OpenAI Codex workflow course

Course goal: ship your personal brand site

Build a personal brand site with Codex

Keep improving one project from an empty folder to a responsive one-page site with an introduction, projects, and contact details. Every lesson adds a visible result or a check toward that finish line.

Curriculum

Personal brand site build path

Start With Codex

Set up Codex and build the hero section of your personal brand site.

0/4

00｜Install And Open CodexInstall the desktop app, sign in, open the site project folder, and send a safe first message.What Codex Is ForBuild the first version of your site with a name, introduction, projects, contact details, and one working button.Choose A Codex SurfaceEdit the site's Projects button locally, then verify its text and behavior in a browser.Your First Useful PromptTurn “add an About section” into a concrete request with content, constraints, and browser checks.

Prompt Like A Builder

Map the site, plan its sections, and turn rough ideas into clear changes.

0/3

Find the Files to ChangeAsk Codex to show which files control each part of the site before you edit anything.Plan Before CodingPlan the site's theme control before editing, including risks and browser checks.

10 minReady

Plan Before Coding

Use a plan to reduce surprise before Codex edits production files.

implementation sequenceblast radiusreview checkpoints

10-minute lab

Hands-on lab

Plan a small light/dark theme switch for the mapped personal brand site. This lesson ends with an approved plan, not edited code.

Before you start

Keep the file and feature notes from the previous lesson available for reference.
Open my-brand-site and start a new task named Plan theme switch.

Do it now

Copy and send the planning prompt below.Confirm the plan keeps the project to one index.html file and adds no packages.Check that the plan names the UI control, theme styles, JavaScript behavior, and browser checks.Ask for one revision if any step is vague, then explicitly approve the final plan without implementing it yet.

Good prompt

Codex, inspect index.html and propose a three-step plan for adding an accessible light/dark theme switch. Keep the project in one file, add no packages, and preserve the existing Projects button and section navigation. Include the exact behavior, likely risks, and browser checks at wide and narrow widths. Do not edit until I approve the plan.

What success looks like

Codex returns a short ordered plan and makes no file changes.
The plan identifies the exact file and the visible behavior to add.
Verification covers clicking the switch and checking both wide and narrow layouts.

Stuck? Try this

If Codex edits immediately, reply: “Stop after planning and revert any implementation changes.”
If the plan says only “update CSS and JS,” ask it to name the specific UI state and manual checks.

Plain-language explanation

Planning first means Codex explains the likely sequence before it edits files. The plan should name files, order of changes, tests, and risks.

You do not need a huge plan. For most beginner tasks, a three-step plan is enough to catch misunderstandings before code changes happen.

Why it matters

A short plan gives you a review checkpoint. It is much cheaper to correct a plan than to untangle a wrong implementation.

Common beginner mistake

Beginners often let Codex start editing immediately, then review a diff that is larger than expected.

Step-by-step

Tell Codex the task is ambiguous or multi-file.
Ask for a small plan before edits.
Require the plan to name tests or manual checks.
Approve or revise the plan before implementation.

Try this

Choose a change that touches more than one file. Ask Codex for a plan and reject any plan that does not name verification.

Completion checklist

The plan names files likely to change.
The plan includes a test or manual check before implementation begins.

Sources

Define Done WhenDefine visible completion checks, then implement the site's light and dark themes.

Work Safely

Add site interactions while keeping every edit safe and easy to undo.

0/3

Local Thread BoundariesAdd Back to top while keeping the task limited to one file and one visible outcome.Sandbox And ApprovalsServe the personal site locally and review every command before approving it.Network Access RiskAudit fonts, images, scripts, and links to decide whether the site needs network access.

Ship Verified Changes

Test the site, check desktop and mobile views, and review the final diff.

0/3

Test The ChangeAdd focused checks for the site's theme and navigation without breaking earlier work.Browser VerificationOpen the real site and check content, navigation, and layout at desktop and mobile widths.Review Before AcceptingReview the site's full diff, test evidence, and any remaining visual or behavior risks.

Lock In Your Site Rules

Write project rules that preserve the site's content and visual style.

0/3

Write Your Site RulesWrite an AGENTS.md for my-brand-site so later edits keep the same voice, layout, and checks.Separate Site And Section RulesKeep permanent site rules separate from one-time requests for the Projects or Contact section.Turn Site Mistakes Into RulesTurn missed labels, broken links, or mobile overflow into rules that prevent the same problem next time.

Finish The Site Details

Use the app, CLI, or cloud where each remaining site task fits best.

0/3

Polish The Site In The AppUse the Codex app to polish one Projects card, review the diff, and check the result at two widths.Run Site Checks In The CLIUse the terminal to catch duplicate IDs, missing section links, and whitespace errors in the single-file site.Delegate An Isolated Site TaskHand off a bounded content or accessibility audit without opening the door to a full redesign.

Build A Site QA Workflow

Create reusable checks for the site's content, links, and browser behavior.

0/3

Turn Site Checks Into A SkillPackage the personal site's pre-launch content, link, mobile, and accessibility checks into one reusable skill.Bring In Project Data SafelyDecide whether project cards need outside data, and use the smallest read-only connection only when it adds value.Test Contact SafelyTest the Contact section with sample data and stop before anything is sent to a real service.

Finish And Deliver The Site

Polish independent tasks in parallel, then complete one final acceptance review.

0/3

Complete The Site GoalTurn the finished personal site into one measurable goal with content, layout, interaction, and evidence checks.Polish Copy And Accessibility In ParallelUse isolated worktrees only when copy polish and accessibility review can avoid editing the same lines.Run The Final Three ReviewsRun separate content, link, and accessibility reviews, then compare all evidence against the same launch checklist.

Practice lab

Copyable Codex prompts