daily nerding28 things Codex can do
28 things Codex can do
Riley Brown spends two hours on the 28 things he thinks you need to know about Codex, the ChatGPT desktop app's agent mode, running GPT-6 Astra. This page puts all 28 on one board: what you say, what Codex uses, what you get back.
Short on time? Read the signals. Want to try one? Go to step by step.
Original sources
The video
1:54:47 long, posted Sept 14, 2026. He says he filmed it in one sitting, from about noon to 11:05 p.m., and that it isn't sponsored.
The board
One tile per thing, grouped by what it's for. Pick a tile. The strip on top is the whole video to scale, so you can see where his time goes.
The two hours, to scale
01 App vs. model · 3:25 to 6:10 · 2:45 on screen
Start hereWhat you are looking at.
Build and shipFrom a prompt to a link.
The workspaceWhere the work sits.
Make thingsDocs, 3D, games, pictures.
Connect and automateYour apps, on a timer.
SkillsTeach it once, reuse it.
Hands offIt works while you don't.
The bar is time on screen. A dashed tile means you don't see it finish: ◐ starts but stops, ○ a clip or talk only.
Thing 1 of 28 · Start here
Watch at 3:25Codex is the app, Astra is the model
Codex is the desktop app. GPT-6 Astra is the model you pick inside it. Three things decide how good it is: what's built in, the model, and the plugins you add. You control the last two.
You do
Open the ChatGPT desktop app, switch to Codex, pick GPT-6 Astra, then type anything.
Codex uses
- ChatGPT desktop app
- Codex
- GPT-6 Astra
You get
Three panes: your list of chats, the chat you're in, and whatever the agent is working on.
● Shown live. Runs start to finish on camera.
Twelve signals
What matters beyond the feature list: how he actually works, what it costs, and where the video oversells. The small numbers jump to the things each signal comes from.
- 014:18
Codex is the app. Astra is the model.
Three things decide how good it gets: what's built in, the model, and your plugins. You pick the last two. His bet is that each new OpenAI model will be trained for Codex first, so it will do less in other apps. That's a prediction, not a test.
- 022:27
Start on $20. Try $100 for one month.
The $20 plan gets you some Astra. For long builds he says to pay for the $100 Pro plan for a single month and really use it.
- 0343:21
Everything is built on your computer first.
An app is just files in a folder, running on your machine until you ask for hosting. The same catch hits scheduled tasks and phone control: computer off, nothing runs. Tasks on GPT Work (the cloud icon) are the exception.
- 0418:01
Host on GPT Sites first. Your own stack later.
@sites comes with a database, storage and a ChatGPT sign-in, which suits personal and team tools. He hit a 15-site cap. For a real product he uses GitHub, Vercel and Convex, and has Codex walk him through the setup.
- 0522:41
Turn the effort dial on purpose.
He calls Astra “overkill” for most tasks. Light for filing chats, Medium for most work, High for app builds and anything that sets your priorities. Lower effort saves tokens.
- 0659:01
Plug everything in, then ask it what to do.
His “biggest wow”: with email, Slack, texts, Notion and meeting notes connected, he asked for one document planning his month, quarter and year, weak spots included. Day to day, he just asks what it can take off his plate.
- 071:22:22
Don't learn to write skills. Ask for them.
Three ways in: describe the format, record yourself doing it, or hand over an API's docs and key. Codex writes the skill every time. A plugin is a bundle of skills.
- 081:16:47
He reads before anything gets sent.
Email: draft first, then “send it.” Texts: an approval box for each message. The one place he lets go is Full access, so builds can run on his Mac without him clicking approve. He says staying on approve is fine if you want to be safe.
- 091:46:06
Sub-agents are faster, not cheaper.
Codex won't split a job across helpers unless you ask, because helpers burn more tokens per minute. His tip: a cheaper model for the helpers, Astra for the final answer.
- 1012:38
Plan for waiting.
He says 5 to 10 minutes for a site and up to an hour for a hard one. The iOS app he guessed at 5 to 7 minutes took 18:31. The game ran so long he moved on and came back. Start another chat while you wait.
Six of the 28 aren't fully shown.
16 and 27 lean on other people's clips. 20, 21 and 26 start but don't finish on camera. 28 is a pep talk. The other 22 run start to finish.
- 1230:25
His forecasts are forecasts.
