Codex SEO: Fix Your Site's SEO from Codex

Codex can rewrite a metadata function in one pass. What it cannot do alone is see which of your pages Google ignores. Add SEOmatic and Codex reads your real Search Console data, audits your live site and checks indexing, then fixes the cause in your repo, in the CLI or the IDE extension.

codex mcp add, then sign in once in the browser
Search Console and URL Inspection next to your code
Runs headless with codex exec for CI checks

Connect Codex free

Codex

About SEOmatic for Codex

SEOmatic is a hosted MCP server that Codex calls over HTTP. It gives Codex SEO tools that run on your live site and your Google Search Console, so the code changes it makes target pages that are really losing traffic.

Last Updated

November 2026

Requirements

Codex (the CLI, the IDE extension, or Codex inside the ChatGPT desktop app) signed in with your ChatGPT account, and a free SEOmatic account. No API key needed for the browser sign-in.

Pricing

Free to connect. Search Console, audits and page checks have no limit; market data uses 5 free questions a month (plus a one-time 10 when you connect Search Console). Paid plans add agents that stage fixes for your approval. See pricing.

Full Docs

Endpoint, auth, every tool and what it costs: SEOmatic MCP server docs.

SEOmatic in Codex

What SEOmatic Does in Codex

Fix Titles and Meta in the Repo

Find pages with high impressions and low CTR, open the code that builds their title and description, and rewrite it once for every page that shares it.

Unindexed Pages, Traced to Code

Inspect up to 50 URLs per call in Google's index, then search the repo for the noindex, canonical or robots rule behind each exclusion.

Pre-Deploy Audit for Next.js

Run SEOmatic's audit on a public preview deploy before you merge, and compare it with production page by page.

Vibe-Coded Site Cleanup

Exported a site from Lovable or Bolt? Codex finds the missing titles, duplicate descriptions and broken internal links, then fixes them in the export.

Relaunch and Redirect Checks

After a migration, check that old URLs redirect, new ones get indexed, and nothing important fell out of Google.

SEO Checks in CI

Run codex exec with an API key on each deploy or each Monday, and get a short list of what broke.

On a site you build in code, most SEO bugs are code bugs: a metadata function with no fallback, a robots rule that catches too much, a canonical that points at the wrong host. Codex with SEOmatic finds them from real Google data and fixes them where they live.

Example: Ask Codex About Your Site

An example on the Acme Plumbing demo site. You ask Codex:

“Which of my pages has Google not indexed, and is the cause in our code?”

Codex calls SEOmatic:

site_pages: page inventory, 64 URLs
gsc_indexing: batch inspection of 50 URLs
gsc_performance: /service-areas/* pages, Sep 12 to Oct 9 (28 days)
Searched the repo for robots metadata

Codex answers:

6 of the 50 URLs I inspected are not indexed.

4 are /service-areas/ pages, marked "Excluded by noindex tag". The cause is in app/service-areas/[city]/page.tsx: robots is set to noindex whenever publishedAt is empty, and those four were imported without it. From Sep 12 to Oct 9 (28 days) they earned 0 clicks, while the indexed city pages earned 310. I changed the check to noindex drafts only.
2 are blog posts marked "Crawled, currently not indexed". That is thin content, not code: under 300 words each.

Review the diff and deploy, then ask me to inspect the four URLs again.

Also try:

“Audit the live site and map each issue to a file”
“Which pages get impressions but no clicks?”
“Check the preview deploy before I merge”
“Fix the duplicate titles across my blog”

SEO Prompts to Try in Codex

Run these in a Codex session inside your site's repo, in the CLI or the IDE extension:

“Use SEOmatic to audit https://example.com, then find the file responsible for each issue.”
“Which pages have Google not indexed? Check our robots and canonical code for the cause.”
“Find pages with lots of impressions and few clicks over the last 28 days, and rewrite their title logic.”
“Audit the preview deploy at https://preview.example.com before I merge, and compare it with production.”
“We moved from /es/ to /en/. How many old /es/ URLs are still indexed, and which return 404?”
“Fix every page that ships without a meta description, starting with the ones that get the most impressions.”

How It Works, Step by Step

You add SEOmatic with codex mcp add and sign in once in the browser.
You ask Codex an SEO question from your repo.
Codex calls SEOmatic to read Search Console, inspect indexing or audit the live site, and gets real results back, with the date range for every number.
It searches your code for what produces each problem and proposes a change, inside the sandbox and approval rules you set for Codex.
You review the diff and deploy, then Codex re-checks the live URL to confirm the fix.

For checks you want on a schedule, run the same prompt with codex exec in a script or CI job, using an API key instead of the browser sign-in.

How to Connect SEOmatic to Codex

One command, one browser sign-in and one line of config. About a minute, with no Google Cloud project.

