> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/openai/codex/llms.txt
> Use this file to discover all available pages before exploring further.

# codex fork

> Fork a previous interactive session to explore alternative approaches

The `fork` command creates a new session based on an existing one, allowing you to explore different approaches while preserving the original conversation.

## Usage

```bash theme={null}
codex fork              # Shows picker to select session to fork
codex fork --last       # Fork most recent session
```

## Description

Forking creates a copy of a previous session's history and starts a new interactive session from that point. This is useful when you want to:

* Try a different approach to solving a problem
* Explore alternative implementations
* Experiment without affecting the original session
* Branch off from a specific point in a conversation

The fork creates a new thread ID with the copied history, leaving the original session unchanged.

## Options

<ParamField path="--last" type="boolean">
  Fork the most recent session without showing the picker.
</ParamField>

## Examples

### Interactive Picker

Show a picker to select which session to fork:

```bash theme={null}
codex fork
```

### Fork Latest

Automatically fork your most recent session:

```bash theme={null}
codex fork --last
```

## How It Works

1. Codex loads the selected session's history
2. Creates a new thread ID
3. Copies all conversation history to the new thread
4. Opens the interactive TUI with the forked session
5. You can now continue in a different direction

## Use Cases

* **A/B testing approaches**: Try two different solutions to the same problem
* **Experimentation**: Test ideas without losing your original work
* **Decision points**: Fork when you reach a critical architectural choice
* **Learning**: Explore "what if" scenarios with the same context

## Comparison: Fork vs Resume

| Feature          | Fork             | Resume        |
| ---------------- | ---------------- | ------------- |
| Original session | Unchanged        | Continued     |
| New thread ID    | Yes              | No            |
| History          | Copied           | Shared        |
| Use case         | Try alternatives | Continue work |

## Related Commands

<CardGroup cols={2}>
  <Card title="codex resume" href="/cli/resume">
    Resume an existing session
  </Card>

  <Card title="codex" href="/cli/codex">
    Start a new interactive session
  </Card>
</CardGroup>