Browser control faster than a person within about three months. Computer use ten times better and faster in six. Products “actually like Jarvis” within a year. None of that is demonstrated. It's what he expects.
Words on this page
Twelve terms, in plain words. Skip this if you already build with coding agents.
- Agent
- An AI that does the work, not just talks about it. In Codex it writes files, runs apps, tests them in its own browser and uses your connected apps.
- Model
- The AI that does the thinking inside the app. You pick it in the prompt bar. On this page it is GPT-6 Astra.
- Token
- The unit AI work is counted and paid in. Higher effort and more sub-agents use more of them.
- Plugin
- An add-on that connects Codex to another app, like Gmail, Slack, Notion or Vercel. A plugin is a bundle of skills.
- @ mention
- Typing @ and a name in the prompt, like @gmail or @sites, to tell Codex which plugin or skill to use. Skills also answer to /name.
- Localhost
- Your own computer acting as the server. An app on localhost runs only on your machine, so only you can open it.
- Push to prod
- His phrase for putting a change live. Prod is short for production, the version other people see. Until then the change stays on your computer.
- Stack
- The set of services a real app runs on. His is GitHub for the code, Vercel to put it online and Convex for the database.
- Repo
- Short for repository: one app's code, kept on GitHub. He asks Codex to create a private one for him.
- API and API key
- An API lets code use a web service directly. The key is a private code that ties that use to your account, which gets billed for it.
- Sub-agents
- Helpers the main agent starts so parts of a long job run side by side. Faster, but they use more tokens.
- Full access
- A setting in the prompt bar that lets Codex act on your computer without you clicking approve for each step.
Three pictures to keep
The three ideas that tie the 28 together. He never draws these; they are our summary of what he does.
1. Where your work lives
Every build starts on your computer. You move it up a step only when someone else needs to open it.
2. How hard to make it think
The effort setting sits next to the model name. These are the jobs he sets each level for on camera.
Light
Easy chores. Saves tokens.
Medium
The default. Most work.
High
Builds, and anything that sets your priorities.
3. Three ways to get a skill
A skill is a saved way of doing one job. You never write one. You give Codex one of these and it writes the skill.
- 19
Describe it
Point at one good example and name the format.
1:18:56 - 20
Show it
Record your screen while you do the job by hand.
1:22:54 - 21
Hand it an API
Give it a service's docs link and your key.
1:26:45
All three end here
A skill
Call it from any chat with @name or /name, including from your phone. Plugins are bundles of these: Notion's has 4, Vercel's has 54.
Shown, or just said
Of the 28, 22 run start to finish on camera. 3 start and stop. 3 are a clip from someone else or talk only.
- Shown live · 22 · Runs start to finish on camera.
- Partly shown · 3 · Starts on camera, doesn't finish.
- Not shown live · 3 · Someone else's clip, or talk only.
- 16
Learning sites
He shows two sites made by someone else (Ash) and says the prompt. He doesn't build one.
1:09:24 - 20
Record + replay
He stops here: “creating this skill is going to take forever.” The finished skill isn't shown.
1:22:54 - 21
APIs in skills
Explained using skills he already has. No new one is built on camera.
1:26:45 - 26
Sub-agents
The helpers start. He doesn't wait for the result.
1:45:17 - 27
Computer use
He plays a clip and says to try it yourself. There's no session of his own.
1:48:09 - 28
Whatever you want
A pep talk, then the recap. Nothing new is demonstrated.
1:49:35
Two more worth knowing: the iOS app in thing 04 took 18:31, not the 5 to 7 minutes he guessed, and the game in thing 15 took long enough that he cut away and came back.
Step by step
Every thing, with the steps to try it yourself. Open one, or search for a tool or an @mention. Timestamps open the video at that moment.
28 of 28
01
Codex is the app, Astra is the model
Codex is the desktop app. GPT-6 Astra is the model you pick inside it. Three things decide how good it is: what's built in, the model, and the plugins you add. You control the last two.Start hereHow to · 5 steps ▾Hide steps ▴How to
- Download the ChatGPT desktop app (Mac or Windows). The $20 plan works; he suggests one month of the $100 Pro plan for long builds.
- Top-left menu: switch from Chat or Work to Codex.
- Learn the three panes: chats on the left, the active chat in the middle, the work on the right. Either side can be hidden.
