Codex CLI: Code-Focused AI Backend

The Codex CLI backend wraps OpenAI’s Codex CLI as a subprocess, providing code-focused agent capabilities with MCP support.

Overview

• Status: Beta
• Provider support: OpenAI
• Built-in tools: shell, file_edit, web_search, mcp
• MCP support: Yes
• Architecture: Subprocess wrapper — spawns the codex binary

Prerequisites

Install the Codex CLI globally:

npm install -g @openai/codex

Verify it’s on your PATH:

codex --version

Configuration

export POCKETPAW_AGENT_BACKEND="codex_cli"
export POCKETPAW_OPENAI_API_KEY="sk-..."

The backend also accepts CODEX_API_KEY as an alternative to OPENAI_API_KEY.

Backend-Specific Settings

Built-in Tools

How It Works

1. PocketPaw spawns the codex CLI binary as a subprocess
2. Messages and history are injected via the CLI’s input interface
3. Output streams as NDJSON (newline-delimited JSON)
4. PocketPaw parses NDJSON events into AgentEvent objects
5. MCP servers are forwarded to the Codex CLI

When to Use

Choose Codex CLI when:

• You want a code-focused agent optimized for programming tasks
• You’re already using OpenAI’s Codex CLI and want it integrated into PocketPaw
• You need MCP support with an OpenAI-based backend

Related