# Codex MCP: add 1folder so Codex saves and reads your files

> Add 1folder to Codex and it can save handoffs and reports to files that Claude Code, Cursor or ChatGPT can read next. Run codex mcp add 1folder --url https://1folderapp.com/mcp, then codex mcp login 1folder. Sign in, choose the folders Codex may use and press Allow. Check it with codex mcp list, then ask Codex to save one handoff file.

*Picture: Codex (reads a project brief and records what it checked) connected to one 1folder holding Checkout handoff (a page saved by Codex, version 2) and Release criteria (a page saved by you).* Codex saves Checkout handoff with the code revision, checks and next action. The shared folder keeps that page beside the release criteria you supplied.

## Connect Codex to 1folder

1. **Add 1folder from your terminal.** Run codex mcp add 1folder --url https://1folderapp.com/mcp. This registers the remote address; it does not yet prove that the app can open your files.

   *Picture: Adding 1folder to Codex by typing one line: codex mcp add 1folder --url https://1folderapp.com/mcp*
2. **Sign in to 1folder.** Run codex mcp login 1folder and complete the sign-in in the browser. Use codex mcp list to check the entry, and /mcp inside Codex to inspect active servers.
3. **Choose the folders and press Allow.** Pick the Engineering space or just the folders for this work. Choose View and edit to save files, or View only to review them, then press Allow.

   *Picture: 1folder’s Allow page: “Codex wants to use your 1folder”, with Only the folders I pick in Engineering and View and edit chosen, then Allow.*
4. **Check one saved file.** Ask Codex to save Checkout handoff and return its private link. Open the file and check the actual contents before handing over more work.

   *Picture: In Codex, you type: “Save Checkout handoff in my 1folder Engineering folder and give me its private link.” Codex saves Checkout handoff (a page saved by Codex, version 1) to 1folder.*

## Requests to try with the connected app

- In Codex: “Read Release criteria in my 1folder Engineering folder. Compare them with this checkout and list what is still unverified before editing.”
- In Codex: “Save Checkout handoff in 1folder with the repository, branch, commit, uncommitted changes, decisions, checks actually run and next action. Return the private link.”
- In Codex: “Read the current Checkout handoff, check its revision against this checkout, then update that same page with your verified test results.”

## Codex MCP servers connect tools; they do not share a session

An MCP connection lets Codex use a service’s tools while it works. Codex supports local programs as well as remote HTTP servers. For 1folder, the remote address is enough: there is no helper package to run on your computer.

Keep source code and normal repository history in Git. Use 1folder for a project brief, decisions and a [current handoff](https://1folderapp.com/how-to/claude-code-handoff.md) that another app or person can open. The connection does not copy your Codex transcript or make another app resume the same session.

## Codex CLI MCP commands to use

| | Run in your terminal | What it checks or changes |
|---|---|---|
| Add | codex mcp add 1folder --url https://1folderapp.com/mcp | Registers the remote server address |
| Sign in | codex mcp login 1folder | Starts sign-in for the registered server |
| List | codex mcp list | Shows your configured servers |
| Inspect in a session | /mcp inside Codex | Shows active MCP servers in the terminal interface |

## Where the configuration lives

OpenAI documents ~/.codex/config.toml as the default configuration file. A trusted project can use .codex/config.toml for project-scoped settings. MCP entries live under mcp_servers, with a url for a remote HTTP server. The desktop app, CLI and IDE extension share the configuration for the same Codex host.

If an entry appears in one place and not another, check which machine and configuration file that Codex uses. Setting it up on your laptop doesn’t set it up on another computer.

## Codex MCP login: common checks before trying again

If the server is listed but cannot open your files, finish codex mcp login 1folder and the 1folder Allow page. Registration alone is not a completed sign-in. For a terminal without a local browser, OpenAI documents codex mcp login 1folder --no-browser: open the printed authorization address in a browser and paste the full redirect address back as instructed.

If Codex can read but cannot save, check View and edit for the 1folder connection. If it cannot find a particular file, check that the file is in the space or folders you allowed. Repeating the add command cannot widen that access.

## Make the first saved result useful

- Include a commit and working-tree state in Checkout handoff. “Tests passed” is only meaningful when it says which tests ran against which code.
- Ask Codex to mark incomplete work and checks it did not run. The next app should verify the checkout before trusting the handoff.
- Request updates to the existing file. Each save creates a version attributed to the app, so you can compare or undo changes to the saved page.
- Use its private link with connected apps. Only the person can [make the file public](https://1folderapp.com/how-to/share-files-with-clients.md). A 1folder undo changes the saved file, not your repository.

## Questions

### What is the Codex MCP add command for 1folder?

Run codex mcp add 1folder --url https://1folderapp.com/mcp. Follow it with codex mcp login 1folder to complete sign-in.

### Does the CLI setup also apply to the IDE extension?

OpenAI says the CLI, IDE extension and desktop app share MCP configuration for the same Codex host. A different host may have a different configuration.

### Why does codex mcp login need a browser?

The sign-in lets you choose the 1folder account, folders and editing access. For terminals without a local browser, OpenAI documents the --no-browser login option and a copy-and-paste completion flow.

### Can Claude Code read what Codex saved?

Yes. Give [Claude Code](https://1folderapp.com/integrations/claude-code-mcp.md) its own connection to the same folder and ask it to read the current handoff. This shares the saved file, not Codex’s chat history.

### Does 1folder sync my repository or commits?

No. It keeps pages and files you save. Use Git to move code between checkouts and confirm that the saved handoff matches the actual revision.

## Sources

- [OpenAI documentation: Connect Codex to an MCP server](https://learn.chatgpt.com/docs/extend/mcp?surface=cli)
- [OpenAI Developers: Docs MCP, Codex setup](https://developers.openai.com/learn/docs-mcp)

Checked on November 11, 2026.

## Read next

- [Claude Code MCP: add 1folder so your plans and handoffs are kept](https://1folderapp.com/integrations/claude-code-mcp.md): Add 1folder to Claude Code with one command. It saves plans, handoffs and reports you can open anywhere, and Codex, Cursor or ChatGPT can pick them up.
- [Use Claude Code and Codex together on the same files, with Cursor too](https://1folderapp.com/integrations/claude-code-and-codex-together.md): Use Claude Code, Codex and Cursor together with a saved handoff, code revision and checks. Connect each app once and keep the next agent’s starting point clear.
- [Cursor MCP: add 1folder so Cursor saves and reads your files](https://1folderapp.com/integrations/cursor-mcp.md): Add 1folder to Cursor in mcp.json and sign in. Cursor then saves briefs and notes to your files, where Claude Code, Codex or ChatGPT can pick them up.
- [Claude Code handoff: pass work to a new session](https://1folderapp.com/how-to/claude-code-handoff.md): Write a Claude Code handoff with the revision, changed files, checks and next steps. Compare HANDOFF.md, resume and compact, and save it to 1folder to share.

[Add 1folder to your AI app, free](https://1folderapp.com/signin) · [All resources](https://1folderapp.com/resources.md)

Website: https://1folderapp.com/ · Contact: hello@1folderapp.com