- In the prompt bar, pick GPT-6 Astra and a thinking effort: Light, Medium or High.
- Add plugins later. Model and plugins are the two dials you control.
You do
Open the ChatGPT desktop app, switch to Codex, pick GPT-6 Astra, then type anything.
You get
Three panes: your list of chats, the chat you're in, and whatever the agent is working on.
Codex uses
- ChatGPT desktop app
- Codex
- GPT-6 Astra
In the video
3:25 · ● Shown live
02
It can build any app
Describe an app, or a change to one, and Codex writes it, runs it on your computer and tests it in its own browser. Web apps, sites and browser games all count.Build and shipHow to · 5 steps ▾Hide steps ▴How to
- Open a coding project and ask Codex to run it locally.
- Screenshot the part you want changed, drag it into the prompt and say what you want.
- Watch it edit, then test in the in-app browser, including a phone-width check.
- Happy? Say “push it to prod.” It updates GitHub and the live site.
- Heavy 3D games: use Open in → Chrome. The in-app browser is slower for those.
You say
Drag in a screenshot of a homepage section: “I don't love this part. Make a new version that matches the rest of the page.”
You get
The change, running locally and checked at phone width. Nothing goes live until you say “push it to prod.”
Codex uses
- localhost preview
- In-app browser
- GitHub
In the video
6:10 · ● Shown live
03
It can host sites with GPT Sites
A hosting feature built into Codex. One prompt gets you a site on the internet with a database, file storage and a ChatGPT sign-in. He recommends it for your first build.Build and shipHow to · 5 steps ▾Hide steps ▴How to
- New chat. Type @sites, or just say you want a GPT Site.
- Describe the app, who is allowed in, the inputs and what it should show.
- Send it on GPT-6 Astra. Expect 5 to 10 minutes; hard ones can run 30 to 60.
- Open the link in the in-app browser or any browser. Sign in with Continue with ChatGPT.
- For a live dashboard: add a scheduled task that reads @Notion, @Gmail, @Slack and @Messages and writes to the site's database.
You say
“Make a @sites property calculator for Arizona houses: rent it or flip it? Private. Only my company's email addresses can sign in.”
You get
A live *.chatgpt.site link a few minutes later that only your team can open.
Codex uses
- @sites
- Built-in database
- ChatGPT sign-in
In the video
10:32 · ● Shown live
He hit a cap of 15 sites two weeks before filming and doesn't know if it will be raised.
04
Desktop apps and iOS apps, not just web
Small Mac apps for your own use, and iPhone apps written in Swift that run in a simulator inside Codex.Build and shipHow to · 5 steps ▾Hide steps ▴How to
- Desktop: turn on Full access in the prompt bar, or be ready to click approve a lot.
- Say what the app does and ask Codex to run it on your computer when it's done.
- His example: a pop-up image search that copies pictures, remembers the ones you used and removes backgrounds.
- iOS: Cmd+N, describe the app, ask for a Swift app and the Build iOS Apps plugin, set effort to High.
- When it finishes, open the side panel and tap around the simulator.
You say
“Make a desktop app that opens with Cmd+Shift+Space and does ___. Make it look like Raycast. When you're done, run it on my computer.”
You get
A hotkey app running on your Mac. For iOS: a working iPhone simulator in the side panel.
Codex uses
- Full access
- Build iOS Apps plugin
- Swift
- iOS simulator
In the video
18:12 · ● Shown live
He guesses 5 to 7 minutes for the iOS app. On screen it took 18 minutes 31 seconds.
05
The built-in web browser
A full browser inside Codex, signed in to your accounts. You can use it yourself, and Codex can drive it: open tabs, scroll, click and test your apps. He says he does 90% of his work in it.The workspaceHow to · 5 steps ▾Hide steps ▴How to
- Toggle the right side panel and pick Browser, or press Cmd+T. Full-screen it if you like.
- Any link Codex gives you (Notion, Gmail, a doc): right-click → Open in browser.
- Ask for changes to the open page: “add an outro at the bottom of this Notion doc.”
- Ask it to browse: “in the Codex browser, open Instagram, Twitter and LinkedIn.”
- Browser settings → Import cookies and passwords from Chrome, so you're signed in everywhere.
You say
“Use @browser to test this UI and see if everything works.”
