OpenAI Codex release notes: 0.164.0 adds inline session controls

OpenAI Codex CLI 0.164.0 lets you select model settings and permission profiles directly in slash commands. Codex CLI is OpenAI's terminal-based coding agent. The stable release was published on October 23 and is available through npm's latest channel.

Sources: OpenAI: release 0.164.0. npm: Codex package metadata.

OpenAI Codex release notes: select model settings inline

The command /model [model] --reasoning <level> --speed <tier> changes the current session without changing saved defaults. Square brackets indicate an optional model name; angle brackets mark value placeholders. Omitting the model applies the settings to the current model. Bare /model still opens the picker.

Codex checks model availability and supported reasoning levels and speed tiers before applying the change. Both spaces and equals signs work between a flag and its value.

Source: OpenAI: inline model, reasoning, and speed selection.

Human step: select a permission profile

A permission profile defines which actions the agent may perform. In the terminal interface, you can now select a built-in or custom profile with /permissions <profile-id>. For a review without file changes, type:

/permissions :read-only

Let the profile selection finish before submitting the task. Codex holds queued inputs until the selection is confirmed and retains them if selection is cancelled or fails. Existing feature requirements and confirmations still apply.

Source: OpenAI: inline permission profile selection.

Short example: use the new Codex feature

After selecting the profile, send this instruction to the agent:

Read the project's setup instructions and dependency files. Identify conflicting version requirements with file references. Suggest corrections without changing files or installing anything.

• The result references version requirements actually present in the project.
• The agent distinguishes contradictions from missing information.
• Files remain unchanged and no packages are installed.