Bring your Claude projects into Codex.
Start with one project. Bring across its instructions, useful files and current decisions, then try a task you already know.
Each project becomes a local folder in your Documents, opened in Codex. This guide does not use ChatGPT Projects. Your old Claude chats stay in Claude; the handover gives Codex the context to continue.
Gather one project.
- In your computer’s Documents folder, create Happy Haus AI. Inside it, create one folder for each Claude project you move. For example:
Documents/Happy Haus AI/Marketing. - Open the project in Claude. Copy its project instructions into a document called
Claude instructions.txtin that folder. - Put copies of the project’s reference files and useful outputs in the same folder. Use your original files where possible. Copy any text-only project knowledge into a document too.
Keep the Claude project available while you check the move.
Want a backup of your old chats too?
For a personal Free, Pro or Max account: Settings → Privacy → Export data. Claude emails a download link that expires after 24 hours.
Team or Enterprise exports require the organisation’s Primary Owner. The export is a backup, not a ready-made Codex project. Check its contents and gather reference files separately.
Save what matters from your chats.
Paste this into the most useful chat in the project.
Review the reply, then save it as Project handover.txt in your folder. Repeat for other chats with important decisions. Claude may not know what happened in every project chat.
Open your project folder.
- Open Codex on your computer and sign in with the account you’ll use for Happy Haus.
- Add or open a local project in Codex and select your folder, such as
Documents/Happy Haus AI/Marketing. Choose the local folder option if asked where to work. Button names may vary with your app version. - Start a new Codex chat inside that folder’s project. Keep each project’s files and instructions in its own folder.
You now have the files in one place. Next, give Codex the instructions for using them.
Let Codex organise the context.
Paste this into the new project chat.
AGENTS.md is the file Codex reads for project instructions. Review what it creates, then start a fresh project chat to check it.
Try one familiar task.
Ask Codex: “Read the project handover. What are we working on, what have we agreed, and what should happen next? Name the files you used.”
Then give it a small task you’ve already done in Claude and compare the result.
- Context: does it have the right goal and decisions?
- Style: does it follow your instructions?
- Files: can it use the references it needs?
- Jacks: ask Codex to read a known project from the Jacks database and confirm its name and current status. Check those against Jacks.
Reconnect Jacks through its MCP
- Get the official MCP server address or setup instructions from whoever manages Jacks. You may also be able to find the server details in Claude’s connector settings.
- In Codex, ask: “Help me add the Jacks MCP connection. Here are its setup instructions.” Complete any sign-in or authorisation in the app’s connection flow. If your organisation manages connections, ask its administrator to enable it.
- Test the known project above. Confirm access works before asking Codex to update Jacks.
Connections and sharing permissions need separate setup. Copying files does not carry Claude’s access into Codex. Keep passwords and tokens out of the handover documents.
Once this project works, repeat the same steps for the next one.