party/wezterm | ||
| .bazelignore | ||
| .bazelrc | ||
| .codespellignore | ||
| .codespellrc | ||
| .gitignore | ||
| .npmrc | ||
| .prettierignore | ||
| .prettierrc.toml | ||
| AGENTS.md | ||
| announcement_tip.toml | ||
| BUILD.bazel | ||
| CHANGELOG.md | ||
| cliff.toml | ||
| defs.bzl | ||
| flake.lock | ||
| flake.nix | ||
| justfile | ||
| LICENSE | ||
| MODULE.bazel | ||
| MODULE.bazel.lock | ||
| NOTICE | ||
| package.json | ||
| pnpm-lock.yaml | ||
| pnpm-workspace.yaml | ||
| PNPM.md | ||
| rbe.bzl | ||
| README.md | ||
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 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.