Brendan Smith, Ph.D.

Look ma new Codex Updates! 0.119.0 and 0.120.0 are here. And with it, a HUGE number of quality of life updates and bug fixes! > Hooks now render in a dedicated live area above the composer. They only persist when they have output, so your terminal stays clean. If you're running PreToolUse or PostToolUse hooks, this is a huge readability win. > Hooks are now available again on Windows > CTRL+O copies the last agent output. Small but clutch when you're pulling a code block into another file or chat. > New statusline option: context usage as a graphical bar instead of a percentage. Easier to glance at mid-session when you're trying to gauge how much runway you have left. > Zellij support is here with no scrollback bugs. If you've been stuck on tmux just because Codex was broken in Zellij, you're free now (shout out @fcoury) > Memory extensions just landed. The consolidation agent can now discover plugin folders under memories_extensions/ and read their instructions.md to learn how to interpret new memory sources. Drop a folder in, give it guidance, and the agent picks it up automatically during summarization. No core code changes needed. This is the first real extension point for Codex's memory system, and it opens the door for third-party memory plugins. > Did you know, you can /rename a thread? But what's really cool about that is, after you rename it, you can resume it with the same name, no more UUIDs. codex resume mynewapp or directly from the TUI: /resume mynewapp > Multi agents v2 got an update to tool descriptions More reliable multi agent environments and inter agent communication > You can now enable TUI notifications whether Codex is in focus or not. Modify this in your config: [tui] notification_condition = "always" > MAJOR overhaul to Codex MCP functionality: 1. Codex Tool Search now works with custom MCP servers, so tools can be searched and deferred instead of all being exposed up front. 2. Custom MCP servers can now trigger elicitations, meaning they can stop and ask for user approval or input mid-flow. 3. MCP tool results now preserve richer metadata, which improves app/UI handoff behavior. 4. Codex can now read MCP resources directly, letting apps return resource URIs that the client can actually open. 5. File params for Codex Apps are smoother: local file paths can be uploaded and remapped automatically. 6. Plugin cache refresh and fallback sync behavior are more reliable, especially for custom and curated plugins. > Composer and chat behavior smoother overall, resize bugs remain though. > Realtime v2 got several significant improvements as well. > You're still reading? What a legend. 🫶 npm i -g @openai/codex to update

👋 If you’re new to Codex, here are 7 beginner tips for apps with Codex. (Bookmark it and use it tonight) 1. Start with: GPT-5.4 high That is high reasoning. It is enough. Don’t be tempted by "xhigh" unless working on something really tricky. It uses more tokens and will be slower to finish. 2. Sometimes, more reasoning may not help. You may need to give your agents better docs that are up to date. I prefer to have my agents create Markdown docs from DocSet that are local, instead of web scraping. I use DocSetQuery to create docs from Apple DocSet bundles. github.com/PaulSolt/DocSe… 3. Read @steipete's post to get started. Bookmark his blog and follow him. Read his post, it’s gold, and so are his other workflow posts. steipete.me/posts/2025/shi… 4. Copy aspects from Peter’s agents .md file and make it your own. There are thousands of hours of learning in his open-source projects. github.com/steipete/agent… Use the scripts too, things like committer for atomic commits are super powerful when multiple agents work in one folder. 5. Just talk to Codex. You don't need complex rules. You don't need to create huge Plan .md files. You can get really good results by just working on one aspect of a feature at a time, handing it off, and then letting Codex do it. If you get bored waiting, start up another project. Ask it to do something and then go back to the original one. Most likely, it will be done unless you're doing a huge refactor. 6. If you're making an iOS or macOS app, check out my App-Creator skill: super-easy-apps.kit.com/app-creator It's based on Makefiles and will give your agent eyes into your Xcode build failures and test failures. It needs this feedback loop to write working code and fix bugs. 7. You can always ask your agent to copy something from another project. Peter does this all the time and has agents leveraging work they’ve already done for new projects. I have my agents refer to previous project documentation or code patterns. See my app workflow video: How I use Codex GPT 5.4 with Xcode (My Complete Workflow): youtube.com/watch?v=ls9QaD… Enjoy your next app!