Configure OpenAI Codex CLI with the KiosAPI Gateway

Configure OpenAI’s Codex CLI coding agent to use KiosAPI as the backend, connecting it to KiosAPI’s unified OpenAI-compatible API gateway.

OpenAI’s Codex CLI is a command-line coding agent that lets you interact with AI models directly from your terminal. This tutorial walks you through installing Codex CLI, creating a KiosAPI provider profile, and verifying that requests are routed correctly through KiosAPI.

System Requirements

Requirement	Minimum	Recommended
Operating System	macOS 12+, Ubuntu 20.04+, or Windows 11 (WSL2)	—
RAM	4 GB	8 GB
Node.js	22+	Latest LTS
Disk Space	200 MB	500 MB

You also need a KiosAPI API key (starts with sk-) from the Dashboard → Token Management.

Usage

Interactive mode

codex

VSCode Plugin

Codex is also available as a VSCode extension. After installing the extension, configure it to use KiosAPI by setting the same environment variables in your VSCode settings or terminal.

The VSCode extension reads environment variables from your shell. Make sure KILOAPI_KEY is exported in the shell that launches VSCode, or set it in the integrated terminal.

Advanced Configuration

Non-interactive CI mode

For CI/CD pipelines, run Codex in non-interactive mode:

codex --quiet --auto-approve "Fix the failing test in tests/auth.test.js"

Flag	Description
--quiet	Suppress interactive prompts
--auto-approve	Automatically approve file changes
--json	Output results as JSON

MCP servers

Codex supports Model Context Protocol (MCP) servers for extended tool access. Add MCP servers to ~/.codex/config.toml:

[mcp.filesystem]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/dir"]

[mcp.github]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-github"]
env = { GITHUB_PERSONAL_ACCESS_TOKEN = "ghp_xxx" }

Troubleshooting

Authentication error (401)

• Verify KILOAPI_KEY is set correctly: echo $KILOAPI_KEY
• Ensure the key starts with sk-
• Check that the env_key value in your config file matches the environment variable name exactly

Model not found

• Verify the model name in your profile is correct
• Check available models on the KiosAPI pricing page

Connection error

• Ensure base_url is https://kiosapi.com/v1 (with /v1)
• Check your network connection and firewall settings

Need Help?

• KiosAPI Dashboard
• Token Management Guide
• Available Models