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Codex CLI Integration Guide: APIpie Setup

APIpieOpenAI - Codex CLI

This guide will walk you through integrating OpenAI Codex CLI with APIpie, enabling advanced AI-powered coding, automation, and reasoning directly from your terminal.

What is Codex CLI?​

Codex CLI is a lightweight, open-source coding agent that runs in your terminal. It brings ChatGPT-level reasoning and automation to your development workflow, allowing you to:

  • Run code, manipulate files, and iterate under version control
  • Use multimodal input (text, screenshots, diagrams)
  • Operate in interactive or fully automated modes
  • Leverage advanced models for code, reasoning, and project automation

By connecting Codex CLI to APIpie, you unlock access to a wide range of powerful models, enhanced context windows, and cost-efficient AI capabilities.

Integration Steps​

1. Create an APIpie Account​

2. Add Credit​

3. Generate an API Key​

  • API Key Management: APIpie API Keys
  • Create a new API key for use with Codex CLI.

4. Install Codex CLI​

Install globally via npm:

npm install -g @openai/codex

Or with yarn:

yarn global add @openai/codex

5. Configure Codex CLI for APIpie​

Set your APIpie endpoint and API key as environment variables:

export OPENAI_BASE_URL="https://apipie.ai/v1"
export OPENAI_API_KEY="your-APIpie-key-here"
tip

Add these lines to your shell profile (e.g., ~/.zshrc, ~/.bashrc) for persistence.

You can now run Codex CLI with APIpie:

codex

Or with a prompt:

codex "explain this codebase to me"

6. (Optional) Advanced Configuration​

Codex CLI supports a config file at ~/.codex/config.yaml:

model: o4-mini # or any supported APIpie model [check out the dashboard](https://apipie.ai/dashboard)
fullAutoErrorMode: ask-user

You can also add custom instructions in ~/.codex/instructions.md.

OpenAI - Codex CLI

Key Features​

  • Zero Setup: Just set your APIpie API key and endpoint—no extra configuration required.
  • Full Auto-Approval: Use --approval-mode full-auto for hands-free automation (sandboxed and safe).
  • Multimodal Input: Pass screenshots or diagrams for multimodal reasoning.
  • Project Memory: Codex CLI merges project docs and instructions for context-aware automation.
  • Sandboxed Execution: All commands run network-disabled and directory-sandboxed for security.
  • Model Flexibility: Access APIpie's latest models (e.g., o3, o4-mini, GPT-4.1, Grok, Claude, Llama, etc.) for coding, reasoning, and more.

Example Workflows​

What you typeWhat happens
codex "Refactor the Dashboard component to React Hooks"Codex rewrites the component, runs tests, and shows the diff.
codex "Generate SQL migrations for adding a users table"Creates migration files and runs them in a sandboxed DB.
codex "Write unit tests for utils/date.ts"Generates and runs tests, iterating until they pass.
codex "Bulk-rename *.jpeg → *.jpg with git mv"Safely renames files and updates usages.
codex "Explain what this regex does: ^(?=.*[A-Z]).{8,}$"Outputs a step-by-step human explanation.
codex "Carefully review this repo, and propose 3 high impact PRs"Suggests impactful PRs in the current codebase.
codex "Look for vulnerabilities and create a security review report"Finds and explains security bugs.

Security & Permissions​

Codex CLI lets you control agent autonomy via the --approval-mode flag:

  • Suggest (default): Only reads files; all writes and shell commands require approval.
  • Auto Edit: Reads and writes files; shell commands require approval.
  • Full Auto: Reads/writes files and executes shell commands (all sandboxed).

All actions are sandboxed and network-disabled for safety.

Troubleshooting & FAQ​

  • Does Codex CLI work on Windows?
    Yes, via WSL2. Native support is available for macOS and Linux.
  • Which models are supported?
    Any model available via APIpie's OpenAI-compatible endpoint (e.g., o3, o4-mini, GPT-4.1, Grok, Claude, Llama, etc.)
  • How do I persist my API key and endpoint?
    Add the export lines to your shell profile.

For more, see the Codex CLI GitHub.

Support​

If you encounter any issues during the integration process, please reach out on APIpie Discord for assistance.