Add the server. In your terminal, run: codex mcp add seomatic --url https://app.seomatic.ai/api/mcp
Sign in. Your browser opens: sign in or create a free SEOmatic account and pick your site. If no browser opened, run codex mcp login seomatic.
Give SEOmatic time to load. Codex waits 1 second for MCP servers when a session starts, then goes on without them. Add mcp_optional_startup_grace_ms = 10000 near the top of ~/.codex/config.toml, above the first [section], so SEOmatic's tools are there from your first message.
Connect Search Console. If your workspace has no Search Console yet, Codex gives you a one-click link the first time it needs your data.
Ask your first question. Start Codex in your repo and ask “Use SEOmatic to audit my site and find the code behind each issue.”

Codex setup

# Add SEOmatic (opens your browser to sign in)
codex mcp add seomatic --url https://app.seomatic.ai/api/mcp
# Only if no browser opened:
codex mcp login seomatic

# ~/.codex/config.toml
# This line goes at the top, above the first [section]:
mcp_optional_startup_grace_ms = 10000

[mcp_servers.seomatic]
url = "https://app.seomatic.ai/api/mcp"

# Headless or CI: use a workspace API key instead
export SEOMATIC_API_KEY=smk_live_...
codex mcp add seomatic --url https://app.seomatic.ai/api/mcp \
  --bearer-token-env-var SEOMATIC_API_KEY
# then add required = true under [mcp_servers.seomatic]

# Optional: SEOmatic's 21 SEO skills
npx -y skills add Minh42/seomatic-mcp --full-depth -a codex

Create a workspace API key in Settings, AI Agents, API Keys. Keep it in an environment variable or your CI secrets, never in the repo.

MCP server, API key or skills: how should Codex connect?

Route	Best for	How
MCP server with OAuth	Most developers, in the Codex CLI, the IDE extension and the ChatGPT desktop app	`codex mcp add seomatic --url https://app.seomatic.ai/api/mcp` opens your browser to sign in (`codex mcp login seomatic` if it does not). Saved in `~/.codex/config.toml`. No terminal? In the ChatGPT desktop app: Settings, MCP servers, Add server. In the IDE extension: the gear menu, MCP servers, Add server. Pick Streamable HTTP, paste the URL, save, restart, then select Authenticate.
MCP server with an API key	CI, containers and codex exec on a machine with no browser	Export `SEOMATIC_API_KEY`, then add the server with `--bearer-token-env-var SEOMATIC_API_KEY`. Add `required = true` under `[mcp_servers.seomatic]` so a run stops if SEOmatic cannot connect.
Skills	Teaching Codex SEOmatic's playbooks: seo-audit, striking-distance, weekly-brief and 18 more	`npx skills add Minh42/seomatic-mcp --full-depth -a codex`. SEOmatic's 21 SEO skills land in `~/.agents/skills`. All of them: SEO skills.

Pick the MCP server with OAuth. One command and a browser sign-in, no key to store, and it works the same in the terminal and the IDE. Add the skills on top when you want Codex to run audits the same way every time.

Fix SEO on Your CMS From Codex

Codex reads Google Search Console through SEOmatic, and the fixes you approve go live in your CMS. Pick your platform for the exact steps:

Is Codex the Same as ChatGPT?

No. Both come from OpenAI and use the same account, but they do different jobs.

Codex is the coding agent: the Codex CLI, the IDE extension and Codex inside the ChatGPT desktop app. It reads your repo, runs commands and changes code. This page is about Codex.
ChatGPT is the chat app. Use it to read your numbers and approve fixes without touching code: ChatGPT SEO.
OpenAI dots are always-on agents inside ChatGPT that work between conversations, like a weekly SEO check-in: OpenAI dots.

All three reach the same SEOmatic server and workspace, so your free questions and your approvals carry across.

What Is Free and What Is Paid

Connecting is free, and so is the SEOmatic account behind it: no card. Free covers the diagnosis with no limit: Search Console reports and insights, site audits of up to 30 pages, live page analysis, and your AI visibility results.

Live market data, like keyword volumes, backlink profiles and competitor domains, uses free questions: 5 a month, plus a one-time 10 bonus questions when you connect Google Search Console. One question covers up to 5 lookups.

Paid plans remove the question limit and add the treatment: agents stage fixes on your site (titles, descriptions, content updates, technical fixes, internal links) and run campaigns and fresh AI visibility scans. Every paid plan starts with a 14-Day Trial for $1, credited to your first payment. See pricing.

When you make the code change yourself, the free plan covers most of the work: finding the problem is the part SEOmatic does, and Codex writes the fix. Paid plans matter when you want SEOmatic's agents to change pages in a CMS for you. Codex usage itself is billed by OpenAI under your ChatGPT plan.

Nothing Changes on Your Site Without Your Approval

Codex changes your code inside its sandbox, with the approval rules you set, and you review the diff before anything ships. On the SEOmatic side, anything that would change your live site through a connected CMS is staged, never pushed. A staged change is a proposal: it says what will change and why, and in Approval mode nothing touches your site until you approve it. The assistant records your decision, and it is told never to approve anything on its own judgment. Approved fixes start within seconds, the page's previous state is stored, and any applied change can be rolled back. Changes that could take a page out of Google, like a noindex, need an extra explicit confirmation.