You get
It clicks through every field, tries edge cases, checks phone width and reports what broke.
Codex uses
- Browser panel
- Cmd+T
- @browser
- Chrome import
In the video
24:09 · ● Shown live
06
It can create any document
Three built-in plugins make slide decks, spreadsheets and documents, each with templates. They open inside Codex.Make thingsHow to · 4 steps ▾Hide steps ▴How to
- Pick the Documents, Spreadsheets or Presentations plugin. Choose a template if you want one.
- On any app window, press both Cmd keys together. That sends a screenshot plus info about the app to Codex.
- Ask for a @presentation or a @spreadsheet from it.
- Flip through the result in the Codex viewer.
You say
Press both Cmd keys on a Notion page to send an AppShot, then: “Turn this into a @presentation.”
You get
A deck with speaker notes and sources. Or a comparison spreadsheet with tabs for pricing, features and sources.
Codex uses
- @documents
- @spreadsheets
- @presentations
- AppShots
In the video
32:27 · ● Shown live
07
Annotation mode: point at what to change
Click on any part of a slide or a live site, leave a note there, repeat, then send every note at once. Codex knows where each note points.Make thingsHow to · 4 steps ▾Hide steps ▴How to
- Open a presentation or a site inside Codex.
- Click Annotate in the top bar.
- Click a spot, type what's wrong, add it. Repeat as many times as you like.
- Hit Send. You can add more notes while it's still working.
You say
Pins on the page: “too dark”, “make this top bar less tall”, “get rid of this”, “make this background dotted graph paper.”
You get
All the notes applied in one pass. Seven at once in his demo.
Codex uses
- Annotate button
- Works on documents
- Works on sites
In the video
35:00 · ● Shown live
08
Build and deploy production-ready apps
When a GPT Site isn't enough: your code in GitHub, hosting on Vercel, a Convex database and your own domain. He has never written code. He asks Codex for the stack, then asks it to set everything up.Build and shipHow to · 5 steps ▾Hide steps ▴How to
- Ask Codex: what's the best stack for this app? Then ask it to help you sign in to each tool.
- “Create a new private GitHub repo with all of these files.”
- “Keep the repo connected to Vercel, deploy it, and give me the Vercel link.”
- Need a database? Ask for one with @convex.
- Buy a domain (he uses Namecheap) and point it at the Vercel site.
You say
“Help me get set up so you can fully control GitHub, Vercel and Convex. Walk me through signing in to all of them.”
You get
A private GitHub repo and a vercel.app link. After that, “use @convex for the database” just works.
Codex uses
- GitHub
- Vercel
- Convex
- Namecheap
09
Chats or projects
A plain chat lands in Recents; he uses that for 90% of tasks. A project is a folder on your computer, and every chat in it sees the same files. He only uses projects for real apps.The workspaceHow to · 4 steps ▾Hide steps ▴How to
- One-off task: New chat. It shows up under Recents and names itself.
- Bigger build: Projects → new project → give it a name.
- Right-click the project → Reveal in Finder to see its folder (~/Documents/ChatGPT/your-project).
- Start chats inside the project. They all read and write the same folder.
You say
Plain chat: “Tell me about my latest emails using @gmail.” Project: name it, then start chats inside it.
You get
Auto-named chats in Recents, or a project folder that keeps every file for one app together.
Codex uses
- Recents
- Projects
- Cmd+N
- Documents/ChatGPT folder
In the video
44:29 · ● Shown live
10
Run many jobs at once, plus side chats
Start a second, third or fourth job while the first is still running. In a project they share the folder. A side chat is a small throwaway chat for questions.The workspaceHow to · 4 steps ▾Hide steps ▴How to
- While a job runs, press Cmd+N in the same project and send another prompt.
- Set the effort per chat: High for the hard one, lower for the easy one.
- Type /side for a temporary chat that knows what you're working on.
- Close the side chat with the X when you're done.
You say
Cmd+N while one job runs, then a new prompt. Or type /side to ask a quick question about the work.
You get
Several jobs building at the same time, and a side chat that can read the files but isn't meant to build anything.
Codex uses
- Cmd+N
- /side
- Shared project folder
In the video
48:54 · ● Shown live
11
Organize chats into sections
Sections are folders for chats in the sidebar. You can make them by hand, or ask Codex to find the right chats and file them for you.The workspaceHow to · 3 steps ▾Hide steps ▴How to
- By hand: right-click a chat → Section → New Section → name it.
