Codex CLI 0.164: ten prompt preset slots, and changing reasoning effort keeps the cache
What is it?
Codex CLI is OpenAI's coding agent for the terminal. Version 0.164.0 lets you save frequently used prompts and slash commands into ten numbered /presets slots and pull them up from the keyboard. /model and /permissions now take arguments, so you can set model, reasoning effort, speed, and permission profile in one line, and enterprise MCP (the protocol for connecting external tools) servers can authenticate with Codex account grants or a dedicated sign-in. On the same day, OpenAI changed Codex and Work so that switching reasoning effort mid-conversation no longer invalidates the cache.
npm install -g @openai/codex@0.164.0Why does it matter?
A common pattern is low reasoning effort for quick tasks and high effort for hard ones, but until now each switch meant re-reading a long context, which cost money and time. Now you can change effort freely within one conversation. Credential masking for remote Bash commands and the Amazon Bedrock setup wizard (now on by default) are immediately useful for teams with strict security rules or those running Codex on AWS accounts.
Maturity
GAThis is a stable GitHub release (not a prerelease) listed in the official changelog. The cache behavior is confirmed only by the Codex lead's X post and isn't in the docs yet.
How to track it
- Docs: watch whether cache retention across reasoning-effort changes gets written into the ChatGPT & Codex changelog or the prompt caching docs.
- Next release: the 0.165.0 alpha is already out; check GitHub releases to see whether presets and MCP auth keep evolving when it goes stable.
- From the team: follow Tibo's (@thsottiaux) 'Day N' posts for changes to Codex usage limits and pricing.