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

# Codex

[Codex](https://openai.com/codex) is OpenAI's AI-powered coding agent. It reads custom instructions from `AGENTS.md` before doing any work, so you can give it project-specific guidance. With Bruno's local-first approach, you can add an `AGENTS.md` at your project root so Codex understands how to generate and work with Bruno collections.

<Info>
  Codex discovers instructions in this order: global `~/.codex/AGENTS.md`, See [Custom instructions with AGENTS.md](https://developers.openai.com/codex/guides/agents-md/) for full details.
</Info>

## Configure Codex with Bruno

1. Install and set up Codex from the [Codex documentation](https://developers.openai.com/codex/).

2. At your project root (typically the Git root), create an `AGENTS.md` file with instructions for working with Bruno collections.

Your project folder structure should look like this:

<Tree>
  <Tree.Folder name="my-project" defaultOpen>
    <Tree.Folder name="codex" defaultOpen>
      <Tree.File name="AGENTS.md" />
    </Tree.Folder>

    <Tree.Folder name="src" defaultOpen>
      <Tree.Folder name="routes">
        <Tree.File name="users.js" />

        <Tree.File name="auth.js" />
      </Tree.Folder>

      <Tree.File name="app.js" />

      <Tree.File name="server.js" />
    </Tree.Folder>

    <Tree.Folder name="bruno-collection">
      <Tree.File name="bruno.json" />
    </Tree.Folder>

    <Tree.File name="package.json" />

    <Tree.File name=".gitignore" />
  </Tree.Folder>
</Tree>

<Warning>
  You can write your own instructions in `AGENTS.md` for Codex to follow when working on Bruno collections, or use the [default instructions provided by Bruno](https://github.com/bruno-collections/ai-assistant-prompts) if available for Codex.
</Warning>

For example workflows and prompts, see [Use cases](./use-cases).