← All guides
COD · Codex (OpenAI) · ~20 min · Medium

Codex SEO: llms.txt, Schema and robots.txt with OpenAI Codex

OpenAI Codex is a terminal-based AI agent that can read your entire project and make targeted edits. Run it once with the right prompt and it handles all GEO optimization tasks automatically.

Requires: OpenAI Codex CLI

Install: npm install -g @openai/codex. Needs an OpenAI API key with Codex access.

What we'll add:
  • Organization Schema — AI correctly identifies your business
  • FAQ Schema — +41% citation rate in AI responses
  • robots.txt — allow GPTBot, ClaudeBot, PerplexityBot
  • Specifics and freshness — explicit prices, facts and update dates are what AI actually cites
  • llms.txt — a short summary for AI agents; little to no effect on citations
0

Generate your GEO assets first

  1. Go to causabi.com
  2. Enter your site URL and run the audit
  3. Download the ZIP — it contains Schema.org, FAQ Schema, llms.txt, and robots.txt
  4. Save them to your project root as reference files (e.g., geo-assets/)
1

Run Codex with a GEO optimization prompt

Open your terminal in the project root and run:

Terminal
codex

Then paste this task description:

Codex Task Prompt
I need to add GEO optimization (structured data for AI search) to this project. Please do the following: 1. Add JSON-LD Organization Schema to the <head> of every page. The schema JSON is in geo-assets/schema.json. 2. Add JSON-LD FAQ Schema to the homepage <head> only. The FAQ schema is in geo-assets/faq.json. 3. Create or update public/robots.txt with the content from geo-assets/robots.txt. 4. Create public/llms.txt with the content from geo-assets/llms.txt. For Next.js App Router: add scripts to app/layout.tsx using next/script or direct script tags in metadata. For Vite/React: add to index.html <head>. For static HTML: add directly to each HTML file's <head>. Make sure all files are in the right location for the framework this project uses.
What Codex does

Codex will read your project structure, identify the framework, and make the exact file edits needed. It runs in a sandbox and shows you every change before applying.

2

Review and apply changes

  1. Codex will show a diff of all proposed changes
  2. Verify that Schema scripts appear in the right layout file
  3. Check that public/robots.txt and public/llms.txt were created
  4. Accept the changes
3

Deploy and verify

  1. Deploy your changes
  2. Check your-site.com/robots.txt and your-site.com/llms.txt
  3. Go to causabi.com → run a new audit — score should reach 70+
  4. Validate Schema: validator.schema.org

Check your own site right here

Enter your domain — we'll show your AI Score and the biggest reason ChatGPT and other AI engines can't see you.

Generate your GEO files for free

Causabi creates Schema.org, FAQ Schema, llms.txt, and robots.txt tailored to your specific site — ready for Codex to apply.

Generate GEO assets
Claude CodeCursorv0
Codex SEO — llms.txt, Schema and robots.txt with OpenAI Codex