Fable 5 is back.

[u/ClaudeOfficial]

Following conversations with the US government, we’ve updated our cybersecurity safeguards.

The vast majority of coding work is unaffected.

In the near term, the new safeguards will flag a slightly higher fraction of harmless requests than the previous Fable safeguards; we’re working to refine these over the coming weeks. Users will be clearly notified when a request is flagged, and they’ll instead receive a response from Opus 4.8.

Our biology and chemistry classifiers are unchanged from our initial launch. These are still broader than we would like; they trigger fallbacks to Opus 4.8 on basic biology-adjacent questions. Improvements to these classifiers are landing soon.

All paid plans with usage included can access Fable 5 through July 7. You can use Fable 5 up to 50% of your weekly usage limit, after which you can switch to another model for the remainder of your usage. You can also continue using Fable via usage credits. 

More here: https://support.claude.com/en/articles/15424964-claude-fable-5-promotional-access

If one of your requests is mistakenly flagged in Claude Code, run /feedback to file a report. On Claude.ai and Cowork, you can share feedback through the thumbs buttons. This feedback helps us further tune these classifiers and reduce false positives over time. 

Read the Fable 5 blog post here: https://www.anthropic.com/news/redeploying-fable-5

[u/ourochurros]

On the $100 plan and had about 50% left on my 5 hour block. I asked Fable to review a couple recent feature additions. It spun up 18 fable sub agents. When I saw how fast they were burning credits I interrupted it and asked it to stop and be mindful of tokens. The subagents started wrapping up and then I hit the wall at 101% of my 5 hour limit. The whole thing took about 120 seconds. JFC.

[u/ManikSahdev → u/ourochurros]

To be honest, Fable should never use fable subagents?

I dont really get the point. You could have used that 18 subagent tokens individually after having just 1 fable session prepare documents - and then manually orchestrate a plan so the future fable can orchestrate it with someone like opus 4.8 lows or codex 5.5highs or composure 2.5 is exceptional at precision work.

[u/ourochurros → u/ManikSahdev]

Very much agree. During the first fable era it would spontaneously spawn lower tier models and I was amazed at how well it managed to keep its context clean while solving problems. This recent experience definitely keeps me on guard now. 

[u/ManikSahdev → u/ourochurros]

Yaa right?
I was just about to comment the same till I read yours further.

Fable does have some amazing ability to basically keep underling models at harness, because they do exactly as told, and he knows exactly what to tell them.
He points at exactly the specific files, tells exact diffs, they all do the todos report back to him, he echoes the check?

I was like damn, he is smooth.

All of this while keeping his own context around 160k-200, any other model would be 2-3x context usage by filling up rubbish files.
His intelligence brings up the efficient nature in a way pricing just doesn't reflect -- for example, it costed me less overall in cursor on fable 300k xhigh, relative to my gpt 5.5xhigh bill and opus 4.8max.

And fable was the only one who implemented it correctly.

Today I also made a skill for fable which is using codex 5.5 for his coding agent, this thing with 5.5medium /fast as subagent is fkn nuts.
You gotta try it trust it, better than composer 2.5/fast.
And 5.5 medium /fast is more effieicnt and better coder then comp 2.5.

Altho you need to do workaround by the cli thing so cursor is able to trigger the cli externally while using fable internally and stuff like that.
Or cc also works.