- By asking: describe which chats belong and name the section. Light effort is enough.
- Done with it? “Delete the roundup section.” The chats themselves are kept.
You say
“Every chat from the past week where I asked you to gather info from Gmail, Slack or Notion: add it to the roundup section.”
You get
25 chats filed into one section. Delete the section later and the chats stay.
Codex uses
- Sidebar sections
- Light effort
12
Connect every app you already use
Plugins connect Codex to Gmail, Slack, Notion, Calendar, Messages, Google Docs and many more. Type @ and the app's name to use one. No plugin for your app? Ask Codex how to connect it and it will try.Connect and automateHow to · 5 steps ▾Hide steps ▴How to
- Sidebar → Plugins. Browse and install the apps you use.
- In a prompt, type @notion, @slack, @gmail, @calendar or @messages.
- For anything that decides your priorities, turn the effort up to High.
- No official plugin (his example: Blender)? Ask “how do I connect this app to Codex?”
- Design tools work too: he has it draw three landing pages on a Paper board, then copies a link to one element to give feedback on it.
You say
“Give me a brief of the important updates across my company, most urgent first. Check @messages too. Put it in a Google Doc.”
You get
One prioritized brief in a Google Doc, opened in the in-app browser.
Codex uses
- @notion
- @slack
- @gmail
- @messages
- Google Docs
- Paper
- Blender
13
Ask Codex what to work on
Once your apps are plugged in, you don't need a plan. Ask Codex to look at everything and pick work it can take off your plate.Connect and automateHow to · 3 steps ▾Hide steps ▴How to
- New chat, outside any project.
- Ask what it can take off your plate and tell it to draft the work, not just list it.
- Read each draft. Edit, or tell it to send.
You say
“I have a lot on my plate. What three things can you take off it? Look at all my connections and draft whatever you can.”
You get
Three drafts: a talk outline, a Slack message and an email plan. Read them, then say “send all three.”
Codex uses
- High effort
- Slack
- Gmail
- Notion
In the video
1:03:17 · ● Shown live
14
Work inside Blender and make 3D assets
Blender is a free 3D app. Codex can control it: make models from a description, then change them when you point at what's wrong.Make thingsHow to · 4 steps ▾Hide steps ▴How to
- In a project chat, describe the models and say “use Blender.”
- Right-click the project → Reveal in Finder, then open the .blend file.
- Screenshot the model, draw an arrow at the problem, paste it into the chat with your change.
- Switch back to Blender and watch the change land.
You say
A screenshot with an arrow drawn on it: “Change this colour to gold, fix the thing sticking out, make the small mouse chrome black.”
You get
Five 3D mouse-shaped cars as Blender files. Edits show up in Blender as it works.
Codex uses
- Blender
- Project folder
- Marked-up screenshot
In the video
1:05:39 · ● Shown live
15
Make a playable video game
Take the 3D models from Blender, put them in a game with physics and a controls menu, and publish it to a link.Make thingsHow to · 4 steps ▾Hide steps ▴How to
- In the game's project chat, point at the Blender models and ask for them in the game.
- Ask for a controls menu and a deploy to @vercel (or a GPT Site).
- Open the link in Chrome, not the in-app browser.
- Want friends in? Ask “how do I make this multiplayer?”
You say
“Put those five mouse cars into this game. Add a menu that explains the controls. Deploy it to @vercel so I can play.”
You get
“Click Kick”: car soccer with computer mice, playable at a vercel.app link.
Codex uses
- Blender assets
- @vercel
- High effort
In the video
1:08:25 · ● Shown live
The build ran long. He moves on to thing 16 and comes back to play it at 1:11:06.
16
Interactive learning websites
Sites that teach with a 3D model you can pull apart: the human body, a Tesla. Hover over a part to read about it.Make things· ○ Not shown liveHow to · 3 steps ▾Hide steps ▴How to
- Make or get a 3D model (see thing 14).
- Ask for a site where the model splits into labelled parts.
- Ask for it on @sites, public, and share the link.
You say
“Take this 3D asset and make it so I can pull it apart and see every part. Put it on @sites and make it public.”
You get
A public link to an explorable model you can send to friends.
