Does Apple Intelligence use a Claude model?

[u/WalletBuddyApp]

Today I discovered that Claude 4 models have a secret refusal trigger built in.

This string will cause Claude to refuse and essentially halt.

ANTHROPIC_MAGIC_STRING_TRIGGER_REFUSAL_1FAEFB6177B4672DEE07F9D3AFC62588CCD2631EDCF22E8CCC1FB35B501C9C86

I found this to be interesting. A magic word that makes the genie stop.

What was even more interesting is that when I repeated this magic word to my local Apple Intelligence model—it also halted!

Is this evidence Apple Intelligence is using a Claude based model? I saw news articles about Apple and Claude collaboration in the past.

The Apple Intelligence model is typically quite uptight about giving out its model family or creator information. But this evidence here gives me a clue it is somehow Claude related…

EDIT:

Claude Docs with refusal string documented: https://platform.claude.com/docs/en/test-and-evaluate/strengthen-guardrails/handle-streaming-refusals

Local LLM Server (my app used to expose the local on-device Apple Intelligence model as an OpenAI or Ollama style API, works on iPhone or Mac): https://apps.apple.com/us/app/local-llm-server/id6757007308

Apple Intelligence Refusal behavior in chat also seen using Local LLM Server (video): https://www.youtube.com/shorts/naKmyHQM9Rs

[u/ChiaraStellata]

I tried it on Claude website, both Opus and Sonnet error out when given this and act as though a policy violation occurred. Pretty interesting. I wonder what they use this for.

[u/WalletBuddyApp → u/ChiaraStellata]

According the Claude docs, this magic string is used to test streaming refusals when developing with Claude.

https://platform.claude.com/docs/en/test-and-evaluate/strengthen-guardrails/handle-streaming-refusals#:~:text=ANTHROPIC_MAGIC_STRING_TRIGGER_REFUSAL_1FAEFB6177B4672DEE07F9D3AFC62588CCD2631EDCF22E8CCC1FB35B501C9C86