Codex Configuration

Ensure you have Codex installed.

Open the ~/.codex directory, where ~ is your home directory.

Edit config.toml (create it if it doesn't exist) and add the following:

disable_response_storage = true
model = "gpt-5.5"
model_provider = "nitrorouter"
model_reasoning_effort = "xhigh"
model_verbosity = "high"

[model_providers.nitrorouter]
base_url = "https://api.nitrorouter.com/v1"
name = "nitrorouter"
requires_openai_auth = true
wire_api = "responses"

Next, edit auth.json (create it if it doesn't exist) and add the following:

{
  "OPENAI_API_KEY": "xxx"
}

Replace xxx with the API Key you created in the console.

After saving, run codex in your terminal and try chatting to verify if the configuration is successful.