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Overview

OpenAI Codex is a code-specialized agent from OpenAI. When configured in Zenflow, it runs inside isolated Git worktrees with access to Zencoder’s context engine, multi-repo search, and Zen Rules.

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Setup

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Prerequisites

You need one of:

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Installation

1

Install Codex CLI

Install the OpenAI Codex agent on your machine. See OpenAI’s documentation for installation instructions.
2

Configure API key

Set your OpenAI API key during the authentication flow.
3

Select in Zenflow

In Zenflow, go to Settings → Saved presets and select Codex as the agent for your tasks.

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When to Use Codex

  • Code generation: Fast, accurate code writing across many languages
  • Test generation: Comprehensive test suites from existing code
  • Quick iterations: Fast response times for rapid prototyping
  • API integration: Strong understanding of APIs and SDKs

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Configurations

  • Sandbox – Controls what Codex can do without asking: None, Always ask, Workspace write, or Danger full access.
  • Model – Override the Codex model ID.
  • Model reasoning effort – Controls how much compute Codex spends reasoning: none, low, medium, high.

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Pricing

OptionHow It Works
BYOK (API Key)Pay OpenAI directly based on token usage

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Next Steps

Supported Agents

Compare all available agents

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Try Claude for reasoning tasks