Codex uses the Responses API under /v1. Put this in $CODEX_HOME/config.toml (by default ~/.codex/config.toml). $LLMAO_KEY is the personal access token from My Keys. The model id comes from the Models page. This example uses qwen3.8-27b.
model_provider = "llmao" model = "qwen3.8-27b" [model_providers.llmao] name = "llmao" base_url = "https://llm.apache.org/v1" env_key = "LLMAO_KEY" wire_api = "responses"
export LLMAO_KEY=<your personal access token> codex
codex -m qwen3.8-27b selects the model for one run. wire_api stays responses.