Keep Exploring

Prefer chat to code? See ChatGPT SEO. Want a weekly check-in without asking? See OpenAI dots. Other coding agents: Claude Code, Cursor and GitHub Copilot. Explore the site audit, page indexing and technical SEO fixes. Prefer the command line without an agent? The same tools run through the SEO API. All assistants: AI assistants. Full reference: MCP docs.

Using another agent? See ChatGPT, OpenAI dots, Claude Code, Cursor, or every AI agent.

Frequently Asked Questions

How do I connect SEOmatic to Codex?

Run codex mcp add seomatic --url https://app.seomatic.ai/api/mcp. Your browser opens so you can sign in to SEOmatic and pick your site; if it does not, run codex mcp login seomatic. The setup is saved in ~/.codex/config.toml, so the Codex CLI, the IDE extension and Codex in the ChatGPT desktop app all see it. Then start a new Codex session.

Can Codex do SEO?

Codex can change titles, meta tags, robots rules and templates in your code, but on its own it cannot see your rankings or which pages Google has indexed. With SEOmatic connected, it reads your real Search Console data, inspects indexing and audits your live site, then fixes the cause in your repo.

Is Codex the same as ChatGPT?

No. Codex is OpenAI's coding agent for the terminal, the IDE and the ChatGPT desktop app. ChatGPT is the chat app, and OpenAI dots are always-on agents inside ChatGPT. All three can use SEOmatic, and they share one SEOmatic account.

Do I need an API key?

Not for normal use. codex mcp add and codex mcp login sign you in through the browser with OAuth. Use an API key only on machines with no browser, such as CI: export SEOMATIC_API_KEY and add the server with --bearer-token-env-var SEOMATIC_API_KEY.

Can I run SEO checks with codex exec in CI?

Yes. Add the server with an API key on that machine and set required = true under [mcp_servers.seomatic], so the run fails loudly if SEOmatic cannot connect. Then run a prompt like codex exec "Audit the preview deploy with SEOmatic and list anything that would hurt rankings" on each deploy or on a schedule. SEOmatic's read tools run without a prompt. codex exec cannot answer approval prompts, so keep CI runs to checks and reports.

What are the SEOmatic skills for Codex?

21 playbooks that tell Codex how to run common SEO jobs well, from an SEO audit and striking distance keywords to traffic drop diagnosis, AI visibility and client reports. Install them with npx skills add Minh42/seomatic-mcp --full-depth -a codex. They are optional; the MCP server works without them.

Are the numbers real?

Yes. They come from your own Google Search Console and Google's URL Inspection data through SEOmatic, and each answer names its date range, like Sep 12 to Oct 9, 28 days. You can check any number in Search Console.

Is it free?

Yes. The SEOmatic account is free with no card. Search Console reports, site audits and page checks are free with no limit. Live market data (keyword volumes, competitors, backlinks) uses free questions: 5 a month, plus a one-time 10 when you connect Search Console. Paid plans remove the limit and add agents that stage changes in your CMS. Codex itself is billed by OpenAI.

Can it change my site without asking?

No. By default every change SEOmatic proposes waits for your approval before it touches your site, and your assistant is told never to approve on its own. Approved changes are stored with the page's previous state, so any edit to an existing page can be rolled back. If you later want low-risk fixes to go ahead on their own, you can turn that on in your autonomy settings; changes to your URLs or indexing, and new content, still wait for you.

Codex does not see the SEOmatic tools. What should I check?

Run codex mcp list to confirm seomatic is there and signed in. If it is missing, run codex mcp add again. If it asks for sign-in, run codex mcp login seomatic. If seomatic is listed but Codex says it has no SEOmatic tools, Codex most likely started without it: it waits only 1 second for MCP servers when a session starts. Add mcp_optional_startup_grace_ms = 10000 at the top of ~/.codex/config.toml (or required = true under [mcp_servers.seomatic]), restart the ChatGPT desktop app or the IDE extension, and start a new session. Type /mcp in the session to see the servers it loaded. Still missing? Remove any SEOmatic plugin and keep only the [mcp_servers.seomatic] entry.

Can it audit localhost?

No. SEOmatic fetches pages from the public internet, like a search engine does, so it cannot reach localhost. Point it at a public preview deploy instead.

SEOmatic in other AI agents

Same server, same tools, same approval rules. Pick the agent that fits the job.

Claude Code

One command connects your Search Console to the terminal, so Claude Code fixes SEO in the code.

Grok Build

Two commands give Grok Build your real Search Console data, so it can find what costs you clicks and fix it in the code.

Kimi K3

Kimi K3 in Kimi Code CLI, reading your real Search Console and fixing what it finds in your repo.

DeepSeek

DeepSeek, working from your real Search Console data through the SEOmatic plugin for DeepSeek Harness.

Cursor

One mcp.json entry, and Cursor's agent works from your real Search Console data while it edits your code.

GitHub Copilot

Add SEOmatic to .mcp.json and Copilot works from your real SEO data.

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