Install

Install the Codex CLI. For the desktop app, see Codex App.

npm install -g @openai/codex

Usage with Ollama

Note

Codex requires a larger context window. It is recommended to use a context window of at least 64k tokens.

Quick setup

ollama launch codex

When launched through ollama launch codex, Ollama refreshes the model catalog and uses a dedicated Codex profile for that session.

To configure without launching:

ollama launch codex --config

To remove the Ollama launch profile and generated model catalog:

ollama launch codex --restore

Manual setup

To use codex with Ollama, use the --oss flag:

codex --oss

To use a specific model, pass the -m flag:

codex --oss -m gpt-oss:120b

To use a cloud model:

codex --oss -m gpt-oss:120b-cloud

Profile-based setup

For a persistent Codex CLI configuration, create ~/.codex/ollama-launch.config.toml:

model = "gpt-oss:120b"
model_provider = "ollama-launch"
model_catalog_json = "/Users/you/.codex/model.json"

[model_providers.ollama-launch]
name = "Ollama"
base_url = "http://localhost:11434/v1/"
wire_api = "responses"

Then run:

codex --profile ollama-launch