Make Claude Fable 5 Use GPT 5.6 Sol: Here's How

What you need

• Claude Code with access to Claude Fable 5

• A ChatGPT subscription for Codex (I find the $20 plan is enough for this use)

• The Codex plugin GitHub link from the description

Step by step

1. 1

   Copy the plugin link

   0:51

   Open the description and copy the GitHub link for the official Codex plugin for Claude Code. The plugin comes from OpenAI and is free. It gives Claude Code access to Codex, OpenAI's equivalent of Claude Code, which runs on the latest GPT models.

   Codex plugin for Claude CodeCopy

   https://github.com/openai/codex-plugin-cc

2. 2

   Ask Claude Code to read the link with web fetch

   0:58

   Open Claude Code, paste the link and ask it to check the page using web fetch. Naming web fetch keeps Claude from switching to browser automation, which is much slower and uses more tokens when all you need is the text on a page.

   PromptCopy

   Hey, Claude, can you please go to that link just using web fetch and tell me what's inside of there? Then I will need your help setting it up.

3. 3

   Have Claude install the plugin

   2:44

   Read Claude's summary, then ask it to install the plugin. If it says your workspace already has it, you can still ask for a fresh install, which is what I do in the video. Wait a few seconds for the install to finish.

   PromptCopy

   Could you please install this for me anyways?

4. 4

   Switch the model to Fable 5

   3:42

   Set Claude Code to Fable 5. Fable 5 plans and delegates the work. The Codex agents do the tasks, so you don't spend Fable 5 tokens on the tasks themselves.

5. 5

   Test it with two Codex subagents

   3:49

   Ask Claude to launch two Codex subagents for a small task. I ask for quick AI news from France and Spain. Claude Code should report that it is launching two Codex subagents, each one running GPT 5.6.

   Test promptCopy

   Can you please use two Codex subagents to go ahead and fetch me the latest news, both in France and also in Spain, for AI trends? Make sure that it's very quick. I don't want something very detailed.

6. 6

   Check the subagents and the results

   4:24

   Open each subagent in Claude Code to watch it work. When they finish, the Codex agents send their answers back to Claude Code, which gives you the combined reply. The Codex agents use your ChatGPT tokens, not your Fable 5 tokens.

7. 7

   Split the work between the two

   4:53

   Give Fable 5 the jobs where taste matters, like building interfaces. Send Codex the jobs where I find it stronger: spotting security risks, back-end work and long tasks. Also have Codex review Fable's or Opus's output, because one model often catches mistakes the other misses.

Watch next

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• 26:07Master Codex Desktop in 30 MinutesUse Codex directly on its own, with skills, subagents, goals and scheduled tasks.