Codex uses
- A 3D model
- @sites
In the video
1:09:24 · ○ Not shown live
He shows two sites made by someone else (Ash) and says the prompt. He doesn't build one.
17
Scheduled tasks
Any chat can repeat on a timer. Codex gets the same instructions at the set time and answers in the same chat.Connect and automateHow to · 3 steps ▾Hide steps ▴How to
- Open the chat you want repeated and say when to run it.
- Click the task to check its instructions, frequency and “runs in.”
- Pin that chat, or ask Codex to make an “automations” section and move every scheduled chat into it.
You say
In a chat that did something useful: “Do this at 10 a.m. on Mondays, Wednesdays and Fridays.”
You get
A task card showing the instructions, the frequency and which chat it replies in.
Codex uses
- Scheduled
- GPT Work (cloud)
- Sections
In the video
1:13:12 · ● Shown live
Local tasks don't run when your computer is off. The ones with a cloud icon run on GPT Work.
18
Control your email and iMessage
Codex reads and summarizes your email, drafts replies and sends them when you say so. It can send texts through Messages the same way.Connect and automateHow to · 4 steps ▾Hide steps ▴How to
- Ask for a summary of the emails that matter and a draft reply.
- Read the draft. Say “send it as is” or ask for changes.
- Ask for a link to the sent email and open it in the in-app browser.
- “Also text this to her.” Click Continue on the approval for each message.
You say
“Look at the latest emails from Emily. Summarize them and draft a reply so I can approve it.”
You get
A draft. After “send it”: the sent email plus a link to it. Texts go out after you click Continue.
Codex uses
- @gmail
- @messages
- Voice dictation
In the video
1:16:19 · ● Shown live
19
Turn repeated work into skills
A skill is a saved way of doing one job. Plugins are bundles of skills: Notion's has 4, Vercel's has 54. You don't write skills. You ask Codex to.SkillsHow to · 3 steps ▾Hide steps ▴How to
- Do the job well once by hand, so there's an example.
- Ask Codex to turn that format into a skill and give it a name. Medium effort is enough.
- In a new chat, type / or @ and the skill's name, then your topic.
You say
Point at a video outline you're proud of: “Make a skill that writes outlines in this format. Call it golden long form.”
You get
A skill you can call from any chat with /golden long form or an @mention.
Codex uses
- Skills
- A good example to copy
- Medium effort
In the video
1:18:56 · ● Shown live
20
Record and Replay
For jobs that are easier to show than to describe. Codex records your screen while you do the work by hand, then turns what it saw into a skill.Skills· ◐ Partly shownHow to · 3 steps ▾Hide steps ▴How to
- Call @Record & Replay and say what the skill is for.
- Wait for the recorder to appear, then do the job by hand. His example: making thumbnails in Paper.
- Go back to Codex and hit stop. It reviews the recording and starts building the skill.
You say
“@Record & Replay: record my screen, then we'll turn it into a skill.”
You get
A recording Codex reviews, then a skill that repeats the same clicks.
Codex uses
- @Record & Replay
- Screen recording
- Computer use
In the video
1:22:54 · ◐ Partly shown
He stops here: “creating this skill is going to take forever.” The finished skill isn't shown.
21
Give skills outside APIs
Many paid web services can be driven by code through an API. Give Codex the service's docs and your key, and it builds a skill that uses the service.Skills· ◐ Partly shownHow to · 4 steps ▾Hide steps ▴How to
- Sign up with the service and add billing. These cost money to use.
- Copy your API key and the link to the service's documentation.
- Give both to Codex and ask for a skill.
- Call it by name, for example @scrape creators.
You say
“Turn this API into a skill. Here's the documentation link. Here's my API key. I want everything it can do.”
You get
3 to 5 minutes later: a skill that can scrape social posts, search, or cut out image backgrounds.
Codex uses
- ScrapeCreators
- SerpAPI
- remove.bg
- Fal
In the video
1:26:45 · ◐ Partly shown
Explained using skills he already has. No new one is built on camera.
22
A video understanding skill
Codex on its own cuts a video into frames, which is slow. Google's Gemini can watch a whole video quickly. His skill hands the video to Gemini and brings the notes back to Codex.SkillsHow to · 4 steps ▾Hide steps ▴How to
- Go to aistudio.google.com and get an API key.
