How to use Google Cloud Vertex AI as the model provider in Codex

Codex CLI 0.165.0 ships a built-in Google Cloud Vertex AI provider. You don't define a provider yourself; you only name it in the config file.

1. Update Codex to 0.165.0 or later.

npm install -g @openai/codex@0.165.0

1. Set the provider in ~/.codex/config.toml.

model_provider = "gcp"

The changelog gives only this one line; it doesn't describe project, region or auth settings.