Codex

Codex is an AI coding agent from OpenAI that helps you write, review, and debug code. It is available both as a terminal tool and a desktop application.

Codex requires a dedicated OpenAI Responses protocol endpoint: https://api.z.ai/api/v1.

Step 1: Install Codex

Codex is available in two forms: the Codex CLI that runs in your terminal, and the desktop Codex app. Choose whichever fits your workflow.

Install the Codex App
Install Codex CLI

Visit the ChatGPT download page and download the installer for your operating system.
Follow the system prompts to complete the installation and launch the app.
If you already have Codex CLI installed, you can also launch the desktop app directly from the terminal:
codex app

Prerequisites:

Node.js 18 or newer
macOS users are recommended to install Node.js via nvm. Direct package installation is not recommended (it may cause permission issues later).

Open a terminal and install Codex CLI:

npm install -g @openai/codex

Run the following command to verify the installation. A version number indicates success:

codex --version

Step 2: Configure GLM Coding Plan

Visit the Z.AI Open Platform, click the “Register/Login” button in the top right, and follow the prompts to complete the registration process.

Get Your API Key

Individual Plan users can create an API Key under Individual Coding Plan > Plan Overview.
Team Plan members can obtain their API Key under Team Coding Plan > My Plan. The Team Plan Key is not interchangeable with other Z.AI API Keys. To use your Team Plan quota, make sure to use the Team Plan Key.

Keep your API Key safe. Do not share it with others or hard-code it directly in your code.

Configure the Model and API Key

Codex connects via the OpenAI Responses protocol, using the endpoint https://api.z.ai/api/v1.

Choose whichever configuration method below suits you.

Manual Configuration

Supported on macOS & Linux & Windows. Note that config file paths differ by system. Make sure the file format is correct after editing.

1. Create the Model Catalog File

Create ~/.codex/models.json to declare GLM model metadata to Codex. If the file or directory does not exist, create it first.Copy the following content entirely into ~/.codex/models.json:

{
    "models": [
        {
            "slug": "glm-5.3",
            "display_name": "glm-5.3",
            "description": "Z.ai's latest flagship model",
            "default_reasoning_level": "max",
            "supported_reasoning_levels": [
                {
                    "effort": "low",
                    "description": "Light reasoning"
                },
                {
                    "effort": "high",
                    "description": "Enhanced reasoning"
                },
                {
                    "effort": "max",
                    "description": "Deep reasoning"
                }
            ],
            "shell_type": "shell_command",
            "visibility": "list",
            "supported_in_api": true,
            "priority": 0,
            "base_instructions": "",
            "supports_reasoning_summaries": true,
            "default_reasoning_summary": "none",
            "support_verbosity": false,
            "apply_patch_tool_type": "freeform",
            "truncation_policy": {
                "mode": "bytes",
                "limit": 10000
            },
            "context_window": 1048576,
            "max_context_window": 1048576,
            "effective_context_window_percent": 95,
            "supports_parallel_tool_calls": true,
            "experimental_supported_tools": [],
            "input_modalities": [
                "text"
            ]
        },
        {
            "slug": "glm-5-turbo",
            "display_name": "glm-5-turbo",
            "description": "Agent-optimized model",
            "default_reasoning_level": "max",
            "supported_reasoning_levels": [],
            "shell_type": "shell_command",
            "visibility": "list",
            "supported_in_api": true,
            "priority": 1,
            "base_instructions": "",
            "supports_reasoning_summaries": true,
            "default_reasoning_summary": "none",
            "support_verbosity": false,
            "apply_patch_tool_type": "freeform",
            "truncation_policy": {
                "mode": "bytes",
                "limit": 10000
            },
            "context_window": 204800,
            "max_context_window": 204800,
            "effective_context_window_percent": 95,
            "supports_parallel_tool_calls": true,
            "experimental_supported_tools": [],
            "input_modalities": [
                "text"
            ]
        }
    ]
}

2. Configure the API Key and Model

Locate the Codex configuration file at the following path. Create it if it does not exist:

macOS/Linux: ~/.codex/config.toml
Windows: C:\Users\<YourUsername>\.codex\config.toml

Copy the following content entirely into ~/.codex/config.toml, replacing <Your API Key> with the API Key you obtained in the previous step:

model_provider = "ZAI"
model = "glm-5.3"
model_reasoning_effort = "max"
model_catalog_json = "~/.codex/models.json"

[model_providers.ZAI]
name = "ZAI"
base_url = "https://api.z.ai/api/v1"
experimental_bearer_token = "<Your API Key>"
wire_api = "responses"

wire_api must be set to responses.
model_catalog_json points to the model metadata file created in the previous step.
model can be switched to glm-5.3 or any other model declared in models.json as needed.

After a successful configuration, restart the app for the changes to take effect.

Step 3: Start Using Codex

Once configured, restart your Codex app or open a new terminal and run the codex command to get started.

Step 4: FAQ

Manual Configuration Not Taking Effect

Close all Codex windows, open a new terminal window, and run codex again to start.
Confirm that ~/.codex/models.json exists and is valid JSON. You can use an online JSON validator to check.
Confirm that the model_catalog_json path in ~/.codex/config.toml is correct.
Confirm that experimental_bearer_token has been replaced with your actual API Key.
Confirm that the TOML format of the configuration file is correct—check field names, quotes, and brackets for completeness.

GLM Coding Plan

Guide

Notice

Learning Resources

Campaign Rules

Step 1: Install Codex

Step 2: Configure GLM Coding Plan

1. Create the Model Catalog File

2. Configure the API Key and Model

Step 3: Start Using Codex

Step 4: FAQ

Manual Configuration Not Taking Effect

​Step 1: Install Codex

​Step 2: Configure GLM Coding Plan

​1. Create the Model Catalog File

​2. Configure the API Key and Model

​Step 3: Start Using Codex

​Step 4: FAQ

​Manual Configuration Not Taking Effect

Step 1: Install Codex

Step 2: Configure GLM Coding Plan

1. Create the Model Catalog File

2. Configure the API Key and Model

Step 3: Start Using Codex

Step 4: FAQ

Manual Configuration Not Taking Effect