- Build the skill as in thing 21, or download his from agentnative.inc.
- Drag a video into the prompt and ask your question. Medium effort.
- Codex may send it to Gemini twice: once for the words, once for the visuals.
You say
Paste in an .mp4: “This video didn't do well. Use the video analyze skill and tell me why. How do I fix the script and the visuals?”
You get
A critique of the whole clip in 3-second chunks, and a rewritten script to re-record.
Codex uses
- Gemini API key
- Google AI Studio
- Video analyze skill
In the video
1:30:00 · ● Shown live
He says Gemini is “not that great of a model” as of Sept 8, 2026, except for this one feature.
23
Inline charts, right in the chat
Codex can draw flowcharts and sequence diagrams (Mermaid) inside its reply. No file and no extra skill needed.Make thingsHow to · 2 steps ▾Hide steps ▴How to
- Ask for inline charts or Mermaid diagrams, and say not to make an artifact.
- Like the result? “Turn this into a skill, and put in your memory that I prefer visuals.”
You say
“Show me your ideas as inline Mermaid diagrams. Don't create an artifact.”
You get
Diagrams in the chat instead of a wall of text.
Codex uses
- Mermaid diagrams
- Memory
In the video
1:35:51 · ● Shown live
24
Control Codex from your phone
The ChatGPT phone app can remote-control Codex on your computer: start chats, run skills, see charts, talk to it by voice.Hands offHow to · 4 steps ▾Hide steps ▴How to
- On the desktop: Settings → search “remote” → Connections and remote → Add a device.
- Scan the QR code with your phone and confirm.
- On the phone: open projects, chats and pinned automations, or start a new chat.
- Tap the real-time voice button and tell it what to start.
You say (out loud)
“Spin up a new chat on GPT-6 Astra and make me a small GPT Sites report on this.”
You get
A new chat running on your computer, started from wherever you are.
Codex uses
- ChatGPT phone app
- Remote connection
- QR code
- Real-time voice
In the video
1:38:03 · ● Shown live
Your computer has to be on. The phone only steers the desktop app.
25
Generate and edit images
Codex makes images, then lets you pin comments on parts of the picture and redo just those. He calls it a replacement for Photoshop.Make thingsHow to · 4 steps ▾Hide steps ▴How to
- Ask for the image and attach any pictures it should use.
- Click the result to open it, then click the comment button.
- Pin notes on the parts to change.
- Hit Make edits.
You say
“Make a thumbnail in my style. Swap the logo for this one. The text should say ‘28 things you need to know.’”
You get
The image. Then, after pins like “make the shirt white” and “more stars”, an edited version.
Codex uses
- Built-in image tool
- Comment pins
In the video
1:42:49 · ● Shown live
26
Sub-agents for long tasks
One agent does a long list one item at a time. Ask for sub-agents and helpers do the items side by side, then report back to the main agent.Hands off· ◐ Partly shownHow to · 3 steps ▾Hide steps ▴How to
- Write the task, then add “use sub-agents for each one.”
- To save tokens: ask for a cheaper model for the helpers and Astra for the final analysis.
- Open the sub-agents summary and click a helper to see what it's doing.
You say
“Research these YouTubers and pull their last 10 videos with @scrape creators. Use sub-agents for each one.”
You get
Three helpers working in parallel. The main agent writes the final answer.
Codex uses
- Sub-agents panel
- @scrape creators
- Medium effort
27
Computer use
Codex moves the mouse and types, in any app on your computer. On a Mac it can do this in the background while you use something else.Hands off· ○ Not shown liveHow to · 3 steps ▾Hide steps ▴How to
- Type @computer in a prompt.
- Describe the job in an app on your computer.
- Minimize Codex if you want. It keeps going in the background on a Mac.
You say
Start a prompt with @computer, then say what to do on your machine.
You get
Codex doing the clicking. His example is a clip of it drawing a portrait in Canva, stroke by stroke.
Codex uses
- @computer
- Any desktop app
In the video
1:48:09 · ○ Not shown live
He plays a clip and says to try it yourself. There's no session of his own.
28
Whatever you want
Not a feature. His closing point: if it can happen on a computer, there is probably a way to get Codex to do it, so stop waiting for a list.Hands off· ○ Not shown liveHow to · 2 steps ▾Hide steps ▴How to
- Pick one thing you do on a computer every week.
