---
title: OpenAI Codex
description: Run OpenAI's Codex CLI against any Mirage workspace by mounting it as a real filesystem via FUSE.
icon: /images/openai-logo.svg
---

[OpenAI Codex](https://github.com/openai/codex) is OpenAI's coding-agent CLI. Like [Claude Code](/python/agents/claude-code), it operates on a real filesystem and doesn't expose a pluggable backend, so Mirage integrates by [FUSE-mounting](/python/setup/fuse) a workspace and letting you point `codex` at the mountpoint.

## Install

```bash
uv add 'mirage-ai[fuse]'
```

Then install [OpenAI Codex](https://github.com/openai/codex) separately.

## Usage

```python
from mirage import Mount, MountMode, Workspace
from mirage.resource.ram import RAMResource

with Workspace(
    {"/": Mount(RAMResource(), mode=MountMode.WRITE, fuse=True)}) as ws:
    print(f"cd {ws.fuse_mountpoint} && codex")
    input("Press Enter when done...")
```

The mountpoint behaves like a regular directory. Codex's `read_file`, `write_file`, and `run_shell` tools all dispatch through Mirage's ops layer.

## Why FUSE instead of an SDK integration?

The Codex CLI's tool surface isn't pluggable, it expects host file operations. FUSE makes those host operations *be* Mirage operations.

You lose per-tool customization and Mirage's op-record telemetry; you gain zero integration effort and compatibility with every Codex feature. Same trade-off as [Claude Code](/python/agents/claude-code).