Codex Setup Guide

Install and configure Codex CLI, and connect to the Coding Flow platform via configuration files.

Codex is a CLI tool that supports OpenAI-compatible APIs and is configured via files. This guide walks you through installation and configuration.

Before you start, complete the Node.js installation guide.

Prerequisites

• A valid API Key (e.g. sk-******)
• An accessible service address (Base URL) (usually provided by your deployment/gateway)

Common service Endpoint for This Site

• https://api.codingflow.ai

Step 1: Install Codex

Run the following command to download and install the latest version of Codex from the npm registry.

Windows

npm install -g @openai/codex@latest

Linux

sudo npm install -g @openai/codex@latest

macOS

sudo npm install -g @openai/codex@latest

Verify installation

After installation, run the command below. If it prints a version number, the installation succeeded.

codex --version

Step 2: Create the configuration files

Codex uses configuration files for connection setup. You need to create two files: config.toml and auth.json.

Create the configuration directory

Windows

# Remove the old directory and create a new one
if (Test-Path "$env:USERPROFILE\.codex") { Remove-Item -Recurse -Force "$env:USERPROFILE\.codex" }
mkdir "$env:USERPROFILE\.codex"

Linux

# Remove the old directory and create a new one
rm -rf ~/.codex && mkdir -p ~/.codex

macOS

# Remove the old directory and create a new one
rm -rf ~/.codex && mkdir -p ~/.codex

Create the configuration files

Windows

# Create config.toml
@"
model_provider = "codingflow"
model = "gpt-5.4"
model_reasoning_effort = "high"
disable_response_storage = true
preferred_auth_method = "apikey"

[model_providers.codingflow]
name = "codingflow"
base_url = "https://api.codingflow.ai/v1"
wire_api = "responses"
requires_openai_auth = true
"@ | Out-File -FilePath "$env:USERPROFILE\.codex\config.toml" -Encoding utf8

# Create auth.json
@"
{
  "OPENAI_API_KEY": "YOUR_API_KEY"
}
"@ | Out-File -FilePath "$env:USERPROFILE\.codex\auth.json" -Encoding utf8

Linux

# Create config.toml
cat > ~/.codex/config.toml << 'EOF'
model_provider = "codingflow"
model = "gpt-5.4"
model_reasoning_effort = "high"
disable_response_storage = true
preferred_auth_method = "apikey"

[model_providers.codingflow]
name = "codingflow"
base_url = "https://api.codingflow.ai/v1"
wire_api = "responses"
requires_openai_auth = true
EOF

# Create auth.json
cat > ~/.codex/auth.json << 'EOF'
{
  "OPENAI_API_KEY": "YOUR_API_KEY"
}
EOF

macOS

# Create config.toml
cat > ~/.codex/config.toml << 'EOF'
model_provider = "codingflow"
model = "gpt-5.3-codex"
model_reasoning_effort = "high"
disable_response_storage = true
preferred_auth_method = "apikey"

[model_providers.codingflow]
name = "codingflow"
base_url = "https://api.codingflow.ai/v1"
wire_api = "responses"
requires_openai_auth = true
EOF

# Create auth.json
cat > ~/.codex/auth.json << 'EOF'
{
  "OPENAI_API_KEY": "YOUR_API_KEY"
}
EOF

Important

Replace YOUR_API_KEY with the API Key you obtained from the Coding Flow platform.

Configuration parameters

• config.toml: Configuration file that specifies the model provider, model name, reasoning effort, whether to disable response storage, and auth method.
• model_provider: Model provider name. Set it to codingflow.
• model: Model name to use (e.g. gpt-5.4).
• model_reasoning_effort: Reasoning effort. Can be high, medium, or low.
• disable_response_storage: true disables storing API responses (no history saved).
• preferred_auth_method: Auth method. Set it to apikey.
• [model_providers.codingflow]: Model provider configuration section.
• name: Provider name. Set it to codingflow.
• base_url: Provider API base URL. Set it to https://api.codingflow.ai/v1.
• wire_api: API type to use.
• requires_openai_auth: Whether OpenAI auth is required.
• OPENAI_API_KEY: Authentication key. Set it to YOUR_API_KEY.

Step 3: Start using Codex

codex

FAQ

Q: The encrypted content gAAA...uw== could not be verified. Reason: Encrypted content could not be decrypted or parsed

A: The encryption/decryption keys used during interaction are inconsistent. Try closing the current session, clearing the cache, and starting a new conversation.

Q: Do I need to run the setup script from a specific directory?

A: No. You can run it from any directory; it will use the correct configuration location automatically.

Q: Can I use the editor plugin and CLI at the same time?

A: Yes. They share the same configuration and do not interfere with each other.

Q: How do I configure it for remote development (SSH)?

A: Run the setup script on the remote server. VS Code Remote will automatically use the remote server’s configuration.

Q: What if it doesn’t work after setup?

A: Check the following:

• Whether the API Key was copied correctly (no extra spaces)
• Whether the Base URL is correct
• Whether the network can reach the Codex service
• Restart your editor/terminal and try again

Q: How do I update the API Key?

A: Re-run the setup script, or update it manually in your editor settings.