- Ask Codex how it would do it, with the apps you already have connected.
He says
Use your imagination.
You get
A two-minute recap of all 28, starting at 1:50:48.
Codex uses
- Everything above
Try it, smallest version first
Four of the 28, in this order. Each one uses what the one before gave you. The four and the order are our pick; what to type comes from his video. The starter prompt at the bottom is ours.
- 01
Open Codex and pick the model
Everything else starts here. The $20 plan is enough to begin. Leave effort on Medium for now and keep clicking approve.
You do
Open the ChatGPT desktop app, switch to Codex, pick GPT-6 Astra, then type anything.
Codex uses
- ChatGPT desktop app
- Codex
- GPT-6 Astra
You get
Three panes: your list of chats, the chat you're in, and whatever the agent is working on.
- 02
Put one small tool online with GPT Sites
His pick for a first build: one prompt, and the database and sign-in come with it. Set effort to High and expect 5 to 10 minutes.
You type
“Make a @sites property calculator for Arizona houses: rent it or flip it? Private. Only my company's email addresses can sign in.”
Codex uses
- @sites
- Built-in database
- ChatGPT sign-in
You get
A live *.chatgpt.site link a few minutes later that only your team can open.
- 03
Fix it by pointing, not describing
Open your new site inside Codex, pin a note on each thing you don't like, then send them all at once.
You type
Pins on the page: “too dark”, “make this top bar less tall”, “get rid of this”, “make this background dotted graph paper.”
Codex uses
- Annotate button
- Works on documents
- Works on sites
You get
All the notes applied in one pass. Seven at once in his demo.
- 04
Turn one thing you do well into a skill
Pick something you've already done well once, like an email or an outline. Codex writes the skill. Medium effort is enough.
You type
Point at a video outline you're proud of: “Make a skill that writes outlines in this format. Call it golden long form.”
Codex uses
- Skills
- A good example to copy
- Medium effort
You get
A skill you can call from any chat with /golden long form or an @mention.
For step 2, if you don't have an idea yet: fill in the blanks and paste it into a new Codex chat on GPT-6 Astra.
FakeNerd starter · your first GPT Site
Make a @sites ___ (what it is, in one line) for ___ (who uses it). Private: only ___ (your email, or your team's email addresses) can sign in. It takes ___ (the inputs) and shows ___ (what you want to see). Keep it to one page. When it's live, give me the link.
FakeNerd's take
Start with a GPT Site, then one skill
He recommends GPT Sites (03) for a first build, and we agree: one prompt, a link you can open, nothing to set up. Then turn one thing you already do well into a skill (19). Those two teach you most of the other 26.
Most of it is real. The futuristic part isn't.
22 of the 28 run start to finish on camera, which is a good ratio for a two-hour course. The six that don't are mostly the hands-off ones: record and replay, sub-agents, computer use. Treat those as promises until you've run one yourself.
Not sponsored, still one company's tour
He says no one paid for it. But every answer is an OpenAI feature: GPT Sites before your own hosting, a $100 Pro month for long builds, and his bet that new models land in Codex first. His written guide asks for a sign-up after the second item.
Keep clicking approve for now
He reads every email and text before it goes out. The one place he lets go is Full access on his own Mac, and he says staying on approve is fine. For a beginner, slower and safe beats fast and surprised.
Same model as the ideas wall, different job
The Astra ideas wall is two people talking about what to hand an agent in a business. This is one person clicking through the app. Learn the buttons here, then go there for what to point them at.
Related on this site: Astra ideas wall, the same model from the business side. Give ChatGPT a job, a beginner's guide to Work, the mode next to Codex in the same app. Git and GitHub for beginners, the first piece of the stack in thing 08.
About this page
One video, one person's way of working. The 28 names and start times are his own chapter list. The rest comes from the video's captions. Prices, limits, model names and timings are as he says them. We haven't checked them.
- The “you say” lines are shortened from what he types or says. They show the shape of the ask, not his exact words.
- The lanes on the board, the three pictures and the shown-or-said marks are ours, not his.
- Not covered: getting an app into the App Store and wiring up a domain. He promises separate videos for both.
Video: youtu.be/ifz8NGHuHtY (Riley Brown). His written version of the guide is at agentnative.inc; it asks for a sign-up after the second item.